KR100470857B1 - Cleaning Ambient Air by the Movement of a Vehicle Having a Pollutant Treating Surface - Google Patents

Abstract

A method and apparatus for treating atmospheric air, comprising moving a vehicle having at least one atmospheric contact surface and a pollutant treating composition positioned over the surface through the atmosphere. Specific embodiments include coating a motor vehicle radiator with a pollutant treatment catalyst.

Description

Cleaning Ambient Air by the Movement of a Vehicle Having a Pollutant Treating Surface}

The present invention relates to an apparatus for purifying the atmosphere, and more particularly to a vehicle consisting of at least one atmospheric contact surface having a pollutant treating composition, and a related method and composition.

A review of the literature on pollutant control shows that the usual approach is to reactively purify waste streams entering the environment. If one pollutant or another is being detected or released too much, an alternative tendency has been to focus on the source of the pollutant, the source of the pollutant, or the waste stream containing the pollutant. Most process gaseous streams to reduce pollutants before entering the atmosphere.

It is known to treat the air destined into a confined space to remove undesirable components thereof. However, there was little effort to dispose of pollutants already in the environment, so the environment was left to its own self-cleaning system.

Literature that discloses purification of the environment is known. US Patent No. 3,738,088 discloses an air filtration device for purifying pollutants from ambient air by utilizing a vehicle as a mobile purification device. Various elements are disclosed that are used in combination with a vehicle to purify ambient air while the vehicle is traveling in the environment. In particular, piping is disclosed which regulates the air stream speed and directs the air to various filter means. The filter means may comprise a filter and an electrostatic precipitator. Post-filters using catalysts are disclosed to be useful for treating non-granular or aerosol pollutants such as carbon monoxide, unburned hydrocarbons, nitrogen oxides and / or sulfur oxides, and the like. German patent 43 18 738 C1 also discloses a physicochemical purification method of outside air. As carriers of conventional filters and / or catalysts, mobile vehicles are used which do not form the working part of the motor vehicle but are used directly to purify atmospheric air.

One other way is disclosed in US Pat. No. 5,147,429. A mobile air purifying station is disclosed herein. In particular, this patent features airships that collect air. This airship contains a number of different types of air purifiers therein. The disclosed air purification apparatus includes a wet scrubber, a filter, and a cyclonic spray scrubber.

The difficulty of the devices disclosed as forward purifying the air constituting the atmosphere is that they require new and additional equipment. Even the improved vehicles disclosed in US Pat. No. 3,738,088 require filters and piping that can include catalytic filters.

German Patent No. 40 07 965 C2, issued to Klaus Hager, discloses a catalyst consisting of a mixture of copper oxides converting ozone and copper oxides and manganese oxides converting carbon monoxide. The catalyst may be applied as a coating to a self heating radiator, an oil cooler or a charge air cooler. The catalyst coating consists of a heat resistant binder that also has gas permeability. Copper oxides and manganese oxides are widely used in gas mask filters and have been pointed out to have the disadvantage of being neutralized by water vapor. However, heating of the car surface while driving evaporates water. In this way, the desiccant is not required and the continuous use of the catalyst is possible.

Manganese oxides are known to catalyze the oxidation of ozone to form oxygen. Many commercially available types of manganese compounds and compositions are disclosed, including alpha manganese oxides that catalyze the reaction of ozone to form oxygen. In particular, it is known to use an alpha manganese oxide in the form of cryptomelan to catalyze the reaction of ozone to form oxygen.

Manganese oxide is described in O'Young's Symposium on Advances in Zeolites (Hydrothermal Synthesis of Manganese Oxides with Tunnel Structures, August 25-30, 1991). and Pillared Clay Structures. starting at p 348. Such materials are also disclosed in US Pat. No. 5,340,562 to Oh Young et al. Additionally, the form of ??-MnO ₂ is described in McKenzie, The Synthesis of Birnessite, Cryptomelane, and Some Other Oxides and Hydroxides of Manganese Mineralogical Magazine, December 1971, Vol. 38, pp. 493-502. For the purposes of this invention, the alpha manganese dioxide is a hole randayi agent _{(BaMn 8 O 16 · xH 2} O), Cryptococcus Gamelan _{(KMn 8 O 16 · xH 2} O), maenji Detroit _{(NaMn 8 O 16 · xH 2} O) and corona It is defined as including a root die _{(PbMn 8 O 16 · xH 2} O). Oh Young explained that this material has a three-dimensional framework tunnel structure (all are incorporated herein by reference as a hydrothermal reaction of manganese oxide having the tunnel structure of U.S. Patent No. 5,340,562 and Oh Young). For the purposes of the present invention ??-MnO ₂ is considered to be a 2 × 2 tunnel structure and is considered to include Hollandite, Cryptomellan, Manjirite and Coronite.

Summary of the Invention

The present invention relates to apparatus, methods and compositions for treating the atmosphere. For the purposes of the present invention, the term "atmosphere" is defined as the mass of air surrounding the earth.

The present invention relates to an apparatus and an associated method for treating an atmosphere comprising a vehicle and means such as a motor for moving the vehicle from one place to another through the atmosphere. The vehicle includes at least one atmospheric contact vehicle surface and a pollutant treating composition located on the surface. The atmospheric contact surface is the surface of the vehicle component in direct contact with the atmosphere. Preferred and useful atmospheric contact surfaces include car body surfaces, wind deflector surfaces, grill surfaces, mirror backs, and surfaces of "under the hood" components. Preferred atmospheric contact surfaces are located within the body of the motor vehicle, typically close to the engine, ie in the engine compartment. This surface is preferably the surface of the cooling means, such as a tube or a housing, consisting of an inlet passage of liquid or gas through the area where the refrigerant is walled and an outer surface arranged with fins to enhance heat transfer. Preferred atmospheric contact surfaces consist of finned outer surfaces and surfaces of radiators, air conditioner condensers, radiator fans, engine oil coolers, transmission oil coolers, power steering fluid coolers and air filled coolers, also referred to as intercoolers or aftercoolers. Is selected from. The outer surface of the air conditioner condenser and radiator has a high surface area and approx. To 135 ?? And typically due to relatively high ambient operating temperatures of up to 110 °.

One advantage of the present invention is that the atmospheric contact surface useful for supporting the pollutant treating composition can be the surface of an existing vehicle component. No additional filter or device is required to support the pollutant treating composition. Thus, the apparatus and method of the present invention can be placed in an existing part of a new car or remounted in an old car. Remounting may include applying a suitable pollutant treatment composition on an existing vehicle surface that contacts the atmospheric air as the vehicle travels in the atmosphere.

The present invention relates to compositions, methods and products for treating pollutants in air. Such pollutants typically range from 0 to 400 ppb ozone, more typically from 1 to 300 ppb, even more typically from 1 to 200 ppb; Carbon monoxide 0-30 ppm, more typically 1-20 ppm; And unsaturated hydrocarbon compounds such as C ₂ to about C ₂₀ olefins and 2 to 3000 ppb of partially oxidized hydrocarbons such as alcohols, aldehydes, esters, ethers, ketones and the like. Typical hydrocarbons that can be treated include, but are not limited to, propylene, butylene, formaldehyde, and other airborne hydrocarbons gases and vapors. Other pollutants present include nitrogen oxides and sulfur oxides. For ozone, the National Ambient Air Quality Standard is 120 ppb and for carbon monoxide 9 ppm.

Pollutant treatment compositions include catalyst compositions useful for catalyzing the conversion of pollutants present in the atmosphere into trouble-free materials. Alternatively, the adsorption composition can be used as a pollutant treatment composition that adsorbs pollutants that can be destroyed upon adsorption or stored for later processing.

Catalyst compositions can be used that can assist in the conversion of pollutants to harmless or less harmful compounds. Useful and preferred catalyst compositions include those that catalyze the reaction of ozone to form oxygen, to catalyze the reaction of carbon monoxide to form carbon dioxide, and / or to the reaction of hydrocarbons to form carbon dioxide with water. Special and preferred catalysts for catalyzing the reaction of hydrocarbons are useful for catalyzing the reaction of low molecular weight unsaturated hydrocarbons having 2 to 20 carbons and one or more double bonds, such as C ₂ to about C ₈ monoolefins. These low molecular weight hydrocarbons have been found to be sufficiently reactive to cause smog. Particular olefins that can be reacted include propylene and butylene. Useful and preferred catalysts can catalyze the reaction of both ozone and carbon monoxide, and preferably of ozone, carbon monoxide and hydrocarbons.

Ozone -Useful and preferred catalyst compositions for treating ozone include compositions consisting of manganese compounds comprising oxides such as Mn ₂ O ₃ and MnO ₂ , preferred compositions consisting of ??-MnO ₂ , with Cryptomellan being most preferred. Do. Other useful and preferred compositions include mixtures of MnO ₂ and CuO. Particular and preferred compositions are hopcalites containing CuO and MnO ₂ , and more preferably Carulite ^R which contains MnO ₂ , CuO and Al ₂ O ₃ and is sold by Carus Chemical Co. Is done. Another alternative composition consists of a refractory metal oxide support in which a catalytically effective amount of a palladium component is dispersed and preferably also comprises a manganese component. Also useful are catalysts consisting of a precious metal component, preferably a platinum component, on a support of co-precipitated zirconia and manganese oxide. The use of this co-precipitated support has been found to be particularly effective in enabling the platinum component to be used to treat ozone. Yet another composition that can lead to the conversion of ozone to oxygen consists of carbon, and palladium or platinum, manganese dioxide, carulite ^R and / or hopcalite supported on carbon. Manganese supported on refractory oxides such as alumina has also been found to be useful.

Carbon Monoxide —Useful and preferred catalyst compositions for treating carbon monoxide include compositions comprising a refractory metal oxide support in which a catalytically effective amount of a platinum or palladium component, preferably a platinum component is dispersed thereon. The most preferred catalyst composition for treating carbon monoxide consists of a reduced platinum group component supported on a refractory metal oxide, preferably titania. Useful catalytic materials include noble metal components, including platinum group components, which include metals and compounds thereof. Such metals may be selected from platinum, palladium, rhodium and ruthenium, gold and / or silver components. Platinum will also lead to the catalytic reaction of ozone. Also useful are catalysts consisting of a precious metal component, preferably a platinum component, on a support of co-precipitated zirconia and manganese dioxide. Preferably, this catalyst embodiment is reduced. Other useful compositions that can convert carbon monoxide to carbon dioxide include a platinum component supported on carbon or a support made of manganese dioxide. Preferred catalysts for treating such pollutants are reduced. Another composition useful for treating carbon monoxide is a platinum group metal component, preferably a platinum component, a refractory oxide support, preferably alumina and titania, and one or more metal components, preferably metal oxides selected from tungsten and rhenium components. In the form of

Hydrocarbons— useful and preferred catalyst compositions for treating unsaturated hydrocarbons, including C ₂ to about C ₂₀ olefins and C ₂ to C ₈ monoolefins, typically propylene, and partially oxidized hydrocarbons as listed above. Silver has been found to be of the same kind as listed for use in catalyzing the reaction of carbon monoxide and the preferred composition for unsaturated hydrocarbons consists of a reduced platinum and / or palladium component and a refractory metal oxide support for the platinum component. Preferred refractory metal oxide support is titania. Other useful compositions that can convert hydrocarbons to carbon dioxide and water include platinum components supported on carbon or on supports made of manganese dioxide. Preferred catalysts for treating such pollutants are reduced. Other compositions useful for converting hydrocarbons include a platinum group metal component, preferably a platinum component, a refractory oxide support, preferably alumina and titania, and one or more metal components, preferably metal oxides selected from tungsten and rhenium components. In form. Combining the platinum component with the palladium component improves the CO conversion with increasing cost, and the combination of the platinum component with the palladium component is most desirable when a higher conversion is desired and an increase in cost can be tolerated.

Ozone and Carbon Monoxide -A useful and preferred catalyst capable of treating both ozone and carbon monoxide consists of a support such as a refractory metal oxide support in which the precious metal component is dispersed. The refractory oxide support may consist of a support component selected from the group consisting of ceria, alumina, silica, titania, zirconia and mixtures thereof. Likewise useful as a support for noble metal catalyst components are co-precipitates of zirconia and manganese oxide. Most preferably, the support is used with a platinum component and the catalyst is in reduced form. This single catalyst has been found to effectively treat both ozone and carbon monoxide. Another useful and preferred noble metal component consists of a noble metal component selected from palladium and also a platinum component, with palladium being preferred. A combination of a ceria support and a palladium component results in an effective catalyst for treating both ozone and carbon monoxide. Other useful and preferred catalysts for treating both ozone and carbon monoxide are the platinum group component, preferably the platinum component and / or the palladium component, on the titania or on the zirconia and silica combination and more preferably the platinum component. Other useful compositions that can convert ozone to oxygen and carbon monoxide to carbon dioxide include a platinum component supported on carbon or on a support made of manganese dioxide. Preferred catalysts are reduced.

Ozone, Carbon Monoxide and Hydrocarbons -Ozone, Carbon Monoxide and Hydrocarbons, typically low molecular weight olefins (C ₂ to about C ₂₀ ) and typically C ₂ to C ₈ mono-olefins and partially oxygenated hydrocarbons as listed Useful and preferred catalysts capable of treating the stream consist of a support, preferably a refractory metal oxide support in which the precious metal component is dispersed. The refractory metal oxide support may consist of a support component selected from the group consisting of ceria, alumina, titania, zirconia and mixtures thereof, with titania being most preferred. Useful and preferred noble metal components consist of noble metal components selected from platinum group components, including palladium and / or platinum components, with platinum being most preferred. It has been found that the most effective catalysts for treating ozone, carbon monoxide and low molecular weight gaseous olefin compounds in the combination of titania support and platinum components are obtained. Combining the platinum component with the palladium component improves the CO conversion with increasing cost, and the combination of the platinum component with the palladium component is most desirable when a higher conversion is desired and an increase in cost can be tolerated. It is preferable to reduce the platinum group component with an appropriate reducing agent. Other useful compositions that can convert ozone to oxygen, carbon monoxide to carbon dioxide, and hydrocarbons to carbon dioxide include a platinum component supported on carbon, a support made of manganese dioxide, or a support made of a co-precipitate of manganese dioxide and zirconia. . Preferred catalysts are reduced.

The compositions can be applied by coating on at least one atmospheric contact vehicle surface. Particularly preferred compositions catalyze the destruction of ozone, carbon monoxide and / or unsaturated low molecular weight olefinic compounds at ambient or ambient operating conditions. Ambient conditions are atmospheric conditions. Ambient operating conditions refer to conditions of the atmospheric contact surface such as the temperature during normal operation of the vehicle without the use of additional energy on heating the pollutant treating composition. Certain atmospheric contact surfaces such as grills or wind deflectors may be at the same or similar temperature as the atmosphere. Preferred catalysts that catalyze the reaction of ozone may catalyze the reaction of ozone at ambient conditions in a low range of temperatures such as 5-30 ° C.

The atmospheric contact surface may be higher than the ambient ambient temperature because of the operation of the components below that surface. For example, the surface of the air conditioner condenser and the radiator is preferred because the atmospheric contact surface has a large surface area. If the vehicle uses an air-filled cooler, they are preferred because of their high surface area and operating temperature from ambient temperature to 250 ° C. Normally during ambient operating conditions the surface of these parts increases to a higher temperature level than the surrounding environment depending on their operating characteristics. After the vehicle motor has warmed up, these parts are normally Or less, typically from 40 to 110 degrees; Temperature in the range. The temperature range of this atmospheric contact surface allows to improve the conversion rate of ozone, carbon monoxide and hydrocarbon catalysts supported on the surface. The air charge cooler is about 130 ?? It operates at temperatures below, typically from 60 to 130 degrees Celsius.

Various catalyst compositions can be combined and the combined coating can be applied to the atmospheric contact surface. Alternatively, different surfaces or different parts of the same surface can be coated with different catalyst compositions.

The method and apparatus of the present invention are designed such that pollutants can be treated at ambient atmospheric conditions or at ambient operating conditions of the vehicle atmospheric contact surface. The present invention is intended for use in ambient conditions as well as at 0 ° C. Above, preferably at least 10 to 105 °, more preferably at 40 to 100 °, particularly for treating ozone by coating the motor vehicle atmospheric contact surface with a suitable catalyst useful for destroying such pollutants. useful. Carbon monoxide is preferably treated at atmospheric contact surface temperatures of 40 to 105 degrees Celsius. Low molecular weight hydrocarbons, typically unsaturated hydrocarbons having one or more unsaturated bonds, such as C ₂ to C ₂₀ olefins and typically C ₂ to C ₈ mono-olefins, are treated at atmospheric contact surface temperatures of 40 to 105 degrees Celsius. desirable. The percent conversion of ozone, carbon monoxide and / or hydrocarbons depends on the temperature and space velocity of the atmospheric air relative to the atmospheric contact surface, and the temperature of the atmospheric contact surface.

Thus, the present invention can, in the most preferred embodiment, reduce the levels of ozone, carbon monoxide and hydrocarbons present in the atmosphere at least without the addition of any mechanical features or energy sources to existing vehicles, especially motor vehicles. In addition, catalytic reactions occur at normal ambient operating conditions generated by the surface of such motor vehicle elements such that no changes are required in the construction or method of operation of the motor vehicle.

The apparatus and method of the present invention generally relates to treating the atmosphere, and variations of the apparatus can be considered for use in treating the volume of air in an enclosed space. For example, a motor vehicle having an atmospheric contact surface that supports the pollutant treating composition can be used by treating air in factories, mines, and tunnels. Such a device may include a vehicle used in such an environment.

While preferred embodiments of the present invention relate to the destruction of pollutants at ambient operating temperatures of atmospheric contact surfaces, it would be desirable to treat pollutants that require catalytic reaction temperatures above ambient or ambient operating temperatures of atmospheric contact surfaces. It may be. Such pollutants include hydrocarbons and nitrogen oxides and carbon monoxide untreated or bypassed at atmospheric contact surfaces. These pollutants typically range from at least 100 to 450 ?? It can be processed at high temperatures in the range. This can be done, for example, by the use of an auxiliary heating catalyzed surface. By auxiliary heating surface is meant that there is a supplementary means for heating the surface. Preferred auxiliary heating surfaces are the surfaces of electrically heated catalyzed monoliths such as electrically heated catalyzed metal honeycombs of the kind known in the art. Electricity can be provided by a battery or generator, such as present in a motor vehicle. The catalyst composition can be any known oxidation and / or reduction catalyst, preferably a three way catalyst (TWC) consisting of a noble metal such as platinum, palladium, rhodium, etc. supported on a refractory oxide support. The auxiliary heated catalyzed surface can be used in combination with the vehicle atmospheric contact surface, preferably afterwards, to further treat the pollutants.

As mentioned above, the adsorption composition can also be used to adsorb pollutants such as hydrocarbons and / or particulate matter for subsequent oxidation or subsequent removal. Useful and preferred adsorption compositions include group IIA alkaline earth metal oxides such as zeolites, other molecular sieves, carbon and calcium oxide. Hydrocarbons and particulate matter are 0 ?? Adsorbed at 110 ° to 110 ° and subsequently treated by catalytic reaction or incineration followed by desorption.

It is desirable to coat an area of a vehicle with a relatively high surface area that is exposed to high air velocity when the motor vehicle is traveling through the atmosphere. On land motor vehicles, particularly preferred atmospheric contact surfaces include radiators, fan blades, air conditioner condensers or heat exchangers, air-filled chillers, engine oil coolers, transmission oil coolers and types of wind deflectors used for the roof of truck cabs. Included.

Most preferably the atmospheric contact surface is the surface of the radiator. The radiator has a high surface area to promote cooling of the internal combustion engine fluid refrigerant. Application of the catalyst to be supported on the radiator surface can generally benefit from large honeycomb like surface areas with little or no impact on the radiator's cooling function. The large honeycomb like surface area allows maximum contact of the catalyst with air passing through the honeycomb like structure of the radiator. In addition, in many motor vehicles, the radiator is located behind the air conditioner condenser and protected by the air conditioner condenser.

The present invention includes a method of applying a pollutant treating composition onto an atmospheric contact surface of a motor vehicle. In particular, the present invention includes a method of coating a catalyst composition onto fin-like elements such as radiators, air conditioner condensers and air packed coolers.

In a traffic congestion area of a motor vehicle, it is calculated that there is a sufficient number of motor vehicles capable of treating to a considerable extent the pollutants to be treated according to the invention. For example, according to Southern California's Southern Coast Atmospheric Administration, there are approximately 8 million vehicles. If each car travels 20 miles a day in this area, it is calculated that all air in this area up to 100 feet can be circulated in a week through the radiator.

1 is a side schematic view of a truck showing the wind deflector on the roof of the truck cab with grills, air conditioner condenser, electric heating catalyst, air charge cooler, radiator, fan and engine.

2 is a partial schematic view of a motor vehicle showing a grill, an air conditioner condenser, a radiator and a fan.

3 is a front view of the radiator.

4 is a front view of the air conditioner condenser.

5 is a front view of a wind deflector of the type shown in FIG. 1;

6 is a front view of the truck of FIG.

7 is a partial cross-sectional view of the coated fin cooling element.

8 is a coated radiator picture of Examples 1 and 2. FIG.

9-14 and 16-17 are graphs of CO conversion versus temperature when different catalysts were used in Examples 4, 9-12, 14 and 15.

FIG. 15 is a graph of propylene conversion versus temperature based on Example 14.

18 is a graph of ozone conversion versus temperature, based on Example 17.

19 is an IR spectrum for Cryptomellan.

FIG. 20 is an XRD pattern for Cryptomellan as coefficients versus Bragg angle 2 ?? using the square root scale. FIG.

FIG. 21 is a graph of CO and hydrocarbon conversion vs. temperature based on Example 30.

The present invention relates to an air purification apparatus and method useful for a vehicle having means for transporting the vehicle through the atmosphere. At least one atmospheric contact surface comprising a pollutant treating composition (eg, catalyst or adsorbent) located on the surface as a vehicle moving through the atmosphere contacts the atmospheric air. When atmospheric air encounters a pollutant treating composition, various pollutants, including particles and / or gaseous pollutants carried in the air, may be catalytically reacted or adsorbed by the pollutant treating composition located on the atmospheric contact surface. Can be.

For those skilled in the art, the vehicle may be any suitable vehicle having a means of driving the vehicle, such as wheels, sails, belts, tracks and the like. Such means may include engines using fossil fuels such as gasoline or diesel fuel, gas engines powered by fuels such as ethanol, methanol, or methane gas, wind driven by wind sails or propellers, or solar energy or It may be powered by any suitable power means, including electrical forces in batteries or the like operated by a motor vehicle. Vehicles include passenger cars, trucks, buses, trains, boats, ships, airplanes, airships, balloons and the like.

The atmospheric contact surface may be any suitable surface that encounters and contacts air as the vehicle moves through the atmosphere. Preferably in motor vehicles, preferably in passenger cars, trucks and buses, the contact means may be a surface located towards the front of the vehicle, and the vehicle may contact air while traveling in the forward direction. Useful contact surfaces should have a relatively high surface area. Preferred contact surfaces are at least one partially closed in the vehicle. Preferred atmospheric contact surfaces are located under the hood, located inside the motor vehicle, and are typically located close to the engine, ie in the engine compartment. This surface is preferably the outer surface of the cooling means consisting of an inlet passage of liquid or gas through the area where the refrigerant is walled, such as a tube or a housing, or an outer surface on which fins to enhance heat transfer are arranged. Useful contact surfaces include liquids used in vehicles such as air conditioner condensers, radiators, air charge coolers, engine oil coolers, transmission oil coolers, power steering fluid coolers, fan covers, and radiator fans located within the vehicle's housing and / or ) Outer surface of the means for cooling the fluid comprising gas. The exterior of the useful contact surface of the vehicle is usually located in front of the housing and can be a wind deflector supported by a grill that is supported, or a roof of the cover of a large truck in general. Preferably, the contact surface is the front facing surface, the facing surface or the upper and lower facing surfaces of the vehicle. The front facing surface faces the front of the vehicle, and surfaces such as fins and condenser elements of the radiator face the side, top and bottom of the vehicle. The surface facing from the front to the rear of the vehicle in contact with the air may also be an atmospheric contact surface such as the back of the fan blade. Surfaces of aircraft engines, such as jet engine parts such as vanes, propellers and turbine rotors and / or stators, may be coated.

Preferred atmospheric contact surfaces in motor vehicles are located on engine cooling elements such as motor vehicle radiators, air conditioner condensers, air coolers, engine oil coolers, transmission oil coolers, also referred to as intercoolers or aftercoolers. Such elements typically have a high surface area associated with improved heat transfer. The high surface area is useful for maximizing contact of atmospheric air with the pollutant treating composition. All of these elements are known in the automotive sector. See, for example, Bosch Automoyive Handbook, 2nd Edition, pages 301-303, 320 and 349-351, published by Robert Bosch GMBH, incorporated herein by reference. In this document, a truck diesel engine with a radiator, intercooler and fan is described. Such elements may be coated with the pollutant treating composition of the present invention. Radiators and intercoolers typically operate at temperatures above ambient temperature. See also Taylor, The Internal Combustion Engine in Theory and Practice, Vol. 1: Thermo Dynamics, Fluid Flow, Performance, Second Edition, Rev. The MIT Press, 1985, for radiator and fin shaped designs 304 -306 page; page 392 for aftercoolers). The pages of Taylor's literature are incorporated herein by reference.

A reference is also made to a collection of literature published in 1993 by the Society of Automotive Engineers (Vehicle Thermal Management System Conference Proceedings SAE P: 263). The following documents are incorporated herein by reference. SAE Paper No. 931088 Ackerseder and Rab of Steyr Demmer Fusek, titled "Calculation and Design of Cooling System" (starting on page 157) and "Charge Air Cooler for Passenger Cars" by Collette of Valeo Thermique Moteur; Paper number 931092 (starting on page 187) entitled "State of the Art and Future Developments of Aluminum Radiators for Cars and Trucks" by Cairn and Eitel of Behr GMBH and Co .; SAE Article No. 931112, titled "Air Mix vs. Coolant Flow to Control Discharge Air Temperature and Vehicle Heating Air Conditioning Systems" by Rolling and Cumming of Behr of America, Inc. and by Schweitzer of Behr GmbH & Co. This includes a description of the radiator, air conditioner and air charge cooler structures used in motor vehicles. In addition, SAE Article No. 931115, entitled "Engine Cooling Module Development Using Air Flow Management Techniques," by El Bowini and Chen of Calsonic Technical Center, may be incorporated herein by reference. In dual motor vehicle applications, references 1 and 2 to describe conventional radiator and condenser structures are noted. For reference, SAE article number 931125 entitled "Durability Concerns of Aluminum Air to Air Charged Coolers" by Smith of Valeo Eingine Cooling Inc. is incorporated herein by reference.

The present invention may be understood by those skilled in the art with reference to the accompanying drawings 1 to 7.

FIG. 1 schematically illustrates a truck 10 containing various vehicle components that make up the atmospheric contact surface. These surfaces include the surfaces of the grill 12, air conditioner condenser 14, air charge cooler 25, radiator 16 and radiator fan 18. Above this truck is also shown a wind deflector 20 having a front deflecting surface 22. It is appreciated that the various components may have different relative positions in different vehicles.

1 to 4, preferred contact surfaces include front 13 and side 15 surfaces of the air conditioner condenser 14, front 17 and side 19 surfaces of the radiator 16, air charge cooler. Corresponding surfaces of 25 and front and rear surfaces of radiator fan 18 are included. These surfaces are located in the housing 24 of the truck. These are typically below the truck's hood 24 between the truck's front 26 and the engine 28. The air conditioner condenser, air charge cooler, radiator and radiator fan may be supported directly or indirectly by the housing 24 or a frame (not shown) within the housing.

2 shows a schematic diagram of an automobile assembly. Corresponding elements in FIGS. 1 and 2 have a common reference character. The motor vehicle includes a housing 30. There is a motor vehicle front face 32 with a grille 12 supported on the front face of the housing 30. The air conditioner condenser 14, the radiator 16 and the radiator fan 18 may be located in the housing 30.

1, 2 and 6, front and side surfaces of at least one of grill 12, air conditioner condenser 14, air charge cooler 25, and radiator 16; Front and rear of the radiator fan 18; And a pollutant treating composition on the contact surface in front of the wind deflector 20. The grill 12 may have a suitable grill grid shaped design that provides an opening 36 through which air passes as the truck 12 operates and moves through the atmosphere. The opening is defined by the grill grid 38. The grill grid 38 has a front grill surface 40 and a side grill surface 42. The front and side grill grid surfaces 40 and 42 can be used as atmospheric contact surfaces on which the pollutant treating composition is disposed.

1 and 4, the air conditioner condenser 14 consists of a plurality of air conditioner condenser fins 44. In addition, there is an air conditioning fluid conduit 46 that carries the air conditioning fluid into the condenser. The front and side surfaces of the air conditioning fin 44 and the front surface of the air conditioning conduit 46 can be the atmospheric contact surface on which the pollutant treating composition is disposed. As indicated, both the front 21 and rear 23 surfaces of the radiator fan 18 may be contact surfaces that support the pollutant treating composition.

The most preferred atmospheric contact surface is at the radiator 16 as shown in FIG. 3. A typical radiator 16 has a plurality of radiator corrugates or fins 50 located in the front radiator surface 17 and corresponding radiator plates or fin channels 52 passing through the radiator 16. It is desirable to coat not only the front surface 17 but also the side surfaces of the radiator plate 50 and channel 52 surfaces. The radiator is most preferred because it is located in the housing 24 or 30 and is protected from the front surface at least by the grill 12 and preferably the air conditioner condenser 14. In addition to the air entering the hood chamber 34 as the motor vehicle moves in the atmosphere, the radiator fan 18 draws air into it through the channel 52. Thus, the radiator 16 is located in front of the grill 12, the air conditioner condenser 19 and protected by them and in front of the radiator fan 18. In addition, as indicated above, the radiator has a high surface area for heat transfer purposes. According to the present invention, the pollutant treating composition can be effectively positioned on a high surface area without significantly adversely affecting the heat transfer function of the radiator.

The above description relates in particular to and describes the use of atmospheric treatment surfaces in devices such as radiator 16 and air conditioner condenser 14. As indicated, the atmospheric contact surface may be in the air fill cooler 25 referenced above and other suitable means for cooling the engine fluid, including known articles such as engine oil coolers, transmission oil coolers and power steering oil coolers. Common to all these cooling means is the housing or conduit through which the fluid passes. The housing consists of an inner surface in contact with the fluid and typically an outer surface in contact with the atmosphere of the frame of the vehicle and typically in the engine compartment. There are fins or plates extending from the outer surface of the cooler, housing or conduit to efficiently transfer heat from the fluid in these various devices.

A useful and preferred embodiment with each of these cooling means is described in FIG. 7. 7 is a schematic diagram of a cross-sectional view of the coated fin cooling element 60. This element comprises a housing or conduit defined by the housing or conduit wall 62. A passage or chamber 64 through which a fluid, such as an oil or cooling liquid or air conditioner fluid, passes is located in the conduit. Such a fluid is indicated by reference numeral 66. The housing wall includes an inner surface 68 and an outer surface 70. Plate or pin 72 is located and attached to the outer surface. There is a pollutant treating composition 74 which may be located on the outer surface 70 and the pins or plates 72 according to the present invention. In operation, the air stream contacts the pollutant treating composition to treat various pollutants.

Applicant hereby incorporated by reference herein the same patent application as assignee, filed under U.S. Patent Application 08 / 537,208, Representative Application No. 3794/3810, entitled "Pollution Treating Device and Methods of Making the Same". In addition, any of the embodiments of the apparatus of the present invention and methods of use thereof may optionally further comprise a compatible pollution treatment apparatus as disclosed in the above application.

The pollutant treating composition may be disposed on an exterior surface of the vehicle. As indicated, this composition may be disposed on grill 12 and on wind deflector surface 22 in the case of a truck shown in FIGS. 1 and 6. In addition, the pollution treatment composition may be placed on any of the various front facing surfaces as well as on the front surface of the mirror 54.

The use of the air filled cooler 25 represents a particularly effective atmospheric contact surface on which the pollutant treating composition can be supported. The operating temperature can reach 250 ° C. At such temperatures, the catalyst compositions of the present invention can more effectively treat ozone, hydrocarbons, and carbon monoxide pollutants. Particularly useful are compositions comprising precious metals such as platinum, palladium, gold or silver components. In addition, the catalyst may include a manganese compound such as manganese dioxide and a copper compound including a copper oxide such as carulite or hopcalite.

During normal operation, the vehicle moves in the forward direction, in which the front face 26 of the vehicle 10 initially contacts the atmospheric air. Typically, the vehicle travels through the air at a rate of about 1,000 miles / hour or less for jet airplanes. Speeds of up to about 300 miles / hour for land vehicles and water vehicles, more typically up to about 200 miles / hour, speeds of up to 100 miles / hour for motor vehicles, typically between 5 and 75 miles / hour Move at the speed of. Marine vehicles, such as boats, typically travel through sea at speeds of up to 30 miles / hour, typically 2 to 20 miles / hour. According to the method of the present invention, the relative speed (or surface velocity) between the atmospheric contact surface and the atmosphere is 0 to 100 miles / hour, typically 2 to 75 miles / hour, The case typically travels from 5 to 60 miles / hour. Surface velocity is the velocity of air relative to the pollutant treating surface.

In a motor vehicle, such as a truck 10 having a radiator fan 18, the fan moves to the atmosphere while the fan is moved to the grill 12, the air conditioner condenser 14, the air charge cooler 25 and / or the radiator ( 16) and draw atmospheric air in addition to the air passing through these elements. When the motor vehicle is idling, the relative face velocity of air drawn into the radiator is usually in the range of about 5 to 15 mph. As the motor vehicle moves through the atmosphere, the radiator fan relaxes the flow rate of air through the radiator. When a typical motor vehicle moves through the atmosphere at a speed of about 70 mph, the exit face velocity of the air is about 25 mph. According to the design of a motor vehicle using a radiator fan, the vehicle has a low plane speed of about 100% or less of the plane speed corresponding to the speed of the motor vehicle when the fan is used when idling. However, the face velocity of air with respect to the atmospheric contact surface is typically equal to the idling face velocity plus 0.1 to 1.0, more typically 0.2 to 0.8 times the vehicle speed.

According to the invention a large volume of air can be treated at relatively low temperatures. This occurs as the vehicle moves through the atmosphere. High surface area components of vehicles, including radiators, air conditioner condensers, and charge air coolers, typically have large front surface areas facing air streams. However, these devices are relatively narrow and typically range in depth from about 3/4 inch to about 2 inches and typically range from 3/4 to 1 inch in depth. The linear velocity of atmospheric air in contact with the front surface of such a device is usually in the range of up to 20, more typically 5 to 15 miles / hour. An indication of the amount of air treated when passing through a catalyzed vehicle part is often referred to as space velocity or more precisely volume hourly space velocity (VHSV). This is measured as the volume of air per hour passing through the volume of the catalyst product (corresponding to the volume of the catalyzed element). This is based on cubic feet of air per hour divided by cubic feet of catalyst substrate. The volume of the catalyst substrate is the frontal area times the depth or axial length in the airflow direction. Alternatively, the volume hourly space velocity is the number of catalyst volumes based on the volume of catalyst product treated per hour. The space velocity is relatively high because of the relatively short axial depth of the catalyzed elements of the present invention. The volume hourly space velocity of air that can be treated in accordance with the present invention can be at least 1 million per hour. If the plane velocity of air for one of these elements is 5 miles per hour, a space velocity as high as 300,000 per hour can be achieved. According to the invention, the catalyst is designed to treat airborne pollutants at a space velocity in the range of as high as 250,000 to 750,000 per hour, and typically 300,000 to 600,000. According to the invention this is achieved even at relatively low ambient temperatures and at ambient operating temperatures of vehicle elements containing pollutant treatment compositions.

The ambient operating temperature of the atmospheric contact surface may vary depending on whether they are near a heat source in the vehicle or if they are surfaces of elements that function to cool parts of the vehicle. However, the contact surface, such as grill 12, wind deflector 20, is at ambient conditions. During normal operation, the means for cooling is operated above the ambient ambient temperature with a contact surface, such as the surface of the air conditioner condenser 14, and the radiator 16 and the air charge cooler 25 are operated at 130 ° C. The following range, typically 105 ?? It may be in the following ranges, usually 10 to 105 degrees, more typically 40 to 100 degrees, and 10 to 75 degrees. The air charge cooler 25 typically operates at temperatures between 75 and 130 degrees Celsius. The amount of contact surface may vary with the air conditioner condenser, the radiator and the air-filled cooler having 20 to 2,000 ft ² and the fan blade 18 usually having 0.2 to about 40 ft ² or less, given the front and rear surfaces.

The pollutant treating composition is preferably a catalyst composition or an adsorption composition. Useful and preferred catalyst compositions are those compositions which can catalytically trigger the reaction of pollutants targeted at the space velocity of the air, such as when air contacts the surface, and at the temperature of the surface at the point of contact. Typically, these catalytic reactions have a temperature of 0 ?? To 130 ??, more typically 20 ?? To 105 degrees, even more typically about 40 degrees; To 100 ?? It will happen when it is in range. There is no limit to the efficiency of the reaction as long as some reaction occurs. Preferably there is a conversion efficiency of at least 1% with the highest conversion efficiency possible. Useful conversion efficiencies are preferably at least about 5% and more preferably at least about 10%. Preferred conversion rates depend on the particular pollutant and pollutant treating composition. When ozone is treated with the catalyst composition on the atmospheric contact surface, it is preferred that the conversion efficiency is greater than 30% to 40%, preferably greater than 50%, and more preferably greater than 70%. In the case of carbon monoxide the preferred conversion is greater than 30% and preferably greater than 50%. Preferred conversion efficiencies for hydrocarbons and partially oxygenated hydrocarbons are at least 10%, preferably at least 15%, and most preferably at least 25%. This conversion rate is approximately 110 ° C for atmospheric contact surfaces. Particular preference is given to the following ambient operating conditions. This temperature is the surface temperature that occurs during normal operation of the atmospheric contact surface of the vehicle, which typically includes the surface of the radiator and the air conditioner condenser. If there is supplemental heating of the atmospheric contact surface, such as by having an electrically heated catalyst monolith, grid, screen, gauze or the like, the conversion efficiency is preferably higher than 90%, more preferably higher than 95%. The conversion efficiency is based on the mole percentage of the particular pollutant in the air reacting in the presence of the catalyst composition.

The ozone treating catalyst composition consists of manganese dioxide including non-stoichiometric manganese dioxide (eg, MnO _(1.5-2.0) ) and / or manganese compounds comprising Mn ₂ O ₃ . Preferred manganese dioxide, nominally referred to as MnO ₂ , has a formula such that Mn ₈ O ₁₆ has a molar ratio of manganese to oxygen of about 1.5 to 2.0. Up to 100% by weight manganese dioxide MnO ₂ may be used in the ozone treating catalyst composition. Other compositions available are composed of manganese dioxide and copper oxide alone or compounds such as copper oxide and alumina.

A useful and preferred manganese dioxide is alpha manganese dioxide with a nominal manganese to oxygen molar ratio of 1-2. Useful alpha manganese dioxides are disclosed in U.S. Patent 5,340,562 to O'Young et al., And also in Oh Young's Hydrothermal Synthesis of Manganese Oxides with Tunnel Structures, August 25-30, 1991 Presented at the Symposium on Advances in Zeolites and Pillared Clay Structures. starting at p 342 and McKenzie, The Synthesis of Birnessite, Cryptomelane, and Some Other Oxides and Hydroxides of Manganese, Mineralogical Magazine, December 1971, Vol. 38, pp. 493-502. For the purpose, the preferred alpha manganese dioxide of the present invention holes randayi agent _{(BaMn 8 O 16 · xH 2} O), Cryptococcus Gamelan _{(KMn 8 O 16 · xH 2} O), maenji Detroit _{(NaMn 8 O 16 · xH 2} O) and corona die bit _{(PbMn 8 O 16 · xH 2} O) is a 2 x 2 tunnel structure which can be.

The manganese dioxide of the present invention preferably has a surface area measured by BET N ₂ adsorption than 150 m ² / g, more preferably 200 m ² / g, more preferably 225 greater than m ² / g. The upper limit of these materials can be as high as 300 m ² / g, 325 m ² / g or even 350 m ² / g. Preferred materials are in the range 200-350 m ² / g, preferably 200-275 m ² / g, most preferably 220-250 m ² / g. The composition preferably contains a binder, such as the type described below, with the preferred binder being a polymeric binder. The composition may further contain a noble metal component and the preferred noble metal component is an oxide of a precious metal, preferably an oxide of a platinum group metal and most preferably an oxide of palladium or platinum, also referred to as palladium black or platinum black. The amount of palladium or platinum black may range from 0 to 25% based on the weight of the manganese component and the precious metal component and useful amounts are about 1 to 25 and 5 to 15 weight percent.

The use of a composition containing a polymer binder, consisting of alpha manganese oxide in the form of cryptomelan, is preferably greater than 50% in an air stream traveling across the radiator at a concentration range of 0 to 400 ppb and a space velocity of 300,000 to 650,000 per hour. It has been found that it can lead to ozone conversion of preferably greater than 60%, most preferably 75-85%. Ozone conversion in this condition is in the range of 95-100% using a powder reactor when a portion of Cryptomellan is replaced with up to 25% and preferably 15-25% by weight of palladium black (PdO).

Preferred Cryptomellan manganese dioxides typically have a potassium content of 1.0 to 3.0% by weight as K ₂ O, a grain size ranging from 2 to 10 nm and preferably less than 5 nm. Is this 250 ?? To 550 ?? And preferably 500 ?? It can be calcined for at least 1.5 hours and preferably at least 2 hours up to about 6 hours in the temperature range below 300 ° C. and above.

Preferred cryptomelans can be prepared according to the abovementioned documents and as described in the patents of Oyoung and McKenzie. Cryptomellans can be made by reacting manganese salts with permanganate compounds, including salts selected from the group consisting of MnCl ₂ , Mn (NO ₃ ) ₂ , MnSO _4, and Mn (CH ₃ COO) ₂ . Cryptomellan is made using potassium permanganate, hollandite is made using barium permanganate, coronite is made using lead permanganate, and manjirite is made using sodium permanganate. It is appreciated that alpha manganese useful in the present invention may contain one or more of holandite, kryptomellan, manjirite or coronite compounds. Cryptomellans may also be present in small amounts of other metal ions, such as sodium. Useful methods for forming alpha manganese dioxide are described in the references cited above.

Preferred alpha manganese for use in accordance with the invention is cryptomellan. Preferred cryptomelans are "clean" or substantially free of inorganic anions, particularly at the surface. Such anions may include chlorine ions, sulfate ions and nitrate ions which are introduced during the process for preparing Cryptomellan. Another method of making clean cryptomellan is by reacting manganese carboxylate, preferably manganese acetate, with potassium permanganate. The use of this calcined material was found to be "clean". The use of materials containing inorganic anions can lead to a maximum of about 60% conversion of ozone to oxygen. The use of Cryptomellan with a "clean" surface results in a conversion of up to about 80%.

Carboxylic acid ions are believed to be burned off in the calcination process. However, inorganic anions remain on the surface even during the calcination process. Inorganic anions such as sulfate ions can be washed off with an aqueous solution or slightly acidic aqueous solution. Preferably the alpha manganese dioxide is a "clean" alpha manganese dioxide. Cryptomellan is about 60 ?? It can be removed for about half an hour to remove a considerable amount of sulfate anion. Washing also lowers the level of potassium ions present. Nitrate anions can be removed in a similar manner. “Clean” alpha manganese dioxide is found to have an IR spectrum as shown in FIG. 19 and an X-ray diffraction (XRD) pattern as shown in FIG. 20. Such cryptomellans preferably have a surface area greater than 200 m ² / g, more preferably greater than 250 m ² / g. Looking at the IR spectrum for the most preferred Cryptomellan shown in FIG. 19 is characterized by the absence of peaks that can be assigned to carbonic acid, sulfuric acid and nitric acid groups. The expected peak of the carbonic acid group is in the range of 1320 to 1520 frequency and the expected peak of the sulfuric acid group is in the range of 950 to 1250 frequency. FIG. 20 is a powder X-ray diffraction pattern of high surface area Cryptomellan prepared in Example 23. The X-ray pattern of cryptomellans useful in the present invention is characterized by broad peaks resulting in small grain sizes (˜5-10 nm). As shown in FIG. 20, CuK _?? The approximate peak position of Cryptomellan (x0.15 ㅀ 2 ??) and approximate relative intensity (ㅁ 5) using radiation are: 2 ?? / relative intensity-12.1 / 9, 18/9, 28.3 / 10, 37.5 / 100, 41.8 / 32, 49.7 / 16, 53.8 / 5, 60.1 / 13, 55.7 / 38 and 68.0 / 23.

A preferred process for preparing cryptomellans useful in the present invention consists in mixing an aqueous acidic manganese salt solution with a potassium permanganate solution. The acidic manganese solution preferably is made acidic using acetic acid with a pH of 0.5 to 3.0 and any common acid, preferably concentrations 0.5 to 5.0 normal and more preferably 1.0 to 2.0 normal. The mixture forms a slurry and this is 50 ?? It stirs in the temperature range of 110 to 110 degrees. The slurry was filtered and the filtrate was 75 ?? It is dried in the temperature range of 200-200 degrees. Cryptomellan crystals obtained here typically have a surface area in the range of 200 m ² / g to 350 m ² / g.

Another useful composition comprising manganese dioxide is a composition comprising a small amount of manganese biphasic and a small amount of silica, typically up to 2%, more typically up to 1%, based on the weight of manganese dioxide and silica, with preferred amounts being between 0.4 and 0.8%. to be. The presence of silica in the desired amount has been found to affect the crystalline form of manganese dioxide, especially the kryptomellan form of manganese dioxide. It is contemplated that the presence of small amounts, particularly in the preferred range of silica, may provide particular advantages to the compositions of the present invention. The presence of silica is believed to render the composition more hydrophobic, especially when used as a coating on a substrate, such as a coating on a radiator. Secondly, the presence of silica in the manganese dioxide-containing coating composition is believed to increase the pH to aid in the compatibility of the manganese dioxide and latex binder. Preferred and useful compositions for use as coatings consist of cryptomelan and silica. Such materials include cryptomelans with a surface area of 200 to 340, preferably 220 to 250 m ² / g, containing 1 to 3% by weight of potassium and less than 0.1% by weight of sulfur, mainly due to moisture 13 to 18 weight percent. The pH of the composition is about 3. Surface area is measured by the BET nitrogen adsorption and desorption test. As the amount of sulfur decreases, the pH typically increases somewhat. In addition, the pH increases with the amount of potassium present, and the preferred amount of potassium is 1.2 to 2.8% by weight.

Other useful compositions consist of one or more precious metal components, such as manganese dioxide and optionally copper oxide and alumina, and platinum group metals supported on manganese dioxide and, if present, copper oxide and alumina. Useful compositions contain up to 100% by weight, 40-80% by weight and preferably 50-70% by weight manganese dioxide and 10-60% and typically 30-50% copper oxide. Useful compositions are reported to have hopcalite having about 60% manganese dioxide and about 40% copper oxide, and carulite reported to have 60 to 75% by weight manganese dioxide, 11 to 14% copper oxide and 15 to 16% aluminum oxide. ^R 200 (available from Carus Chemical Company). It is reported that the surface area of carrullite ^R is about 180 m ² / g. Calcination at 450 ° C reduces the surface area of carulite by about 50% without severely affecting the activity. 300 Manganese Compounds ?? To 500 And more preferably 350 ?? It is preferred to calcinate at from -450 ° C. Calcination at 550 ° C. causes a large loss of surface area and ozone treatment activity. Carmelite ^R is ball milled with acetic acid and then calcined and coated onto the substrate to improve the adhesion of the coating to the substrate.

Other compositions that treat ozone may consist of a manganese dioxide component, and a precious metal component such as a platinum group metal component. While both components are catalytically active, manganese dioxide can also support the precious metal component. The platinum group metal component is preferably a palladium and / or platinum component. The amount of platinum group metal compound is preferably in the range from about 0.1 to about 10 weight percent (based on the weight of the platinum group metal) of the composition. Preferably, the amount of platinum, if present, is from 0.1 to 5% by weight, and a useful and preferred amount on the pollutant treatment catalyst volume based on the volume of the support article is from about 0.5 to about 70 g / ft ³ . The amount of palladium component is preferably in the range of about 2 to about 10 weight percent of the composition, and a useful and preferred amount on the pollutant treatment catalyst volume is in the range of about 10 to about 250 g / ft ³ .

Various useful and preferred pollutant treatment catalyst compositions, particularly those containing catalytically active components such as precious metal catalyst components, may include suitable support materials such as refractory oxide supports. Preferred refractory oxides can be selected from the group consisting of silica, alumina, titania, ceria, zirconia and chromia, and mixtures thereof. More preferably, the support is at least one activated high surface compound selected from the group consisting of alumina, silica, titania, silica-alumina, silica-zirconia, alumina silicate, alumina zirconia, alumina-chromia and alumina-ceria. Refractory oxide is typically in the form of bulk particulates having a particle size in the range of about 0.1 to about 100 and preferably in the range of 1 to 10 μm or in the form of a sol having a particle size in the range of about 1 to about 50 and preferably in the range of about 1 to about 10 nm. It may be in a suitable form including. Preferred titania sol supports consist of titania having a particle size in the range of about 1 to about 10, and typically about 2 to 5 nm.

Useful as preferred supports are co-precipitates of manganese oxide and zirconia. This composition can be made as mentioned in US Pat. No. 5,283,041, which is incorporated herein by reference. In summary, this coprecipitation support material is preferably 5:95 to 95: 5, preferably 10:90 to 75:25, more preferably 10:90 in terms of weight-based ratios of manganese and zirconium metals. To 50:50, and most preferably 15:85 to 50:50. One useful and preferred embodiment consists of a Mn: Zr weight ratio of 20:80. U.S. Patent 5,283,041 describes a preferred method of making co-precipitates of manganese oxide components and zirconia components. As mentioned in U.S. Patent No. 5,283,041, zirconia oxide and manganese oxide materials include manganese nitrate, manganese acetate, phosphate and an aqueous solution of a suitable zirconium oxide precursor such as zirconium oxynitrate, zirconium acetate, zirconium oxychloride or zirconium oxysulfate. Mix appropriate manganese oxide precursors such as manganese or manganese dibromide, add a base such as ammonium hydroxide in an amount sufficient to reach pH 8-9, filter the resulting precipitate, wash with water and It can manufacture by drying at -500 '.

Useful supports for ozone treating catalysts are selected from refractory oxide supports, preferably alumina and silica-alumina, and more preferred supports are silica-alumina consisting of about 1 to 10 wt% silica and 90 to 99 wt% alumina. It is a support.

Refractory oxide supports useful in catalysts consisting of platinum group metals for treating carbon monoxide are selected from alumina, titania, silica-zirconia and manganese-zirconia. Preferred supports for the catalyst composition for treating carbon monoxide are zirconia-silica supports such as those mentioned in US Pat. No. 5,145,825, manganese-zirconia supports such as those mentioned in US Pat. No. 5,283,041 and high surface area alumina. Most preferred for the treatment of carbon monoxide is titania. Reduced catalysts with titania supports have higher carbon monoxide conversions than the corresponding non-reducing catalysts.

Support for catalysts for treating low molecular weight hydrocarbons, especially hydrocarbons such as low molecular weight olefinic hydrocarbons having about 2 to about 20 carbon atoms and typically having 2 to about 8 carbon atoms, as well as partially oxygenated hydrocarbons Is preferably selected from refractory metal oxides including alumina and titania. As in the case of catalysts for treating carbon monoxide, reduced catalysts lead to higher hydrocarbon conversions. Particularly preferred are titania supports that have been found to be useful as they result in catalyst compositions showing improved ozone conversion as well as significant conversions of carbon monoxide and low molecular weight olefins. The surface area is greater than 150 m ² / g and is preferably in the range of about 150 to 350, preferably 200 to 300, and more preferably 225 to 275 m ² / g, with a porosity of 0.5 based on mercury porosimetry. High surface area, porous refractory oxides, preferably alumina and titania, which are larger than cc / g and typically range from 0.5 to 4.0 and preferably from about 1 to 2 cc / g and particle sizes from 0.1 to 10 μm, are also useful. Do. One useful material is Versal GL alumina, having a surface area of about 260 m ² / g, a porosity of 1.4 to 1.5 cc / g and supplied by LaRoche Industries.

A preferred refractory support for platinum group metals, preferably platinum and / or palladium, used to treat carbon monoxide and / or hydrocarbons is titania. Tania is available in bulk powder form or in titania dioxide sol form. Nanoparticle size (nm) titania is also useful. The catalyst composition may be prepared by adding the platinum group metal in a liquid medium, preferably in the form of a solution such as platinum nitrate and titania sol, with sol being most preferred. The resulting slurry can then be coated onto a suitable substrate, such as an atmospheric treatment surface such as a radiator, a metal monolithic substrate or a ceramic substrate. Preferred platinum group metals are platinum compounds. The platinum titania sol catalyst obtained in the above process has high activity against carbon monoxide and / or hydrocarbon oxidation at ambient operating temperatures. Metallic components other than the platinum component that may be combined with titania sol include the gold, palladium, rhodium, silver components and mixtures thereof. Reduced platinum group components, preferably platinum component catalysts on titanium, which are indicated as being preferred for treating carbon monoxide, have been found to be useful and preferred for treating hydrocarbons, in particular olefinic hydrocarbons.

Preferred titania sol supports consist of titania having a particle size in the range of about 1 to about 10, and typically about 2 to 5 nm.

Preferred bulk titania has a surface area of about 25 to 120 m ² / g, and preferably 50 to 100 m ² / g and a particle size of about 0.1 to 10 μm. One particular and preferred bulk titania support has a surface area of 45-50 m ² / g, a particle size of about 1 μm and is sold as P-25 at DeGussa. Useful nanoparticle size titanium consists of particles having a particle size of about 5 to 100 nm, typically 10 to about 50 nm.

Preferred silica-zirconia supports consist of 1 to 10% silica and 90 to 99% zirconia. Preferred support particles are for example 100 to 500 m ² / g, preferably 150 to 450 m ² / g, more preferably 200 to 400 m ² / to enhance the dispersion of the catalytic metal component or components thereon. Large surface area in g. Preferred refractory metal oxide supports also have high porosities, for example about 0.75 to 1.5 cm ³ / g, preferably about 0.9 to 1.2 cm ³ / g, with pores having a radius of up to about 145 nm, and about porosity. At least 50% has a pore size range provided by pores with a radius of 5 to 100 nm.

Useful ozonation catalysts consist of one or more precious metal components, preferably palladium components, dispersed on a suitable support, such as a refractory oxide support. The composition contains from 0.1 to 20.0% by weight, and preferably from 0.5 to 15% by weight, of precious metals (metals other than oxides) and on a support such as a refractory oxide support, based on the weight of the support. Palladium is preferably used in an amount of 2 to 15% by weight, more preferably 5 to 15% by weight, even more preferably 8 to 12% by weight. Platinum is preferably used at 0.1 to 10% by weight, more preferably at 0.1 to 5.0% by weight, even more preferably at 2 to 5% by weight. Palladium is most preferred for catalyzing the reaction that ozone forms oxygen. The support material can be selected from the groups listed above. In a preferred embodiment, there may additionally be a bulk manganese component as mentioned above, or a manganese component dispersed on a refractory oxide support that is the same or different than the precious metal, preferably the palladium component. In the pollutant treating composition up to 80% by weight, preferably up to 50% by weight, more preferably 1 to 40% by weight and even more preferably 5 to 35% by weight, based on the weight of palladium and manganese metal, There may be. In other words, there is preferably about 2 to 30% by weight and preferably 2 to 10% by weight of manganese components. The catalyst load is 20 to 250 g and preferably about 50 to 250 g of palladium per cubic foot of catalyst volume. The catalyst volume is the total volume of the finished catalyst composition and thus comprises the total volume of the air conditioner condenser or radiator including the void space provided by the airflow passage. In general, a higher load of palladium results in a higher ozone conversion, i.e. a higher percentage of ozone decomposition in the treated air stream.

About 40 ?? The conversion of ozone to oxygen obtained with the use of a palladium / manganese catalyst composition on an alumina support at temperatures of from 50 to 50 ° was about 50 mol% with ozone concentrations ranging from 0.1 to 0.4 ppm and face speeds of about 10 miles per hour . Lower conversions were obtained using platinum catalysts on alumina.

Of particular note is the use of a support consisting of the coprecipitated product of manganese oxide and zirconia described above, which is preferably used to support precious metals selected from platinum and palladium, most preferably platinum. Platinum is of particular interest as it has been found that platinum is particularly effective when used on this co-precipitated support. The amount of platinum can range from 0.1 to 6% by weight, preferably from 0.5 to 4% by weight, more preferably from 1 to 4% by weight, and most preferably from 2 to 4% by weight, based on the support co-precipitated with the metal platinum. have. The use of platinum to treat ozone has been found to be particularly effective on this support. In addition, as discussed below, this catalyst is useful for treating carbon monoxide. Preferably the noble metal is platinum and the catalyst is reduced.

Other useful catalysts for catalytically converting ozone to oxygen are described in US Pat. Nos. 4,343,776 and 4,405,507, which are incorporated herein by reference. US Patent Application No. 08 / 202,397, filed February 25, 1994 and now entitled US Patent No. 5,422,331, useful and most preferred compositions, incorporated herein by reference, named "Light Weight, Low" Pressure Drop Ozone Decomposition Catalyst for Aircraft Applications. Another composition that can lead to the conversion of ozone to oxygen consists of carbon and palladium or platinum, manganese dioxide, carulite ^R , and / or hopcalite supported on carbon. Manganese supported on refractory oxides such as those listed above has also been found to be useful.

The carbon monoxide treatment catalyst preferably consists of at least one precious metal component selected from platinum and / or palladium components, most preferably the platinum component. Combining the platinum and palladium components improves the CO conversion with increasing cost, and the combination of the platinum and palladium components is most desirable when a higher conversion is desired and an increase in cost is acceptable. The composition contains from 0.01 to 20% by weight, and preferably from 0.5 to 15% by weight, of the precious metal component on a suitable support, such as a refractory oxide support, wherein the amount of the precious metal is based on the weight of the precious metal (metal component and nonmetal component) and the support. do. Platinum is most preferred and is preferably used in amounts of 0.01 to 10% by weight, more preferably 0.1 to 5% by weight and most preferably 1.0 to 5.0% by weight. Palladium is useful in amounts of 2-15% by weight, preferably 5-15% by weight, even more preferably 8-12% by weight. Preferred support is titania, with titania sol most preferred as listed above. When loaded onto a monolithic structure, such as a radiator, or other atmospheric contact surfaces, the catalyst load is preferably about 1 to 150 g, and more preferably 10 to 100 g of platinum and / or per cubic foot of catalyst volume. 20 to 250 g and preferably 50 to 250 g of palladium per cubic foot of catalyst volume. When used in combination of palladium and platinum, platinum is about 25-100 g / ft ³ and palladium is 50-250 g / ft ³ . Preferred compositions consist of about 50 to 90 g / ft ³ of platinum and 100 to 225 g / ft ³ of palladium. Preferred catalysts are reduced. 25 ?? for a carbon monoxide concentration of 15 to 25 ppm and a space velocity of 300,000 to 500,000 per hour Conversion rates of carbon monoxide to carbon dioxide of 5 to 80 mole% were obtained using coated core samples from automotive radiators with platinum compositions of 1 to 6% by weight (based on metals) on titania at temperatures from 90 ° to 90 °. Also, if the carbon monoxide concentration is about 15 ppm and the space velocity is about 300,000 per hour, about 95 ?? Conversion rates of carbon monoxide to carbon dioxide of 5 to 65 mol% were obtained using 1.5 to 4.0 wt% platinum composition on the alumina support at the following temperatures. Lower conversions were obtained with palladium on the ceria support.

Another preferred catalyst composition for treating carbon monoxide consists of a noble metal component supported on the co-precipitates of manganese oxide and zirconia described above. Coprecipitates are formed as described above. Preferred ratios of manganese to zirconia are 5:95 to 95: 5, 10:90 to 75:25, 10:90 to 50:50, and 15:85 to 25:75 and the preferred coprecipitate has a manganese oxide to zirconia of 20 : 80. The percentage of platinum supported on the coprecipitate based on the platinum metal is 0.1 to 6% by weight, preferably 0.5 to 4% by weight, more preferably 1 to 4% by weight, and most preferably 2-4% by weight. % Range. Preferably the catalyst is reduced. The catalyst can be reduced in powder form or after coating on a support substrate. Other useful compositions that can convert carbon monoxide to carbon dioxide include a platinum component supported on a support made of carbon or manganese dioxide.

Treat hydrocarbons, typically unsaturated hydrocarbons, more typically unsaturated mono-olefins having 2 to about 20 carbon atoms and especially 2 to 8 carbon atoms, and partially oxygenated hydrocarbons of the kind mentioned above The catalyst is preferably composed of at least one precious metal component selected from platinum and palladium components, most preferably platinum component. Combining the platinum component and the palladium component improves hydrocarbon conversions at an increased cost, and the combination of the platinum component and the palladium component is most desirable when a higher conversion rate is desired and an increase in cost can be tolerated. Useful catalyst compositions include those described for use in treating carbon monoxide. The composition for treating hydrocarbons contains from 0.01 to 20% by weight, and preferably from 0.5 to 15% by weight, of a precious metal component on a suitable support, such as a refractory oxide support, and the amount of the precious metal is from the precious metal (not the metal component) and the support. Based on weight. Platinum is most preferred and is preferably used in amounts of 0.01 to 10% by weight, more preferably 0.1 to 5% by weight and most preferably 1.0 to 5% by weight. When loaded onto a monolithic structure, such as a motor vehicle radiator, or on other atmospheric contact surfaces, the catalyst load is preferably about 1 to 150 g, and more preferably 10 to 100 g of platinum per cubic foot of catalyst volume. When used in combination of palladium and platinum, platinum is about 25-100 g / ft ³ and palladium is 50-250 g / ft ³ . Preferred compositions consist of about 50 to 90 g / ft ³ of platinum and 100 to 225 g / ft ³ of palladium. Preferred refractory oxide supports are alumina and titania being the most preferred metal oxide refractory materials, preferably selected from ceria, silica, zirconia, alumina, titania and mixtures thereof. Preferred titania are characterized by those listed above, with titania sol being most preferred. Preferred catalysts are reduced. When tested in coated automotive radiators, water and low molecular weight mono-olefins such as propylene with 1.5 to 4% by weight of platinum on alumina or titania supports have a propylene concentration of about 10 ppm and a space velocity of about 320,000 per hour. The conversion to carbon dioxide was between 15 and 25%. These catalysts were not reduced. Reduction of the catalyst improves the conversion rate.

Catalysts useful for the oxidation of both carbon monoxide and hydrocarbons generally include those listed above as useful for treating either carbon monoxide or hydrocarbons. The most preferred catalyst found to have good activity in the treatment of both hydrocarbons such as carbon monoxide and unsaturated olefins consists of the platinum component supported on the preferred titania support. This composition preferably contains a binder and may be coated in an amount of 0.8 to 1.0 g / in on a suitable support structure. Preferred platinum concentrations range from 2 to 6% by weight and preferably from 3 to 5% by weight of the platinum metal on the titania support. Useful and preferred substrate cell densities correspond to about 300 to 400 cells per square inch. The catalyst is reduced on a coated or reduced article, preferably as a powder using a suitable reducing agent. Preferably, the catalyst is selected from 200 ?? in a gas stream consisting of about 7% hydrogen and the remaining nitrogen. To 500 ?? or for 1 to 12 hours. The most preferred reduction or formation temperature is for 2-6 hours at 400 ??. The catalyst has been found to maintain high activity in air and wet air at elevated temperatures of up to 100 ° after prolonged exposure.

Useful catalysts capable of treating both ozone and carbon monoxide consist of one or more precious metal components on a suitable support, such as refractory oxide supports, most preferably precious metals selected from palladium, platinum and mixtures thereof. Combining the platinum component with the palladium component improves the CO conversion with increasing cost, and the combination of the platinum component with the palladium component is most desirable when a higher conversion is desired and an increase in cost can be tolerated. Useful refractory oxide supports consist of ceria, zirconia, alumina, titania, silica and mixtures thereof, as well as mixtures of zirconia and silica as described above. Also useful and preferred as a support is the coprecipitation of manganese oxide and zirconia described above. The composition contains 0.1 to 20.0% by weight, preferably 0.5 to 15% by weight, and more preferably 1 to 10% by weight of the precious metal component on the support based on the weight of the precious metal and the support. Palladium is preferably used in amounts of 2 to 15% by weight and more preferably 3 to 8% by weight. Platinum is preferably used in amounts of 0.1 to 6% by weight and more preferably 2 to 5% by weight. Preferred compositions are compositions wherein the refractory component consists of ceria and the precious metal component consists of palladium. This composition resulted in a relatively high ozone and carbon monoxide conversion. More specifically, the carbon monoxide conversion of 21% in an air stream containing 16 ppm of carbon monoxide, when the composition was tested on a coated radiator, contacted the surface of 95 ?? with a gas stream face velocity of 5 miles per hour Obtained. This same catalyst resulted in an ozone conversion of 55% when the stream contained 0.25 ppm ozone, the treated surface was 25 ?? and the air stream face velocity was 10 miles per hour. Also preferred are compositions selected from precious metals, preferably platinum group metals, more preferably platinum and palladium components, most preferably consisting of platinum components and co-precipitates of the manganese oxides and zirconia mentioned above. This aforementioned noble metal containing catalyst in the form of a catalyst powder or coating on a suitable support is in reduced form. Preferred reducing conditions include those mentioned above, the most preferred being 250 ° C. for 2-4 hours in a reducing gas consisting of 7% hydrogen and 93% nitrogen. To 350 ?? This catalyst has been found to be particularly useful for treating both carbon monoxide and ozone. Other useful compositions for converting ozone to oxygen and carbon monoxide to carbon dioxide consist of platinum components supported on carbon, manganese dioxide, or refractory oxide supports and optionally have additional manganese components.

Useful and preferred catalysts capable of treating ozone, carbon monoxide and hydrocarbons, as well as partially oxygenated hydrocarbons, consist of noble metal components, preferably platinum components, on suitable supports such as refractory oxide supports. Combining the platinum component with the palladium component improves the CO conversion with increasing cost, and the combination of the platinum component with the palladium component is most desirable when a higher conversion is desired and an increase in cost can be tolerated. Useful refractory oxide supports consist of ceria, zirconia, alumina, titania, silica and mixtures thereof, as well as mixtures of zirconia and silica as described above. Supports including co-precipitates of manganese oxide and zirconia described above are also useful. The composition contains from 0.1 to 20% by weight, preferably from 0.5 to 15% by weight, and more preferably from 1 to 10% by weight of the precious metal component on the refractory support based on the weight of the precious metal and the support. In the case of converting hydrocarbon components into carbon dioxide and water, platinum is the most preferred catalyst and is preferably used in an amount of 0.1 to 5% by weight, and more preferably 2 to 5% by weight.

In particular embodiments, there may be a combination of catalysts comprising catalysts particularly preferred for the treatment of ozone, such as those consisting of manganese components as well as the catalysts listed above. The manganese component may optionally be combined with the platinum component. Manganese and platinum may be on the same or different supports. The pollutant treating composition may contain up to 80% by weight, preferably up to 50% by weight, more preferably 1 to 40% by weight and even more preferably 10 to 35% by weight, based on the weight of the precious metal and manganese. Can be. The catalyst load is the same as mentioned above in connection with the ozone catalyst. Preferred compositions are compositions wherein the refractory component consists of an alumina or titania support and the precious metal component consists of a platinum component. When testing this composition coated on a radiator, the gas stream contacted the surface of 95 ° with a plane velocity of about 10 miles per hour (space velocity per hour 320,000 per hour) and an air dew point of 35 °. In this case, the carbon monoxide conversion was 68 to 72%, the ozone conversion was 8 to 15%, and the propylene conversion was 17 to 18%. In general, the conversion percentage decreases as the contact surface temperature decreases and the space velocity or face velocity of the airflow through the pollutant contact surface increases.

The catalytic activity, particularly the catalytic activity of treating carbon monoxide and hydrocarbons, can be further enhanced by reducing the catalyst in forming gas such as hydrogen, carbon monoxide, methane or hydrocarbons plus nitrogen gas. Alternatively, the reducing agent may be in liquid form, such as formate, such as hydrazine, formic acid, and sodium formate solution. The catalyst can be reduced in powder state or after coating on the substrate. Reduction is 150 ?? To 500 ??, preferably 200 ?? It can be carried out for 1 to 12 hours, preferably 2 to 8 hours in a gas of from 400 to 400 ℃. In a preferred method, the coated product or powder is treated with 275 ?? Can be reduced for 2 to 4 hours in a gas consisting of 7% hydrogen in nitrogen.

Another type of composition for use in the method and apparatus of the present invention is a catalytically active material selected from the group consisting of a noble metal component including a platinum group metal component, a gold component and a silver component and a metal component selected from the group consisting of a tungsten component and a rhenium component Is done. The relative amounts of catalytically active material to tungsten component and / or rhenium component based on the weight of the metal are 1-25 to 15-1.

The composition containing the tungsten component and / or rhenium component preferably contains tungsten and / or rhenium in oxide form. This oxide can be obtained by forming the composition using tungsten or rhenium salt and the composition can subsequently be calcined to form tungsten and / or rhenium oxide. The composition may contain additional components such as a refractory oxide support, a manganese component, carbon, and a support comprising a co-precipitate of manganese oxide and zirconia. Useful refractory metal oxides include alumina, silica, titania, ceria, zirconia, chromia and mixtures thereof. The composition may further contain a binder material, such as a polymer binder, which may be provided in the form of a metal sol or polymer latex binder, including alumina or titania sol.

In a preferred composition there is from 0.5 to 15% by weight, preferably from 1 to 10% by weight, and most preferably from 3 to 5% by weight of the catalytically active material. Preferred catalytically active materials are platinum group metals, platinum and palladium are more preferred and platinum is most preferred. The amount of tungsten and / or rhenium component based on the metal ranges from 1 to 25% by weight, preferably from 2 to 15% by weight and most preferably from 3 to 10% by weight. The amount of binder may vary between 0 and 20% by weight, preferably between 0.5 and 20% by weight, more preferably between 2 and 10% by weight and most preferably between 2 and 5% by weight. Depending on the support material, no binder is required in this composition. Preferred compositions consist of 60 to 98.5 wt% refractory oxide support, 0.5 to 15 wt% catalytically active material, 1 to 25 wt% tungsten and / or rhenium component, and 0 to 10 wt% binder.

The composition comprising the tungsten component and the rhenium component can be calcined under the conditions as mentioned above. In addition, the composition may be reduced. However, as shown in the examples below, there is no need to reduce the composition and the presence of tungsten and / or rhenium components can make it comparable to compositions containing platinum group metals, with reduced conversions of carbon monoxide and hydrocarbons.

The pollutant treating composition of the present invention preferably contains a binder that acts to bond the composition and provide adhesion to the atmospheric contact surface. Preferred binders have been found to be polymeric binders used in amounts of 0.5 to 20% by weight, more preferably 2 to 10% by weight, and most preferably 2 to 5% by weight, based on the weight of the composition. Preferably, the binder is a polymeric binder, which may be a thermosetting or thermoplastic polymer binder. The polymeric binder may have suitable stabilizers and anti-aging agents known in the polymer art. This polymer may be a plastic or elastomeric polymer. Most preferred are thermoset, elastomeric polymers which are introduced into the catalyst composition slurry as a latex, preferably into the aqueous slurry. Upon application and heating of the composition, the binder material may crosslink to provide a suitable support that enhances the integrity of the coating, adhesion to the atmospheric contact surface and provides structural stability under vibrations that may be encountered in a motor vehicle. The use of a preferred polymeric binder allows the pollutant treating composition to adhere to the atmospheric contact surface without the need for an undercoat. The binder may be made of a waterproof adhesive to improve waterproofness and enhance adhesion. Such adhesives may include fluorocarbon emulsions and petroleum wax emulsions.

Useful polymer compositions include polyethylene, polypropylene, polyolefin copolymers, polyisoprene, polybutadiene, polybutadiene copolymers, chlorinated rubber, nitrile rubber, polychloroprene, ethylene-propylene-diene elastomers, polystyrene, polyacrylates, polymethacrylates , Polyacrylonitrile, poly (vinyl ester), poly (vinyl halide), polyamide, cellulose polymer, polyimide, acrylic resin, vinyl acrylic resin and styrene acrylic resin, polyvinyl alcohol, thermoplastic polyester, thermosetting polyester Fluorinated polymers such as poly (phenylene oxide), poly (phenylene sulfide), poly (tetrafluoroethylene), polyvinylidene fluoride, poly (vinylfluoride), and ethylene chlorotrifluoroethylene air Chloro / fluoro copolymers such as copolymers, polyamides, phenolic resins And epoxy resins, polyurethanes and silicone polymers. Most preferred polymer material is an acrylic polymer latex as described in the accompanying examples.

Particularly preferred polymers and copolymers are vinyl acrylic polymers and ethylene vinyl acetate copolymers. One preferred vinyl acrylic polymer is a crosslinked polymer sold by National Starch and Chemical Company as Xlink 2833. This is explained by a vinyl acrylic polymer having a Tg of -15 ??, a solid content of 45%, a pH of 4.5 and a viscosity of 300 cps. In particular, this is vinyl acetate CAS No. 108-05-4 is indicated to have a concentration range of less than 0.5%. It is indicated to be a vinyl acetate copolymer. Other preferred vinyl acetate copolymers sold by National Starch and Chemical Company include Dur-O-Set E-623 and Dur-O-Set E-646. Dur-O-Set E-623 is indicated as an ethylene vinyl acetate copolymer having a Tg of 0 ??, 52% solids, a pH of 5.5 and a viscosity of 200 cps. Dur-O-Set E-646 is indicated as an ethylene vinyl acetate copolymer having a Tg of -12 ??, 52% solids, a pH of 5.5 and a viscosity of 300 cps. Useful and preferred binders are crosslinked acrylic copolymers marketed as X-4280 by National Starch and Chemical Company. It is described as a milky white emulsion having a pH of 2.6, a boiling point of 212 ° C, a freezing point of 32 ° C, a specific gravity of 1.060 and a viscosity of 100 cps.

Another useful binding material is the use of zirconium compounds. Zirconyl acetate is the preferred zirconium compound used. Zirconia is believed to act as a high temperature stabilizer, enhance catalyst activity and improve catalyst adhesion. Upon calcination, zirconium compounds such as zirconyl acetate are converted to ZrO ₂ which is believed to be a binding material. Various useful zirconium compounds for producing ZrO ₂ in the catalyst include acetates, hydroxides, nitrates and the like. When zirconyl acetate is used as the binder in the catalyst of the present invention, ZrO ₂ will not be formed unless the radiator coating is calcined. Since good adhesion has been obtained at a "calcination" temperature of only 120 ° C, zirconyl acetate does not decompose into zirconium oxide but instead crosslinks with acetates formed in ball milling using acetic acid and pollutant treatment materials such as carulite ^R particles. It is believed to have formed a mesh. Thus, the use of zirconium-containing compounds in the catalyst of the present invention is not limited to zirconia alone. In addition, zirconium compounds can be used with other binders, such as the polymeric binders described above.

Other pollutant treatment catalyst compositions may consist of activated carbon compositions. The carbon composition consists of conventional additives such as activated carbon, binders such as polymeric binders, and optionally antifoams. Useful activated carbon compositions consist of 75 to 85% by weight of an antifoaming agent, such as activated carbon such as "coconut rind" carbon or carbon from wood and binders such as acrylic binders. Useful slurries contain 10 to 50 weight percent solids. Activated carbon not only catalyzes the reduction of ozone to oxygen, but also can adsorb other pollutants.

The pollutant treating catalyst composition of the present invention may be prepared by any suitable method. One preferred method is disclosed in US Pat. No. 4,134,860, which is incorporated herein by reference. According to this method, refractory oxide supports such as activated alumina, titania or activated silica alumina are jet milled and impregnated with a catalyst metal salt, preferably a noble metal salt solution, followed by an appropriate temperature, typically about 300 ° C. To about 600 ??, preferably about 350 ?? To about 550 ??, and more preferably about 400 ?? Calcining for from about 0.5 to about 12 hours. The palladium salt is preferably palladium amine, such as palladium nitrate or palladium tetraamine acetate or palladium tetraamine hydroxide. Platinum salts preferably include platinum hydroxide dissolved in amines. In a particular and preferred embodiment, the calcined catalyst is reduced as described above.

Manganese salts such as manganese nitrate in the ozone treatment composition can be mixed with alumina supported palladium dried and calcined in the presence of deionized water. The amount of water added should be at the initial wetting point. See the method reviewed in US Pat. No. 4,134,860, supra. The initial wet point is the point at which the amount of liquid added is the lowest concentration at which the powdery mixture is sufficiently dry to absorb substantially all of the liquid. In this way soluble manganese salts such as Mn (NO ₃ ) _{2 in} water can be added to the calcined supported catalyst noble metal. The mixture is then dried and calcined for about 0.5 to about 12 hours at an appropriate temperature, preferably 400 to 500 °.

Alternatively, the supported catalyst powder (ie, palladium supported on alumina) may be combined with a liquid, preferably water, to form a slurry to which a solution of manganese salt such as Mn (NO ₃ ) ₂ is applied. Preferably, the manganese component and the palladium supported on the refractory support such as activated alumina, more preferably activated silica-alumina, are mixed with an appropriate amount of water to have a solid content of 15 to 40% by weight and preferably 20 to 35% by weight. Causes phosphorus slurry to be produced. The combined mixture is coated on a carrier such as a radiator and the radiator is 50 ?? Dry in air for 1 to 12 hours under suitable conditions such as from 150 ° to 150 °. The substrate supporting the coating was then placed in an oven, typically 300 To 550 ??, preferably 350 ?? To 500 ??, more preferably 350 ?? To 450 ?? And most preferably 400 ?? To about 500 to about 12 hours in an oxygen-containing atmosphere, preferably air, at suitable conditions of from -500 ° C to help calcinate the components and fix the coating to the substrate atmospheric contact surface. If the composition further contains a precious metal component, it is preferably reduced after calcination.

The process of the present invention comprises forming a mixture of water with a catalytically active material selected from one or more platinum group metal components, gold components, silver components, manganese components and mixtures thereof. The catalytically active material may be on a suitable support, preferably on a refractory oxide support. When using precious metal catalyst materials the mixture can be milled, calcined and optionally reduced. The calcination step can be performed prior to the polymer binder milling and addition. It is also desirable to reduce the catalytically active material before milling, calcining and adding the polymeric binder. The slurry comprises an amount such that the pH of the polymer or derivative thereof containing the carboxylic acid compound or carboxylic acid group is about 3 to 7, typically 3 to 6. Preferably the acid contains from 0.5 to 15% by weight glacial acetic acid based on the weight of the catalytically active material and acetic acid. The amount of water can be added as appropriate to obtain a slurry of the desired viscosity and solids concentration. Solids percentage is typically 20 to 50% by weight and preferably 30 to 40% by weight. Preferred vehicles are deionized water (D.I.). Acetic acid can form and add a mixture of water and catalytically active material that may have already been calcined. Alternatively, acetic acid can be added with the polymer binder. A preferred composition for treating ozone using manganese dioxide as a catalyst can be made using about 1,500 g of manganese dioxide mixed with 2,250 g of deionized water and 75 g of acetic acid. The mixture is combined in a 1 gallon ball mill and ball milled for about 8 hours until approximately 90% of the particles are less than 8 μm. Empty the ball mill and add 150 g of polymer binder. The mixture is then compounded in a roll mill for 30 minutes. The mixture obtained here is ready to be coated on a suitable substrate such as a car radiator according to the method described below.

It has been found that the compatibility of slurry components, including catalyst materials and polymeric binders such as latex emulsions, is desirable to keep the slurry stable and uniform. For the purposes of the present invention, compatibility means that the binder and catalyst material remain in the mixture of separate particles in the slurry. It is believed that when the polymeric binder is a latex emulsion and the charges that cause the catalytic materials to repel each other are compatible and the slurry is stable, the catalyst material and the polymer latex are uniformly distributed in an aqueous fluid such as a liquid vehicle, for example water. If the catalyst material and the latex emulsion particles do not repel each other, irreversible aggregation of the latex on the catalyst material will occur. The materials are therefore incompatible and the latex escapes the emulsion.

The compatibility of high surface area catalysts with organic latex binders is key to the production of stable, uniform slurries. If the catalyst and latex emulsion particles do not repel each other, irreversible agglomeration will occur. This will result in unstable, non-uniform slurries that will produce poor adhesion coatings. Although the mutual repulsion of the catalyst and binder particles is controlled by various physical factors, surface charge plays a key role. Since the latex emulsion particles are typically charged with anions, the catalyst particles must be charged with numbers. However, zeta potential measurements indicate that catalyst particles, such as MnO ₂ , are only slightly negatively charged, or even positively charged, as a result of which irreversible aggregation of the catalyst and latex occurs (ie, the catalyst and latex are commercially available). No surname). Although the aforementioned method of adding acetic acid provides certain advantages, such as viscosity control, to the slurry of the present invention, it has been found that this does not enhance compatibility and may even be detrimental to aging slurry stability.

If the catalytic material is charged with cations or slightly anions, compatibility can be improved by making the slurry more basic. The pH of the slurry can be adjusted according to the acidity of the catalyst material and the preferred pH level is at least 6, preferably at least 7 and more preferably at least 8.5. In general, the slurry should not be too caustic and the preferred upper limit is about 11. The preferred range is 8.5-11.

It is critical to keep the pH of the slurry consisting of latex emulsion and MnO ₂ (cryptomelan) above 8.5. If the pH falls below 8.5 for an extended number of days, the binder and catalyst will irreversibly aggregate. Despite the large negative charge on the cryptomelan particles at this pH, the long term stability of the cryptomelan containing slurry was difficult to achieve. Preferred binders are binders based on poly (acrylic) acid derivatives, and particularly preferred binders with long term stability under these conditions are acrylic latexes sold as x-4280 acrylic latexes at National Starch. It is difficult to achieve long-term compatibility with basic slurries containing anionic latex and catalyst particles, indicating that even if surface charge is important, surface charge is not the only factor in determining binder / catalyst compatibility. . Other factors that play a role include emulsion particle size, surfactant packages, and the like. The method includes raising the pH of the ball milling catalyst slurry to at least 8.5, preferably at least 9 to enhance stability.

Another method of increasing slurry stability involves adding a surfactant, such as a polymer dispersant, to the slurry in addition to or instead of increasing the pH. In the second case, binder / catalyst compatibility is achieved by adding polymeric acrylate derived dispersants (particularly on a 3% solids basis) instead of increasing the pH. However, the results are the same in that the catalyst particles are provided with large negative charges that can repel equally charged latex particles. Dispersants may be added during or after the ball milling process. Despite the generation of large negative charges on the catalyst particles, in addition, all dispersants do not behave the same. Preferred dispersants consist of polymers containing derivatives thereof, such as carboxylic acid groups or ester salts. Preferred dispersants include Accucus 445 (manufactured by Rohm & Haas) and colloid 226/35 (manufactured by Rhino-Poulenc). A review of useful dispersants and dispersing techniques is presented in Additives for Dispersion, Rhone-Poulenc, Surfactants & Specialty, which is incorporated herein by reference. Useful polymer dispersants include, but are not limited to, polyacrylic acid partial sodium salts and anionic co-complex sodium salts sold by Rhone-Poulenc as colloid ^™ polymer dispersants. In other words, although surface charge is an important factor in determining catalyst / binder compatibility, it is not the only factor. In general, dispersants (particularly colloid 226) do a good job of stabilizing the slurry because most types of latex binders (eg, acrylic resins, styrene acrylic resins, and EVA) are compatible. Long term compatibility problems can be addressed by increasing the amount of dispersant, raising the pH to some extent, or both.

The process described above increases compatibility and results in a stable catalyst slurry. Both methods produce large surface negative charges on the catalyst particles and then stabilize the catalyst in the presence of equally charged (anion) latex emulsion particles. For both systems, good adhesion was observed at 10 wt% load (based on solids) of the polymer binder (ie, the catalyst could not strip off the side of the coating monolith). At 5%, the adhesion is not good and the optimal load is preferably in either case.

While the above methods have been shown to increase the compatibility of MnO ₂ / latex slurries, the present invention is not limited to systems using an anion charged latex emulsion. Those skilled in the art will likewise appreciate that slurry compatibility can be achieved using cationic surfactants and / or dispersant packages using cationic latex emulsions to stabilize catalyst particles.

Current polymer slurries, particularly polymer latex slurries, may include conventional additives such as thickeners, biocides, antioxidants, and the like.

The pollutant treating composition may be applied to the atmospheric contact surface by any suitable means, such as spray coating, powder coating, or brushing or dipping the surface into and out of the catalyst slurry.

The atmospheric contact surface is preferably cleaned to remove surface dirt, especially oils that may result in poor adhesion of the pollutant treating composition to the surface. Where possible, it is desirable to heat the substrate on which the surface is located to a temperature high enough to volatilize or burn the surface dirt and oil.

If a substrate with an atmospheric contact surface is made of a material that can withstand elevated temperatures, such as an aluminum radiator, the substrate surface is treated in a manner that enhances adhesion to the catalyst composition, preferably ozone, carbon monoxide and / or hydrocarbons catalyst composition. can do. One method is to heat an aluminum substrate, such as a radiator, for a sufficient time in air to a temperature sufficient to form a thin layer of aluminum oxide on the surface. This helps to clean the surface by removing oil that may interfere with adhesion. Further, if the surface is aluminum, the radiator is placed at 350 ° C. for 0.5 to 24 hours, preferably 8 to 24 hours and more preferably 12 to 20 hours in air. To 500 ??, preferably 400 to 500 ?? And more preferably 425 ?? It has been found that a sufficient layer of oxidized aluminum can be formed by heating to from 475 ° to 475 °. In some cases, sufficient adhesion was obtained without using an undercoat layer when the aluminum radiator was heated in air at 450 ° C. for 16 hours. This method is particularly useful when applying a coating before a new surface, such as a radiator or air conditioner condenser, is assembled in a motor vehicle as an original part or replacement.

Adhesion can be improved by applying undercoat or precoating to the substrate. Useful undercoats or precoats include refractory oxide supports of the kind discussed above, with alumina being preferred. Preference for increasing the adhesion between the atmospheric contact surface and the top coat of the ozone catalyst composition is described in commonly assigned U. S. Patent No. 5,422, 331, which is incorporated herein by reference. The undercoat is disclosed to consist of a mixture of fine particulate refractory metal oxides and sol selected from silica, alumina, zirconia and titania sol. According to the method of the present invention, surfaces in existing vehicles can be coated with substrates such as radiators, radiator fans or air conditioner condensers positioned in the vehicle. The catalyst composition can be applied directly to the surface. If more adhesion is desired, the undercoat can be used as mentioned above.

If it is practical to separate the radiator from the vehicle, support materials such as activated alumina, silica-alumina, bulk titania, titanium sol, silica zirconia, manganese zirconia and others mentioned are formed into a slurry and preferably together with the silica sol Coating on the substrate can improve the adhesion. The precoated substrate may subsequently be coated with soluble noble metal salts, such as platinum and / or palladium salts and optionally manganese nitrate. The coated substrate may then be heated in air for a time (0.5-12 hours at 350'-550 ') to calcinate the palladium and manganese components in an oven to form their oxides.

The present invention may consist of an adsorption composition supported on an atmospheric contact surface. The adsorption composition can be used to adsorb particulate matter such as particulate hydrocarbons, soot, pollen, bacteria and germs as well as gaseous pollutants such as hydrocarbons and sulfur dioxide. Useful supported compositions can adsorb hydrocarbons, including adsorbents such as zeolites. Useful zeolite compositions are described in International Patent Publication No. 94/27709, entitled "Nitrous Oxide Decomposition Catalyst," published December 8, 1994, which is incorporated herein by reference. Particularly preferred zeolites are beta zeolites and dealumination zeolites Y.

Carbon, preferably activated carbon, can be prepared from carbon adsorption compositions consisting of activated carbon and binders such as polymers known in the art. The carbon adsorption composition can be applied to the atmospheric contact surface. Activated carbon can adsorb hydrocarbons, volatile organic components, bacteria, pollen and the like. Another adsorption composition may comprise a component capable of adsorbing SO ₃ . A particularly useful SO ₃ adsorbent is calcium oxide. Calcium oxide is converted to calcium sulfate. The calcium oxide adsorbent composition may also contain a vanadium or platinum catalyst that can be used to convert sulfur dioxide into sulfur trioxide, which can then be adsorbed onto calcium oxide to form calcium sulfate.

In addition to the process of treating atmospheric air containing pollutants at ambient or ambient operating conditions, the present invention relates to hydrocarbons, nitrogen, using conventional three-way catalysts supported on electrically heated catalysts as known in the art. Consideration is given to the catalytic oxidation and / or reduction of oxides and residual carbon monoxide. The electrically heated catalyst may be located on the electrically heated catalyst monolith 56 described in FIG. 1. Such electrically heated catalyst substrates are known in the art and are described in US Pat. Nos. 5,308,591 and 5,317,869, which may be incorporated herein by reference. For the purposes of the present invention, the electrically heated catalyst is a metal honeycomb having a suitable thickness suitable for the flow direction, preferably 1/8 inch to 12 inches, more preferably 0.5 inch to 3 inches. When the electrically heated catalyst has to fit in a narrow space, it can be 0.25 to 1.5 inches thick. The preferred support is a plurality of fine parallels extending from the inlet side to the outlet side of the carrier such that the passage is open such that air flow enters from the front 26 and passes through the monolith 56 in the direction to the fan 20. It is a monolithic carrier of the type having a gas flow passage. Preferably the passage is essentially straight from its inlet to its outlet and is defined by a wall coated with a washcoat such that the gas flow through the passage is in contact with the catalytic material. The flow path of the monolithic carrier is a thin wall channel that can be of any suitable cross-sectional shape and size formed from a metal component that is trapezoidal, rectangular, square, ovoid, hexagonal, ovoid, annular, or corrugated flat form known in the art. . Such structures may include at least about 60 to 600 gas inlet holes (“cells”) per cross-sectional area of 1 in ² . This monolith can be made of any suitable material and can preferably be heated upon application of a current. Suitable catalysts for application are ternary catalysts (TWCs) which can enhance the oxidation of hydrocarbons and carbon monoxide as well as the reduction of nitrogen oxides as recited above. Useful TWC catalysts are described in US Pat. No. 4,714,694; 4,738,947; 5,010,051; 5,010,051; 5,057,483 and 5,139,992.

The invention is illustrated in more detail by the following examples, which are not intended to limit the scope of the invention.

<Example 1>

The 1993 Nissan Altima Radiator Core (Nissan Part No. 21460-1E400) was heat treated with 450 ° C. in air for 16 hours to clean and oxidize the surface, then poured an aqueous slurry containing silica-alumina through the radiator channel and Blowing with an air gun, drying with a pan at room temperature, and calcining at 450 ° were coated in part with a high surface area silica-alumina undercoat (dry load = 0.23 g / in ³ ). Silica-alumina slurry is prepared by ball milling a high surface area calcined SRS-II alumina (Davison) with acetic acid (0.5% based on alumina) and water (about 20% total solids) so that 90% of the particle size is <4 μm. It was. The ball milled material was then blended with the nalco silica sol (# 91SJ06S-28% solids) at a rate of 25% / 75%. SRS-II alumina has a structure of xSiO ₂ · yAl ₂ O ₃ · zH ₂ O and after activation is specified to be 92-95 wt% Al ₂ O ₃ and 4-7 wt% SiO ₂ . The BET surface area is stated to be at least 260 m ² / g after calcination.

Pd / Mn / Al ₂ O ₃ catalyst slurry (nominal 10 wt% palladium on alumina) was prepared by impregnating high surface area SRS-II alumina (Davison) to an initial wetting point with an aqueous solution containing sufficient palladium tetraamine acetate. The powder obtained here was dried and then calcined at 450 ?? for 1 hour. This powder was subsequently mixed with an aqueous solution of manganese nitrate (equivalent to 5.5 wt.% MnO _{2 on} alumina powder) and sufficient dilution water under high shear to give a slurry of solids 32-34%. The radiator was coated with this slurry, dried in air using a fan and then calcined in air at 450 ° for 16 hours. This ozone depletion catalyst contained palladium (dry load = 263 g / radiator volume ft ³ ) and manganese dioxide (dry load = 142 g / ft ³ ) on high surface area SRS-II alumina. A partially coated radiator reassembled with a refrigerant tank, also referred to as a header, is shown in FIG. 8.

The ozone depletion performance of the coated catalyst was estimated by blowing an air stream containing a given concentration of ozone through the radiator channel at a typical face velocity of travel speed and then measuring the concentration of ozone exiting the back of the radiator. The air temperature was about 20 ° and the dew point was about 35 °. The refrigerant liquid was circulated through the radiator at about 50 degrees Celsius. Ozone concentrations ranged from 0.1-0.4 ppm. Ozone conversion was measured to be 43% at linear air velocity (surface velocity) equivalent to 12.5 miles per hour (mph), 33% at 25 mph, 30% at 37.5 mph and 24% at 49 mph.

Example 2 (comparative)

Portions that were not coated with the catalyst of the same radiator used in Example 1 were similarly evaluated for ozone depletion performance (ie, control experiments). No conversion of ozone was observed.

<Example 3>

After 60 hours of air treatment at 450 ° C., the Lincoln Town car radiator core (part # F1VY-8005-A) was subjected to various different ozone depleting catalyst compositions (ie different catalysts, catalyst loads, binder compositions and heat treatments). Coated sequentially into 6 "x 6" square pieces. Some of the radiator pieces were pre-coated with high surface area alumina or silica-alumina and calcined at 450 ° before coating with catalyst. The actual coating was performed similarly to Example 1 by pouring an aqueous slurry containing a specific catalyst composition through a radiator channel, blowing off the excess with an air gun and drying with a pan at room temperature. The radiator cores were then dried at 120 'or dried at 120' and then calcined at 400 to 450 '. The radiator core is then reattached to the plastic tank and the ozone depletion performance of the various catalysts To 50 ?? And a face velocity of 10 mph as measured in Example 1.

Table I below summarizes the various catalysts coated on the radiator. Details of catalyst slurry preparation are given below.

Pt / Al ₂ O ₃ catalyst (2 wt% Pt nominally Al ₂ O ₃ phase) was charged with 520 g of 114 g of platinum salt solution (17.9% Pt) derived from H ₂ Pt (OH) ₆ dissolved in amine. Dissolved in was prepared by impregnating 1000 g of Condea SBA-150 high surface area (specified at about 150 m ² / g) alumina powder. Subsequently 49.5 g of acetic acid were added. The powder was then dried at 110 ° for 1 hour and calcined at 550 ° for 2 hours. The catalyst slurry was then prepared by adding 875 g of powder to 1069 g of water and 44.6 g of acetic acid in a ball mill and grinding the mixture to a particle size of 90% <10 μm. (Pieces 1 and 4)

Carbon catalyst slurries are available from Grant Industries, Inc., Elmwood Park, NJ. It was a formulation (solid content 29%) purchased from (Grant Industries, Inc.). This carbon is derived from coconut husks. These include acrylic binders and antifoams (pieces 8 and 12)

The Carulite ^R 200 catalyst (CuO / MnO ₂ ) was first ball milled with 1000 g of Carulite ^R 200 (purchased from Carus Chemical Company, Chicago, Illinois) with 1500 g of water to achieve a particle size of 90% <6 μm. Prepared by Carrullite ^R 200 is specified to contain 60 to 75 wt% MnO ₂ , 11 to 14 wt% CuO and 15 to 16 wt% Al ₂ O ₃ . The resulting slurry was diluted to about 28% solids and then mixed with either 3% (based on solids) Nalco # 1056 silica sol or 2% (based on solids) National Starch # x4260 acrylic copolymer. (Pieces 5, 9 and 10)

Pd / Mn / Al ₂ O ₃ catalyst slurry (10 wt.% Pd on nominal alumina) was prepared as described in Example 1. (Pieces 2, 3, and 6)

IW (Initial Wet) Pd / Mn / Al ₂ O ₃ catalyst (nominal 8% Pd and 5.5% MnO ₂ based on alumina) was first wetted with an aqueous solution containing palladium tetraamine acetate with high surface area SRS-II alumina (Davison). Similar preparation was made by impregnation to the point. After drying and subsequent calcination of the powder at 450 ° C. for 2 hours, the powder was re-impregnated to an initial wetting point with an aqueous solution containing manganese nitrate. Again, after drying and calcining at 450 ° for 2 hours, the powder was mixed in a ball mill with sufficient water to produce a slurry of acetic acid (3% by weight of catalyst powder) and 35% solids. This mixture was then ground until the particle size became 90% <8 μm. (Pieces 7 and 11)

SiO ₂ / Al ₂ O ₃ precoat slurry was prepared as described in Example 1. (Pieces 3 and 11)

Al ₂ O ₃ pre-coating slurry is prepared by ball milling high surface area Condea SBA-150 alumina with acetic acid (5% by weight based on alumina) and water (about 44% total solids) so that the particle size is 90% <10 μm. It was. (Pieces 9 and 12)

The results are summarized in Table I. For Segment # 4, the carbon monoxide conversion rate after the vehicle ran 5,000 miles was measured under the conditions listed in Example 1. Radiator temperature 50 ?? And no conversion was observed at 10 mph linear speed.

Catalyst Summary piece # catalyst Ozone Conversion Rate (%) One Pt / Al ₂ O ₃ , 0.67 g / in ³ (23 g / ft ³ Pt), no precoat, no calcining (120 ?? only) 12 2 Pd / Mn / Al ₂ O ₃ , 0.97 g / in ³ (171 g / ft ³ Pd), no precoat, calcined 450 ?? 25 3 Pd / Mn / Al ₂ O ₃ , 1.19 g / in ³ (209 g / ft ³ Pd), SiO ₂ / Al ₂ O ₃ precoat (0.16 g / in ³ ), calcined 450 ?? 24 4 Pt / Al ₂ O ₃ , 0.79 g / in ³ (27 g / ft ³ Pt), no precoat, calcined 450 ?? 8 5 Carulite 200, 0.49 g / in³, 3% SiO₂/ Al₂O₃Binder, no precoat, calcined 400 ?? 50 6 Pd / Mn / Al ₂ O ₃ , 0.39 g / in ³ (70 g / ft ³ Pd), no precoat, calcined 450 ?? 28 7 IW Pd / Mn / Al ₂ O ₃ , 0.69 g / in ³ (95 g / ft ³ Pd), no precoat, no calcining (120 ?? only) 50 8 Carbon, 0.80 g / in ³ , no precoat, no calcining (120 ?? only) 22

piece # catalyst Ozone Conversion Rate (%) 9 Carulite 200, 0.65 g / in ³ , 3% SiO ₂ / Al ₂ O ₃ binder, Al ₂ O ₃ precoat (0.25 g / in ³ ), calcined 450 ?? 38 10 Carulite 200, 0.70 g / in ³ , 2% latex binder, no precoat, no calcining (120 ?? only) 42 11 IW Pd / Mn / Al ₂ O ₃ , 0.59 g / in ³ (82 g / ft ³ Pd), SiO ₂ / Al ₂ O ₃ precoat (0.59 g / in ³ ), neither calcined nor coated (120 ?? just) 46 12 Carbon, 1.07 g / in ³ , Al ₂ O ₃ precoat (0.52 g / in ³ ), calcined to 450 ??, top not calcined (120 ?? only) 17

<Example 4>

The 1993 Nissan Altima Radiator Core (Nissan Part No. 21460-1E400) was heat treated for 16 hours at 400 ° in air, then an aqueous slurry containing alumina was poured through the radiator channel and the excess was blown into the air gun and then panned at room temperature. Was coated with Condea high surface area SBA-150 alumina (dry load = 0.86 g / in ³ ) by drying to 400 ??. Alumina precoated slurries were prepared as described in Example 3. The radiator was then sequentially coated into 2 "x 2" pieces using seven different CO destruction catalysts (Table II). Each coating was applied by pouring an aqueous slurry containing a specific catalyst composition through a radiator channel, blowing off the excess with an air gun and drying with a pan at room temperature.

Carrullite ^R and 2% Pt / Al ₂ O ₃ catalysts (pieces # 4 and # 6, respectively) were prepared following the procedure described in Example 3. 3% Pt / ZrO ₂ / SiO ₂ catalyst (piece # 3) first calcined 510 g of zirconia / silica frit (95% ZrO ₂ /5% SiO ₂ -Magnesium Elektron XZO678 / 01) at 500 ?? for 1 hour Made by. The catalyst slurry then further added 79.2 g of platinum salt solution (18.2% Pt) derived from 480 g of deionized water, 468 g of the obtained powder, 42 g of glacial acetic acid, and H ₂ Pt (OH) ₆ solubilized with an amine. It was prepared by. The mixture obtained here was ground in a ball mill for 8 hours to give a particle size of 90% <3 μm.

3% Pt / TiO ₂ catalyst (piece # 7) was prepared in 500 g of TiO ₂ (Degussa P25), 500 g of deionized water, 12 g of concentrated ammonium hydroxide, and H ₂ Pt (OH) in a conventional blender. 82 g of platinum salt solution (18.2% Pt) derived from ₆ ). Five minutes of blending resulted in a particle size of 90% <5 μm, then sufficient deionized water was added to reduce 32.7 g of nalco 1056 silica sol and solids content to about 22%. The mixture obtained here was blended in a roll mill to mix all the components.

3% Pt / Mn / ZrO ₂ catalyst slurry (piece # 5) is a manganese / zirconia frit consisting of a coprecipitation of 20% by weight manganese and 80% by weight zirconium based on the weight of metal in a ball mill (Magnesium Elektron XZO719 / 01) 70 g, 100 g deionized water, 3.5 g acetic acid, and 11.7 g platinum salt solution (18.2% Pt) derived from H ₂ Pt (OH) ₆ solubilized with amine. The mixture obtained here was ground for 16 hours to give a particle size of 90% <10 μm.

The 2% Pt / CeO ₂ catalyst (piece # 1) contains 54.9 g of H ₂ Pt (OH) ₆ derived from H ₂ Pt (OH) ₆ solubilized with amine and dissolved in deionized water with high surface area ceria stabilized with 490 g of alumina. Prepared by impregnation with platinum salt solution (18.2% Pt) (total volume 155 ml). The powder was dried for 6 hours at 110 ° and calcined at 400 ° for 2 hours. A catalyst slurry was then prepared by adding 491 g of powder to 593 g of deionized water in a ball mill and grinding the mixture for 2 hours to reach a particle size of 90 <4 μm. A 4.6% Pd / CeO ₂ catalyst (piece # 2) was similarly prepared through initial wet impregnation using 209.5 g (180 ml) of palladium tetraamine acetate solution.

After applying all seven catalysts, the radiator was calcined at 400 ° for about 16 hours. After attaching the radiator core to the plastic tank, an air stream containing CO (approximately 16 ppm) is blown through the radiator channel at 5 mph linear face velocity (315,000 / h space velocity) and then the concentration of CO exiting the back of the radiator The CO destruction performance of various catalysts was calculated by measuring. The temperature of the radiator was about 95 ° and the dew point of the air stream was about 35 °. The results are summarized in Table II below.

Ozone destruction performance was measured as described in Example 1 at 25 °, 0.25 ppm ozone, linear face velocity 10 mph, flow rate 135.2 L / min and hourly space velocity 640,000 / h. The dew point of the air used was about 35 °. The results are summarized in Table II below. 9 shows the CO conversion vs. temperature relationship for fragment numbers 3, 6 and 7. FIG.

Depletion of propylene by blowing an air stream containing propylene (about 10 ppm) through a radiator channel at 5 mph linear face velocity, flow rate 68.2 L / min, and space hourly rate 320,000, then measuring the concentration of propylene exiting the back of the radiator The catalyst was also tested for. The temperature of the radiator was about 95 ° and the dew point of the air stream was about 35 °. The results are summarized in Table II below.

CO / HC / Ozone Conversion Rate Summary piece # catalyst Carbon Monoxide Conversion Rate (%) ¹ Ozone Conversion Rate (%) ² Propylene Conversion Rate (%) ³ One 2% Pt / CeO ₂ 0.7 g / in ³ (24 g / ft ³ Pt) 2 14 0 2 4.6% Pd / CeO ₂ 0.5 g / in ³ (40 g / ft ³ Pd) 21 55 0 3 3% Pt / ZrO ₂ / SiO ₂ 0.5 g / in ³ (26 g / ft ³ Pt) 67 14 2 4 Carulite 200 0.5 g / in ³ , 3% SiO ₂ / Al ₂ O ₃ binder 5 56 0 5 3% Pt / Mn / ZrO ₂ 0.7 g / in ³ (36 g / ft ³ Pt) 7 41 0 6 2% Pt / Al ₂ O ₃ 0.5 g / in ³ (17 g / ft ³ Pt) 72 8 17 7 3% Pt / TiO ₂ 0.7 g / in ³ (36 g / ft ³ Pt), 3% SiO ₂ / Al ₂ O ₃ binder 68 15 18 ¹ Test conditions: 16 ppm CO, 95 ??, 5 mph face velocity, 68.2 L / min, LHSV (space velocity per hour) = 320,000 / h, air dew point = 35 ?? ² Test conditions: 0.25 ppm O ₃ , 25 ??, 10 mph face velocity, 135.2 L / min, LHSV (space velocity per hour) = 640,000 / h, air dew point = 35 ?? ³ Test conditions: 10 ppm propylene, 95 ??, 5 mph face velocity, 68.2 L / min, LHSV (space velocity per hour) = 320,000 / h, air dew point = 35 ??

Example 5

This example summarizes the technical results of on-vehicle vehicle testing conducted in February and March 1995 in the Los Angeles area. The purpose of this experiment is to measure the catalytic ozone resolution in catalyzed radiators under actual operating conditions. Los Angeles area (LA) was chosen as the most appropriate test area because of its measurable ozone levels during this March experiment period. In addition, the specific driving route is limited to the Los Angeles area, and the time is limited to the typical morning and afternoon service congestion time and non-congestion time. Two different catalyst compositions were evaluated: 1) Carulite ^R 200 (CuO / MnO ₂ / Al ₂ O ₃ , (purchased from Carus Chemical Company); and 2) Pd / Mn / Al prepared as described in Example 3 ₂ O ₃ (77 g / ft ³ Pd). Both compositions were coated in pieces on an aluminum radiator of a recent model Cadillac V-6 engine. In the radiator, the copper-copper OEM radiator on the Chevrolet Caprice test vehicle was replaced with aluminum. The outside of the car was fitted with a 1/4 "Teflon ^R PTFE sample line located directly behind each catalyst piece and behind the uncoated part of the radiator (control piece). The ambient (around catalyst) ozone level was measured in front of the radiator. The ozone concentration was measured using two Dashby Model 1003 AH ozone monitors located on the rear seat of the vehicle A temperature probe was placed on each radiator test piece directly into several inches of sample line. A single air speed probe was installed in front of the radiator in the center between the two pieces Collect data from the ozone analyzer, temperature probe, air speed probe, and vehicle speedometer to a personal computer located in the trunk and download it to a floppy disk It was.

The overall results from this experiment are summarized in Table III below. For each catalyst (Carolite ^R & Pd / Mn / Al ₂ O ₃ ), the results were recorded at low idling, hot idling and running. In February and March 1995, data were collected on two separate operations from LA. The first run was shortened after a few days due to low ambient ozone levels. While somewhat elevated during the second run in March, ambient levels averaged approximately 40 ppb. During the last three days of the experiment (March 17-20), ozone levels were highest. The peak level was approximately 100 ppb. In general, no trend in the conversion to ozone concentration was noted.

Except for the results of cold idle, the results reported in Table III are the average of the results of operating at least 11 times (the range of actual values is given in parentheses). Only data for inlet ozone concentrations above 30 ppb were included. Highway data are not included because ambient levels fall below 20 ppb. Only two runs were performed for the low idle test. Cold idling is considered to be the collection of data during idling immediately after the vehicle has started before the thermostat is activated and before pumping warm cooling fluid to the radiator. The overall ozone conversion was the highest value obtained during high temperature idling and was very good for all catalysts. This may be due to the lower face velocity associated with high temperatures and idling. Cold idle produces lower conversions due to the low ambient temperature of the radiator surface. The operating result is the median of the high and low idle results. The radiator warms up, but the temperature is lower and the face velocity is higher than what is encountered in hot idling conditions. In general, the ozone conversion measured for carrullite ^R is greater than that measured for Pd / Mn / Al ₂ O ₃ (eg 78.1: 63.0% during operation). However, during high idling and running, the average temperature of the Carulite ^R catalyst is usually 40 ° C than that of the Pd / Mn / Al ₂ O ₃ catalyst. Higher, the average radiator face speed is typically 1 mph lower.

In general, these results indicate that ozone can be decomposed at high conversion rates under normal operating conditions.

Ozone Conversion Rate Results on Road Ozone Conversion Rate (%) Temperature (??) Face velocity (mph) Vehicle speed (mph) Pd / Mn / Al ₂ O ₃ Low temperature idle 48.2 (47.2-49.2) 70.6 (70.5-70.8) 9.0 (8.9-9.2) 0.0 High temperature idling 80.6 (70.7-89.9) 120.0 (104.7-145.2) 7.4 (6.1-8.4) 0.0 driving 63.0 (55.5-69.9) 104.3 (99.2-109.6) 13.2 (12.2-14.9) 23.3 (20.5-29.7) Carulite (CuO / MnO ₂ ) Low temperature idle 67.4 (67.4-67.5) 71.8 (70.8-72.9) 8.2 (7.5-8.9) 0.0 High temperature idling 84.5 (71.4-93.5) 157.1 (134.8-171.2) 7.5 (6.7-8.2) 0.0 driving 78.1 (72.3-83.8) 143.7 (132.9-149.6) 12.2 (11.2-13.5) 19.2 (13.7-24.8) * Average value. The range is shown in parentheses.

In general, the results of the motor experiment correspond to the new activity measured in the laboratory prior to mounting the radiator. At room temperature (-20 °), 20% relative humidity (0.7% absolute water vapor), and 10 mph face velocity, the laboratory conversions for Pd / Mn / Al ₂ O ₃ and Carulite ^R were 55 and 69%. Increasing RH to 70% (2.3% absolute water vapor) at room temperature (˜20 ??) reduced the conversion to 38 and 52%, respectively. Since the cold idling (70 °) conversions measured at 9 mph face velocity are 48 and 67%, respectively, the humidity levels encountered during the experiment appear low.

The plane velocity of air entering the radiator is low. At an average running speed of about 20 mph (normal local driving), the radiator face speed is only about 13 mph. Even over 60 mph on the highway, the radiator face speed was only about 25 mph. The fan significantly regulates the air flow through the radiator. At idle, the fan is usually pulled up to about 8 mph.

<Example 6>

8 g by weight of lead on a Carulite ^R catalyst was prepared by impregnating 100 g of Carulite ^R 200 powder (crushed in a mixer) with 69.0 g of an aqueous solution containing palladium tetraamine acetate (12.6% Pd) at initial wetting. This powder was dried overnight at 90 ° C. and calcined at 450-550 ° C. for 2 hours. 92 g of the resulting calcined catalyst was combined with 171 g of deionized water using a ball mill to produce a 35% solids slurry. Particle size 90% ?? After 30 minutes of milling at 9 μm, 3.1 g of National Starch x4260 acrylic latex binder (50% solids) was added and the resulting mixture was further milled for 30 minutes to disperse the binder. Compositions containing 2, 4, and 6 wt.% Pd on the Carulite ^R catalyst were similarly prepared and evaluated.

The catalyst was evaluated for ozone decomposition at room temperature and 630,000 / hour face rate using a wash-coated 300 cpsi (square inch per cell) ceramic honeycomb. Catalyst samples were prepared as mentioned above. The results are summarized in Table IV. As shown, the 4 and 8% Pd / Kallite ^R catalysts calcined at 450 ° C. generated initial and 45 minute ozone conversions (about 60 and 62%, respectively). These results corresponded to the case of carrullite ^R alone under the same experimental conditions. 2 and 4% Pd catalyst calcined at 550 ° produced a significantly lower conversion (47%) after 45 minutes. This is due to the loss of surface area at high temperatures in the calcination process. When the 6% catalyst was also calcined at 550 ° C., there was no significant drop in activity.

Ozone results (300 cpsi honeycomb, 630,000 / hr face velocity) catalyst Load (g / in ³ ) % Conversion, initial % Conversion, 45 minutes Pd on Carulite 200 4% Pd / Calulite (calcined at 450 ??) 1.8 64 59 8% Pd / Kalulite (calcined at 450 ??) 2.0 61 60 2% Pd / Calulite (calcined at 550 ??) 2.1 57 48 4% Pd / Calulite (calcined at 550 ??) 1.9 57 46 6% Pd / Calulite (calcined at 550 ??) 2.3 59 53

<Example 7>

A series of experiments were conducted to evaluate several catalyst compositions comprising a palladium component for treating air containing 0.25 ppm ozone. This air is at ambient conditions (23 ??, 0.6% moisture). The composition was coated on 300 cells per inch with a ceramic (coredite) flow through honeycomb at a load of about 2 g washcoat per cubic inch of substrate. A coated monolith containing several supported palladium catalysts was dropped into a 1 "diameter stainless steel pipe and the air stream was passed vertically over the opening of the honeycomb at a space velocity of 630,000 / hour. And at the outlet The one alumina support used was SRS-II gamma alumina (purchased from Davidson) characterized by that described in Example 1 (surface area about 300 m ² / g). A small surface area theta alumina was used, characterized by a surface area of ² / g and an average aperture radius of about 80 ° E. The E-160 alumina has a surface area of about 180 m ² / g and an average aperture radius of about 47 ° Gamma alumina has a surface area of about 120 m ² / g and an average aperture radius of 28 ° C. Also, the ratio of silica to alumina is about 250: 1 and the surface area is about 430 m ² /. g Dealumina beta zeolite was used Carbon, in particular microporous wood carbon, characterized by having a surface area of about 850 m ² / g was used as a support Finally, purchased from Long-Plan, approximately 110 m ² / Titania (grade DT51), characterized by the surface area of g, was used as the support The results are shown in Table V, including the relative weight percents of the various catalyst components, the dropping for honeycomb, the initial ozone conversion, and the conversion after 45 minutes. Summarized.

Ozone results (300 cpsi honeycomb, 630,000 / hour space velocity, 0.6% moisture; about 0.25 ppm ozone) catalyst Load (g / in ³ ) % Conversion, initial % Conversion, 45 minutes IW 8% Pd / 5% Mn / Al ₂ O ₃ 1.8 64 55 IW 8% Pd / 5% Mn / Al ₂ O _{3 at} low surface area 1.9 64 60 8% Pd / Al ₂ O _{3 with} low surface area 1.9 56 44 8% Pd / E-160 Al ₂ O ₃ 2.2 61 57 4.6% Pd / CeO ₂ 1.99 59 58 8% Pd / beta Zeolite (Dealuminated) 1.9 38 32 5% Pd / C 0.5 63 61 8% Pd / DT-51 TiO ₂ 1.8 39 20

<Example 8>

The following is a process for preparing a Carulite ^R slurry comprising a vinyl acetate latex binder and used to coat the radiator to induce good adhesion of the catalyst to the aluminum radiator.

1000 g of Carulite ^R 200, 1500 g of deionized water, and 50 g of acetic acid (5% based on Carulite ^R ) were combined in a gallon ball mill and ground for 4 hours to 90% particle size. It was 7 micrometers. After draining the resulting slurry from the mill, 104 g (based on 5% solids) of National Starch Dur-O-Set E-646 crosslinked EVA copolymer (48% solids) were added. After fully blending the binder, the slurry was rolled on the mill for several hours without milling medium. This slurry was coated with a piece of aluminum substrate (e.g. radiator) and dried for 30 minutes at 30 ° C to obtain good adhesion (e.g. no peeling off of the coating). Hot curing (up to 150 degrees) can be used if desired.

Example 9

As described in Example 6, carbon monoxide conversion was tested by coating several titania compositions supported on platinum on a ceramic honeycomb. The catalyst load was about 2 g / in ³ and the experiment was carried out using an air stream with 16 ppm of carbon monoxide (dew point 35 °) at a space velocity of 315,000 / hour. The catalyst composition was reduced on honeycomb at 300 ° C. for 3 hours using a forming gas having 7% H ₂ and 93% N ₂ . Compositions containing TiO ₂ comprise 2 and 3 weight percent platinum component on P25 titania; And 2 and 3 weight percent platinum components on DT52 grade titania. Titania of the DT51 grade was purchased from Long-Plant and has a surface area of approximately 110 m ² / g. DT52 grade titania was tungsten containing Tania purchased from Long-Plant and having a surface area of approximately 210 m ² / g. P25 grade titania was purchased from Degussa and was characterized by having a particle size of approximately 1 μm and a surface area of about 45-50 m ² / g. This result is shown in FIG.

<Example 10>

Example 10 relates to the evaluation of CO conversion of compositions containing alumina, ceria and zeolites. The support is characterized in that described in Example 7. The compositions evaluated were 2 weight percent platinum on low surface area theta alumina; Platinum and ceria 2% by weight; 2 weight percent platinum on SRS-II gamma alumina and 2 weight percent platinum on beta zeolite. The results are shown in FIG.

<Example 11>

CO conversion over temperature was measured for compositions containing 2% by weight of platinum on SRS-II gamma alumina phase and ZSM-5 zeolite coated on a 1993 Nissan Altima radiator as described in Example 4, and Example 4 Experiments were performed using the same procedure for testing CO as used for. The results are shown in FIG.

<Example 12>

0.659 g of a solution of platinum hydroxide in which amine containing 17.75 wt% platinum was dissolved was slowly added to a 20 g 11.7 wt% aqueous slurry of titania sol in a glass beaker and stirred with a magnetic stirrer. A 400 cell metal monolithic core sample 1 inch long by 1 inch diameter per square inch (cpsi) was immersed in the slurry. The channels were cleaned by blowing air into the coated monolith and the monolith was dried at 110 ° C. for 3 hours. This time, the monolith was immersed in the slurry, the air was blown into the channel and the step of drying at 110 degrees was repeated. Two coated monoliths were calcined at 300 ° C. for 2 hours. The uncoated metal monolith was weighed out to 12.36 g. After the first immersion, the weight was 14.06 g, the total weight gain was 0.69 g with 12.6 g after the first drying, 14.38 g after the second immersion and 13.05 g after calcination. The coated monolith has 72 g / ft ³ of platinum based on the metal and is represented by 72 Pt / Ti. The catalyst was evaluated in an air stream containing 20 ppm of carbon monoxide at a gas flow rate of 36.6 liters per minute. After this initial evaluation, the catalyst core was reduced at 300 ° C. for 12 hours in a forming gas having 7% hydrogen and 93% nitrogen, and the evaluation for the treatment of the air stream containing 20 ppm of carbon monoxide was repeated. The reduced coated monolith could be designed to be 72 Pt / Ti / R. Precoated 5: 1 weight ratio of platinum to rhodium at 40 g per square inch and ES-160 (alumina) at 2.0 g per cubic inch, with 11 cells ㅧ 10 cells ㅧ 0.75 inch long monolith and 33 pt / 7Rh / Al The aforementioned slurry was evaluated using a core sample obtained from a ceramic monolith having 400 cells per square inch by immersing a core designed into the above mentioned slurry and cleaning the channel by blowing air. This monolith was dried at 110 ° C. for 3 hours and calcined at 300 ° C. for 2 hours. The catalyst substrate comprising the first platinum and rhodium layer was 2.19 g. After the first immersion, weighed was 3.40 g and 2.38 g after calcination, with a total weight gain of 0.19 g at 0.90 g per cubic inch of platinum / titania slurry. The immersed ceramic core contains 74 g of platinum per cubic foot based on platinum metal and is designed to be 74 Pt / Ti // Pt / Rh. The results are shown in FIG.

Example 13

The platinum catalyst on titanium mentioned in Example 12 above was used in an air stream containing 4 ppm propane and 4 ppm propylene. It was a space velocity of standard hourly space velocity of 650,000 in the air stream. Platinum and titanium catalysts have 72 g of platinum per cubic foot of the substrate and the total catalyst used. This was evaluated on a ceramic honeycomb as mentioned in Example 13. For propylene conversion the measured results were 16.7% at 65 °; 19% at 70 ??; 23.8% at 75 ??; 28.6% at 80 °; 35.7% at 85 ° C .; 40.5% at 95 °; And 47.6% at 105 °.

<Example 14>

Example 14 is a description of the platinum component on the titania support. This example illustrates the excellent activity of platinum supported on titania in the case of oxidation of carbon monoxide and hydrocarbons. Evaluation was made using a catalyst prepared from a colloidal titania sol to form a composition comprising 5.0 weight percent platinum component based on the weight of platinum metal and titania. Platinum was added to titania in the form of an amine dissolved platinum hydroxide solution. It was added to the colloidal titania slurry or to the titania powder to produce a platinum and titania containing slurry. This slurry was coated onto a ceramic monolith with 400 cells per square inch (cpsi). Samples have varying coating amounts of 0.8-1.0 g / in. The coated monolith was calcined and reduced to 300 ° C. in air for 2 hours. This reduction reaction was carried out at 300 ° C. for 12 hours in a gas containing 7% hydrogen and 93% nitrogen. The colloidal titania slurry contained 10 weight percent titania in an aqueous medium. Titania has a particle size of nominally 2-5 nm.

Carbon monoxide conversion was measured in an air stream containing 20 ppm of CO. In various experiments the flow rate of carbon monoxide ranges from a space velocity of 300,000 to 650,000 VHSV at ambient temperatures up to 110 ° C. The air used is air purified from the air cylinder and moisture is added to the air as it passes through the water bath. When irradiating moisture, the relative humidity varied from 0 to 100% at room temperature (25 °). The carbon monoxide containing air stream passed through the ceramic monolith coated with the catalyst composition using a space velocity of 650,000 / hour.

FIG. 13 is reduced at 300 ° C. for 12 hours using air with 20 ppm CO to measure carbon monoxide conversion over temperature and using a reducing gas containing 7% hydrogen and 93% nitrogen as described above. A study is shown comparing the platinum (Pt / Ti-R) supported on titania to the non-reduced platinum catalyst (Pt / Ti) coating solution supported on titania. 13 illustrates the significant advantages of using a reduced catalyst.

FIG. 14 illustrates a comparison of platinum on reduced titania with various supports including platinum on tin oxide (Pt / Sn), platinum on zinc oxide (Pt / Zn) and platinum on ceria (Pt / Ce). do. All samples were reduced under the conditions indicated above. The flow rate of carbon monoxide in the air was 650,000 VHSV. As shown, reduced platinum on colloidal titania has significantly higher conversion results than platinum on several other support materials.

Hydrocarbon oxidation was measured using 6 ppm propylene air mixture. The propylene air stream passed through the catalyst monolith at a space velocity of 300,000 VHSV at various temperatures from room temperature to 110 degrees Celsius. Propylene concentration was measured using a flame ionized detector before and after the catalyst. This result is summarized in FIG. 15. The support used was 5% by weight based on the weight of platinum metal and yttrium oxide Y ₂ O ₃ . The reduced and non-reduced catalysts were compared. As shown in Figure 15, reducing the catalyst significantly improves propylene conversion.

The platinum catalyst supported on the titania mentioned above was reduced in a forming gas containing 7% hydrogen and 93% nitrogen at 500 ° C. for 1 hour. The conversion of carbon monoxide was evaluated in 0% relative humidity air at a flow rate of 50,000 VHSV. Evaluation was performed to determine if the reduction of the catalyst was reversible. The catalyst was initially evaluated for its ability to convert carbon monoxide at 22 °. As shown in FIG. 16, the catalyst converted about 53% of carbon monoxide and dropped to 30% after approximately 200 minutes. At 200 minutes, heating the air and carbon monoxide to 50 ° C. increased the carbon monoxide conversion to 65%. The catalyst was further heated to 100 ° C. in air and carbon monoxide, held at 100 ° C. for 1 hour, and then cooled in air to room temperature (about 25 ° C.). Initially the conversion rate dropped to about 30% in about 225-400 minutes. This evaluation was continued from 100 ° to 1200 minutes with a conversion rate of about 40%. A study of the same purpose was performed at 50 degrees. At about 225 minutes the conversion was about 65%. After 1200 minutes, the conversion increased substantially to about 75%. This example shows that the reduction of the catalyst permanently improves the catalytic activity.

<Example 15>

Example 15 is used to account for ozone conversion at room temperature for platinum and / or palladium components supported on manganese oxide / zirconia coprecipitates. This example also shows a platinum catalyst which catalyzes the conversion of ozone to oxygen and simultaneously oxidizes carbon monoxide and hydrocarbons. Manganese oxide / zirconia mixed oxide powders having 1: 1 and 1: 4 weights were prepared based on the Mn and Zr metals. Coprecipitates were prepared according to the process described in US Pat. No. 5,283,041, referenced above. 3% and 6% Pt (based on 1: 4 weight of Mn versus Zr) on the manganese / zirconia catalyst was prepared as described in Example 4. SBA-150 gamma alumina (10% based on the weight of the mixed oxide powder) was added as a binder in the form of a 40% water slurry containing acetic acid (5% by weight alumina powder) and ground to a particle size of 90% <10 μm. I was. 6 wt% Pd catalyst was prepared by impregnating manganese / zirconia frit (based on 1: 1 weight of Mn to Zr) with an aqueous solution containing palladium tetraamine acetate to the initial wet point. The powder was dried at 450 ° C. for 2 hours and then calcined, and then the catalyst was mixed in a ball mill with nalco # 1056 silica sol (10 wt% catalyst powder) and sufficient water to prepare a slurry of about 35% solids. The mixture was then triturated until the particle size became 90% <10 μm. Various samples were reduced using a forming gas having 7% H ₂ and 93% N ₂ at 300 ° C. for 3 hours. Evaluations were performed to determine the conversion of ozone on coated radiator minicores from a 1993 Altima radiator, approximately f inches x ⅞ inches x 1 inch deep. The evaluation was performed at room temperature using a stainless steel pipe 1 inch in diameter as described in Example 7 with house air (lab feed air) with 0.25 ppm inlet ozone concentration and 630,000 / hour space velocity. The results are provided in Table VI.

Summary of Fresh Active Ozone Results (39 cpsi Nissan Altima Core, 630,000 / Time Space Velocity; 25 ° C; 0.25 ppm Ozone; Residential Air-Approximately 0.6% Water) Core number catalyst Load (g / in ³ ) Initial conversion rate (%) % Conversion after 45 minutes One 3% Pt / MnO ₂ / ZrO ₂ (1: 4) (calcined at 450 °) 0.7 70.7 65.8 2 3% Pt / MnO ₂ / ZrO ₂ (1: 4) (calcined at 450 °; reduced at 300 °) 0.7 70.5 63.7 3 6% Pt / MnO ₂ / ZrO ₂ (1: 4) (calcined at 450 °) 0.68 68.2 62.3 4 6% Pt / MnO ₂ / ZrO ₂ (1: 4) (calcined at 450 °; reduced at 300 °) 0.66 66 55.8 5 6% Pt / MnO ₂ / ZrO ₂ (1: 1) 10% by weight of nalco 1056 0.39 38.3 21.1 6 MnO ₂ / ZrO ₂ (1: 1) 10% by weight of nalco 1056 0.41 58.3 44.9 7 MnO ₂ / ZrO ₂ (1: 1) 10% by weight of nalco 1056 0.37 55.8 41.2 8 3% Pt / ZrO ₂ / SiO ₂ (calcined at 450 °) 0.79 27.4 10 9 3% Pt / ZrO ₂ / SiO ₂ (calcined at 450 ° and reduced at 300 °) 0.76 54.2 30.1

As can be seen from Table VI Cores 1 and 2 with only 3% platinum, the initial and 45 minutes of ozone conversion for both the reduced and unreduced catalysts were good. Cores 3 and 4 at 6% platinum concentration also showed good results, but not as good as the results of 3% platinum. Cores 5 to 7 describe various other support materials used to cause the conversion of ozone. Core 5 had palladium on manganese oxide / zirconia coprecipitates, which was below expectations but still resulted in significant ozone conversion. Cores 6 and 7 used co-precipitants without precious metals and also showed significant ozone conversion, but are not as good as with platinum as catalyst. Core 8 was platinum on calcined but not reduced zirconia / silica support and core 9 was platinum on reduced zirconia / silica support. Cores 8 and 9 both provided some conversion, but were not better than the conversion obtained by platinum on the coprecipitate.

In addition, carbon monoxide conversion was assessed on a 39 cpsi radiator minicore, as cited for 3% and 6% platinum on manganese / zirconia supports. Reduced and non-reduced samples were evaluated. For purposes of explanation, there are also platinum on zirconia / silica supports and platinum on reduced and unreduced carrullite ^R. As can be seen from FIG. 17, the results of 3% reduced platinum on the manganese / zirconia support were higher than in the case compared to the other embodiments.

<Example 16 (comparative)>

Ozone conversion is measured by blowing an ozone (0.25 ppm) containing air stream through the radiator channel at 10 mph linear velocity (630,000 / hour space velocity) at room temperature and 80 ° C. and then measuring the concentration of ozone leaving the back of the radiator. Measurements were taken on a 1995 Ford Contour radiator. The air stream had a dew point of about 35 degrees. The heated refrigerant did not circulate through the radiator, but the air stream was heated with a heating tape to achieve the desired radiator temperature if necessary. Further testing was conducted on a Ford Taurus radiator "mini" of uncoated 0.75 inch (length) x 0.5 inch (width) x 1.0 inch (diameter) in a 1 inch diameter stainless steel pipe as described in Example 7. -Core ". The air stream was heated with a heating tape to achieve the desired radiator temperature. 120 in both of the tests ?? Ozone decomposition was not observed below.

<Example 17>

Ozone conversion was measured at various temperatures for the 3% Pt / TiO ₂ catalyst reduced in the absence and in the presence of 15 ppm CO. Degussa P25 grade titania was used as a support, characterized by a particle size of about 1 μm and a surface area of about 45-50 m 2 / g. The catalyst was coated onto 300 cpsi ceramic (cordierite) honeycomb and reduced on honeycomb using a forming gas having 7% H ₂ and 93% N ₂ at 300 ° C. for 3 hours. The test was performed as previously described in Example 7. The air stream (dew point of 35 ° F.) was heated with a heating tape to achieve the desired temperature. As can be seen in FIG. 18, a conversion improvement of about 5% of pure ozone was observed at 25 to 80 degrees. The presence of CO improves the conversion of ozone.

Example 18

Impregnated with 100 g of Versal GL alumina purchased from LaRoche Industries Inc., approximately 28 g of Pt amine hydroxide (Pt (A) salt) diluted in water to a solution of about 80 g I was. 5 g of acetic acid was added to fix Pt to the alumina surface. After mixing for 30 minutes, the Pt impregnated catalyst was slurried by adding water to bring the solids to about 40%. This slurry was ball milled for 2 hours. Particle size was determined to be 90% less than 10 μm. The catalyst was coated onto a 400 cpsi ceramic substrate 1.5 "in diameter and 1.0" in length to give a washcoat load of about 0.65 g / in ³ after drying. The catalyst was then dried at 100 ?? and calcined at 550 ?? for 2 hours. This catalyst was charged with 60 ° C. in dry air as described in Example 21. It was tested for C ₃ H ₆ oxidation at temperatures of from 100 ° to 100 °.

Some of the calcined Pt / Al ₂ O ₃ samples described above were reduced for 1 hour at 400 ° in 7% H ₂ / N ₂ . The reduction step was carried out by increasing the catalyst temperature from 25 ° to 400 ° at a H ₂ / N ₂ gas flow rate of 500 cc / min. Incremental temperature was about 5 ?? / min. The catalyst was cooled to room temperature and then tested for C ₃ H ₆ oxidation as described in Example 21.

Example 19

After 6.8 g of ammonium tungstate was dissolved in 30 cc of water and the pH was adjusted to 10, the solution was impregnated onto 50 g of Versal GL alumina (LaRoche Industries Inc.). The material was dried at 100 ?? and calcined at 550 ?? for 2 hours. Approximately 10 metal wt% of W on Al ₂ O ₃ was cooled to room temperature and impregnated with 13.7 g of Pt amine hydroxide (18.3% Pt). 2.5 g of acetic acid was added and mixed well. Water was then added to make the catalyst a slurry containing 35% solids. The slurry was then coated onto a ceramic substrate of 400 cpsi, 1.5 "x 1.0" diameter to obtain a catalyst washcoat load of 0.79 g / in ³ after drying. The coated catalyst was then dried and calcined at 550 ° C. for 2 hours. 60 calcined catalyst ?? Tests were made in C ₃ H ₆ and dry air in the temperature range of from 100 ° C.

Example 20

6.8 g of perenic acid (36% Re in solution) was further diluted in water to make a 10 g% perenic acid solution. The solution was impregnated onto 25 g of Versal GL alumina. The impregnated alumina was dried and the powder calcined at 550 ° for 2 hours. A weight percent of Re powder based on 10 metal by weight of the impregnated Al ₂ O ₃ phase was then further impregnated with 6.85 g of Pt amine hydroxide solution (18.3% Pt metal in solution). 5 g of acetic acid were added and mixed for 30 minutes. Slurry was made by adding water so that the solid content was 28%. The slurry was ball milled for 2 hours and coated onto a 1.5 "wide by 1.0" long 400 cpsi ceramic substrate to obtain a catalyst washcoat load of 0.51 g / in ³ after drying. The catalyst coated substrate was dried at 100 ° C. and then calcined at 550 ° C. for 2 hours. Catalyst 60 ?? The test was conducted in calcined form using 60 ppm C ₃ H ₆ and dry air in the temperature range of from 100 to 100 °.

Example 21

The catalysts of Examples 18, 19 and 20 were tested in a microreactor. The catalyst sample was 0.5 "in diameter and 0.4" in length. The supply is 25 ?? It consisted of 60 ppm C ₃ H ₆ in dry air in the temperature range from 100 ° to 100 °. C ₃ H ₆ was measured at 60, 70, 80, 90 and 100 ?? in steady state conditions. The results are summarized in Table VII below.

Summary Results for C ₃ H ₆ Conversion Rate Catalyst name Pt / Al ₂ O ₃ Calcination (Example 18) Pt / Al ₂ O ₃ Calcination and Reduction (Example 18) Pt / 10% W / Al ₂ O ₃ Calcined (Example 19) Pt / 10% Re / Al ₂ O ₃ Calcined (Example 20) C ₃ H ₆ conversion (%) 60 ?? 0 10 9 11 70 ?? 7 22 17 27 80 ?? 20 50 39 45 90 ?? 38 70 65 64 100 ?? 60 83 82 83

From the table above it is clear that the addition of W or Re oxide enhanced the activity of Pt / Al ₂ O ₃ in the calcined form. The C ₃ H ₆ conversion of calcined Pt / Al ₂ O ₃ was markedly improved when the catalyst was reduced at 400 ° C. for 1 hour. Improved activity was observed in the calcined catalyst also by the introduction of W or Re oxide.

<Example 22>

This is an example of the preparation of high surface area cryptomelan using MnSO ₄ .

Molar ratio: KMnO ₄ : MnSO ₄ : Acetic acid = 1: 1.43: 5.72

Concentration of Mn in the solution before mixing:

0.44 M KMnO ₄

0.50 M MnSO ₄

Chemical Formula KMnO ₄ = 158.04 g / mol

Formula MnSO ₄ H ₂ O = 169.01 g / mol

Formula weight C ₂ H ₄ O ₂ = 60.0 g / mol

The following steps were performed.

1. Make a solution of 3.50 moles (553 g) of KMnO ₄ in 8.05 L of deionized water and heat to 68 °.

2. Use 1260 g of glacial acetic acid and dilute to 10.5 L with deionized water to make 10.5 L of 2 N acetic acid. The density of this solution is 1.01 g / ml.

3. Weigh 5.00 mol (846 g) of manganese sulfate hydrate (MnSO ₄ H ₂ O), dissolve in 10,115 g of the 2N acetic acid solution and heat to 40 ??.

4. Add the solution obtained in 3. over 15 minutes with continuous stirring to the solution obtained in 1. After the addition is complete, the slurry begins to heat at the next heating rate.

1:06 pm 69.4 ??

1:07 pm 71.2 ??

1:11 pm 74.5 ??

1:15 pm 77.3 ??

1:18 pm 80.2 ??

1:23 pm 83.9 ??

1:25 pm 86.7 ??

1:28 pm 88.9 ??

5. Collect approximately 100 ml of slurry from the vessel at 1:28 pm and immediately filter into Buchner funnel, wash with 2 L deionized water and dry in 100 ?? The sample was determined to have a BET multipoint surface area of 259.5 m ² / g.

<Example 23>

This is an example of preparation of high surface area cryptomelan using Mn (CH ₃ COO) ₂ .

Molar ratio: KMnO ₄ : Mn (CH ₃ CO ₂ ) ₂ : Acetic acid = 1: 1.43: 5.72

Chemical Formula KMnO ₄ = 158.04 g / mol, Aldrich Lot # 08824MG

Formula weight of _{Mn (CH 3 CO 2) 2} · H 2 O = 245.09 g / mol, Aldrich lot # 08722HG

Formula weight C ₂ H ₄ O ₂ = 60.0 g / mol

The following steps were performed:

1. Make a solution of 2.0 mol (316 g) of KMnO ₄ in 4.6 L of deionized water and heat to 60 ° on a hot plate.

2. Prepare 6.0 L of 2N acetic acid by using 720 g glacial acetic acid and diluting to 6.0 L with deionized water. The density of this solution is 1.01 g / ml.

3. Weigh 2.86 moles (700 g) of manganese (II) acetate tetrahydrate [Mn (CH ₃ CO ₂ ) ₂ .4H ₂ O] and dissolve in 5780 g of the 2N acetic acid solution (in a reactor vessel). Heated to 60 ° in the reactor vessel.

4. Add the solution obtained in 1. to the solution obtained in 3 while maintaining the slurry at 62-63 ?? After the addition is complete, gently heat the slurry as follows.

82.0 at 3:58 pm ??

86.5 at 4:02 pm ??

87.0 at 4:06 pm ??

87.1 at 4:08 pm ??

Heat off

The slurry is then quenched by pumping 10 L of deionized water into the vessel. The slurry is then cooled to 58 ?? at 4:13 pm.

The slurry was filtered on a Buchner funnel. The filter cake obtained was placed in 12 L of deionized water, slurried again and stirred overnight in a 5 gallon vessel using a mechanical stirrer. The washed product was refiltered in the morning and then dried in 100 ?? in an oven. The sample was determined to have a BET multipoint surface area of 296 m ² / g. The obtained cryptomelan is understood by the XRD pattern of FIG. This is expected to have an IR spectrum similar to that shown in FIG.

<Example 24>

The following is an explanation of the ozone test method for measuring the ozone decomposition percentage used in this example. A test apparatus consisting of an ozone generator, a gas flow regulator, a blister generator, a cold mirror dew point hygrometer, and an ozone detector was used to determine the percentage of ozone destroyed by the catalyst sample. Ozone was generated in situ in a flowing gas stream consisting of air and water vapor using an ozone generator. Ozone concentration was measured using an ozone detector and moisture content was measured using a dew point hygrometer. The sample has a dew point of 15 ?? And inlet ozone concentrations of 4.5 to 7 ppm in a gas stream flowing at approximately 1.5 L / min. Samples were tested with particles of -25 / + 45 mesh size held between glass wool plugs placed in inner diameter 1/4 "ID Pyrex ^R glass tubes. The tested samples filled 1 cm portions of glass tubes.

Sample tests usually required 2 to 16 hours for the conversion to reach steady state. Samples typically showed a near 100% conversion when the test began and then slowly declined to a "leveling" conversion that remained static for a longer period of time (48 hours). After steady state, conversion was calculated by the following equation: Ozone conversion (%) = [1- (Ozone concentration after passage of catalyst) / (Ozone concentration before passage of catalyst)] X 100.

In the ozone depletion test for the sample of Example 22, 58% conversion was obtained.

In the ozone depletion test for the sample of Example 23, an 85% conversion was obtained.

<Example 25>

This example is intended to demonstrate that the method of Example 23 produced a "clean" high surface area Cryptomellan in which ozone depletion performance was no longer enhanced by calcination and washing. A 20 g portion of the sample shown in Example 23 was calcined in air at 200 ° C. for 1 hour, cooled to room temperature and washed by stirring the slurry in 200 ml of deionized water at 100 ° C. for 30 minutes. The product obtained was filtered and dried at 100 ?? in an oven. The target was determined to have a BET multipoint surface area of 265 m ² / g. In the ozone destruction test of the sample, a conversion of 85% was obtained. Compared to the sample test of Example 23, it is demonstrated that no benefit in ozone conversion from washing and calcining the sample of Example 23 is recognized at all.

Example 26

Samples of high surface area cryptotomelan were obtained from commercial suppliers and changed by calcination and / or washing. The powders obtained and changed were tested for ozone depletion performance according to the method of Example 24 and characterized by powder X-ray diffraction, infrared spectroscopy and BET surface area measurement by nitrogen adsorption.

<Example 26a>

Samples of commercially available high surface Cryptomellan (Chemetals, Inc., Baltimore, MD) were washed with 60 ° deionized water for 30 minutes, filtered, rinsed and oven dried at 100 °. The ozone conversion of the sample in the water was 64% compared to 79% of the washed material. The wash did not change the surface area or crystal structure (223 m ² / g Cryptomellan) of this material, as measured by nitrogen adsorption and powder X-ray diffraction, respectively. Infrared spectroscopy, however, removed the peaks at 1220 and 1320 wavenumbers in the spectra of the washed samples, indicating removal of sulfate group anions.

<Example 26b>

Samples of commercially available high surface area Cryptomellan (Chemetals, Inc., Baltimore, MD) were calcined for 4 hours at 300 ° and 8 hours at 400 °. The ozone conversion of the material in question was 44% compared to 71% of the sample calcined at 300 ° and 75% of the sample calcined at 400 °. Calcination is 300 ?? Or 400 ?? There was no substantial change in the surface area or crystal structure (334 m ² / g Cryptomellan) of the sample. 400 ?? Trace amounts of Mn ₂ O ₃ were detected in the sample. Calcination causes dehydroxylation of these samples. Infrared spectroscopy showed that the intensity of the band between 2700 and 3700 wavenumbers assigned to the surface hydroxyl groups was reduced.

Example 27

The addition of Pd black (containing Pd metals and oxides) to high surface area cryptomelan has been found to significantly improve ozone decomposition performance. Pd black powder and (1) commercially available Cryptomellan (300 'calcined sample described in Example 26b) and (2) powder of high surface area Cryptomellan synthesized in Example 23, calcined for 1 hour at 200' Samples were prepared that were physically mixed. These samples were prepared by mixing powders of Pd black and Cryptomellan in a weight ratio of 1: 4 in the dry state. The dry mixture was shaken until the color was uniform. To the mixture in the beaker was added deionized water to a solids content of 20-30% to form a suspension. Aggregates in the suspension were mechanically broken using a stir bar. The suspension was sonicated for 10 minutes in a Bransonic model 5210 ultrasonic cleaner and then oven dried at 120 ° -140 ° for approximately 8 hours.

The ozone conversion of commercial cryptomellan calcined at 300 ° C. was 71% as measured in the powder reactor (Example 26b). Mixing this product sample with 20% by weight of Pd black yielded a conversion of 88%.

Cryptomellan samples prepared as in Example 23, calcined at 200 ° C. had a conversion of 85%. Performance improved to 97% with 20% by weight of Pd black added.

<Example 28>

1500 g of high surface area manganese dioxide (Cryptomellan, purchased from Chemetals) and 2250 g of deionized water in a 1-gallon ball mill for 90 hours Grinded to 7 μm. The resulting slurry was drained from the mill into a separate one gallon vessel, then sufficient KOH (20% solution in deionized water) was added to raise the pH to about 9.5. Then additional KOH was added for several days to maintain the pH at 9.5. Then 294 g (10% solids) of National Starch x-4280 acrylic latex polymer (51% solids) were added. The binder was thoroughly blended by rolling the vessel containing the slurry on two roll mills. The vessel did not contain a milling medium such as a ceramic milling ball. The slurry prepared according to the present method was coated onto various kinds of substrates and had excellent adhesion. The substrate included a porous monolithic support (eg, ceramic honeycomb) with a coating applied thereon by immersing the honeycomb in a slurry. The slurry was also spray coated onto an aluminum radiator. The slurry was also dip coated on a small radiator minicore of the kind described above. In addition, multifiber filter media of the type used in the filter air were coated by dipping or spraying. Typically, the samples were coated under load conditions that could vary from 0.15 to 1.5 g per cubic inch. Samples were typically air dried for at least 2 hours, until dry at 30 ° C. In each case the catalyst adhesion was good (ie the coating did not peel off). Higher drying temperatures (up to 150 ° C) can be used if necessary. The latex hardens during drying.

<Example 29>

To 96.56 g of the ball milled catalyst slurry obtained in Example 1 (prior to KOH addition) 3.20 g (based on 3% solids) of the Long-Plan Colloid 226 polymer dispersant were added. After rolling the mixture on a roll mill for several hours, 7.31 g (10% solids) of National Starch x-4280 acrylic latex polymer (51% solids) was added. As in Example 28, the binder was thoroughly blended by rolling the slurry containing vessel onto two roll mills. The vessel did not contain a milling medium, such as a ceramic milling ball. The slurry prepared according to the method was coated onto various kinds of substrates, which showed good adhesion. The substrate contained a porous monolithic support (eg, ceramic honeycomb) with the honeycomb immersed in the slurry and a coating applied thereon. The slurry was also dip coated onto a small radiator minicore of the kind recited above. Typically, samples were coated under load that could vary from 0.15 to 1.5 g per cubic inch. Samples were air dried at 30 ° C. for at least 2 hours until dry. In each case good catalyst adhesion was achieved (ie the coating did not peel off). Higher temperatures of drying (up to 150 ° C) can be used if necessary. The latex hardens during drying.

<Example 30>

8.9 g deionized water was added to 1.1 g TiO ₂ nanopowder in beer. The pH was adjusted to 9.5 by addition of ammonia / water concentrate. A solution of platinum hydroxide in which an amine with 17.75 wt% platinum was dissolved was mixed slowly to obtain 5 wt% platinum on titania. Subsequently, a 20% by weight containing palladium nitrate solution based on the palladium metal was added with mixing to obtain 14.3% palladium on titania. 400 cell (cpsi) metal monolithic core samples of 1 inch diameter x 1 inch length per square inch were immersed in the slurry. Air was blown onto the coated monolith to clean the channels and the monolith was dried at 110 ° C. for 3 hours. This time, the monolith was once again immersed in the slurry and the steps of blowing the air into the channel and drying at 110 ° C were repeated. Two coated monoliths were calcined at 300 ° C. for 2 hours. After this initial evaluation the catalyst core was reduced for 12 hours at 300 ° C. in a forming gas with 7% hydrogen and 93% nitrogen. The catalyst was evaluated in an air stream containing 20 ppm of carbon monoxide and 20 ppm of C ₁ based hydrocarbons. Hydrocarbons were evaluated in the presence of 20 ppm CO. Hydrocarbons evaluated at 36.6 liters per minute gas flow rate corresponding to 300,000 standard hourly space velocity (SHSV) were ethylene C ₂ =, propylene C ₃ =, and pentene C ₅ =. The air stream had a relative humidity (RH) of 30%. The results are depicted in FIG. 21.

Related Applications

This application is a partial application of US Patent Application No. 08 / 589,182, filed January 19, 1996, and 08 / 589,182 is a partial application of US Patent Application No. 08 / 537,206, filed September 29, 1995. , 08 / 537,206, is a partial continuing application of US Patent Application No. 08 / 410,445, filed March 24, 1995, and 08 / 410,445 is No. 08 / 376,332, filed January 20, 1995. As partly filed, all of which are incorporated herein by reference.

Claims (24)

Particulate catalytically active materials comprising a manganese compound and having a BET N ₂ surface area of greater than 150 m ² / g; Dispersants comprising at least one compound selected from the group consisting of polymers containing carboxylic acid groups, esters of polymers containing carboxylic acid groups and salts of polymers containing carboxylic acid groups; Polymeric binders, including latex emulsion particles; And water A catalyst slurry for attaching the substrate. The catalyst slurry of claim 1, wherein the particulate catalytically active material has a BET N ₂ surface area of greater than 200 m ² / g. The catalyst slurry of claim 1, wherein about 90% of the particulate catalytically active material particles are less than 8 microns. The catalyst slurry of claim 1, wherein the particulate catalytically active material further comprises a platinum group metal. The catalyst slurry of claim 1, wherein the manganese compound is MnO ₂ . The catalyst slurry of claim 1 wherein the polymeric binder comprises one or more compounds selected from the group consisting of acrylic polymers and poly (vinyl) acetates. The catalyst slurry of claim 1, wherein the dispersant is a polymer acrylate. Forming a mixture comprising water and particulate catalytically active material, wherein the catalytically active material comprises a manganese compound and has a BET N ₂ surface area of greater than 150 m ² / g; Adding to the mixture a dispersant comprising at least one compound selected from the group consisting of polymers containing carboxylic acid groups, esters of polymers containing carboxylic acid groups and salts of polymers containing carboxylic acid groups; Adding a polymer binder comprising latex emulsion particles to the mixture Slurry forming method comprising a. The method of claim 8, wherein the particulate catalytically active material has a BET N ₂ surface area of greater than 200 m ² / g. The method of claim 8, wherein about 90% of the particulate catalytically active material particles are less than 8 microns. The method of claim 8, wherein the particulate catalytically active material further comprises a platinum group metal. The method of claim 8, wherein the manganese compound is MnO ₂ . The method of claim 8, wherein the polymeric binder comprises one or more compounds selected from the group consisting of acrylic polymers and poly (vinyl) acetates. The method of claim 8, wherein the dispersant is a polymer acrylate. The method of claim 8, further comprising adjusting the pH of the mixture to at least 8.5. Applying the catalyst slurry to the atmospheric contact surface of the vehicle, wherein the catalyst slurry is Particulate catalytically active materials comprising a manganese compound and having a BET N ₂ surface area of greater than 150 m ² / g; Dispersants comprising at least one compound selected from the group consisting of polymers containing carboxylic acid groups, esters of polymers containing carboxylic acid groups and salts of polymers containing carboxylic acid groups; Polymeric binders, including latex emulsion particles; And water That will include, air purification method. The method of claim 16, wherein the particulate catalytically active material has a BET N ₂ surface area of greater than 200 m ² / g. The method of claim 16, wherein about 90% of the particulate catalytically active material particles are less than 8 microns. The method of claim 16, wherein the particulate catalytically active material further comprises a platinum group metal. The method of claim 16, wherein the manganese compound is MnO ₂ . The method of claim 16, wherein the polymeric binder comprises at least one compound selected from the group consisting of acrylic polymers and poly (vinyl) acetates. The method of claim 16 wherein the dispersant is a polymer acrylate. The method of claim 16, wherein the vehicle is a motor vehicle. The method of claim 23, wherein the atmospheric contact surface is a radiator.