CN105080566A - Flue gas denitrification powder catalyst as well as preparation method and application thereof - Google Patents

Abstract

The invention relates to a flue gas denitrification powder catalyst, a preparation method and an application thereof. The catalyst includes titanium dioxide and manganese oxide as main components and additives, and the additives are any three or more combinations of zirconium, copper, molybdenum, cerium, iron, nickel, cobalt, niobium or tungsten oxides, Wherein the molar ratio of Mn/Ti is (0.01-1.0), and the molar ratios of each metal in the auxiliary agent to the titanium metal element are all independently (0.01-1.0). The catalyst of the present invention is prepared by co-precipitation method. The catalyst can be used in the selective catalytic reduction (NH ₃ -SCR) purification process of nitrogen oxides in flue gas from stationary sources and mobile sources. The catalyst adopts non-toxic and harmless raw materials, and has the advantages of simple preparation method, high catalytic activity, high _N2 selectivity, wide activity window, resistance to low _- concentration SO2 poisoning and water vapor poisoning, and environmental friendliness.

Description

A kind of flue gas denitrification powder catalyst, preparation method and application thereof

technical field

The invention belongs to the technical field of catalyst preparation, and in particular relates to a flue gas denitrification powder catalyst, a preparation method and an application thereof.

Background technique

With the development of my country's economy, energy consumption, especially petrochemical energy consumption, has increased significantly. Correspondingly, the degree of air pollution is also increasing day by day, and the energy structure dominated by coal is the main factor affecting the quality of my country's air environment.

At present, more than 95% of thermal power plants in my country are mainly coal-fired, and it is difficult to change in the short term. Sulfur dioxide, carbon dioxide, nitrogen oxides and dust emitted during coal combustion account for 87%, 71%, 67% and 60% of my country's emissions, respectively. China's energy consumption accounts for 8% to 9% of the world's total, but its _NOx emissions reach about 10%. Among them, the _NOx released by coal combustion accounts for 67% of the country's total NOx emissions.

Nitrogen oxides, including NO, NO ₂ , N ₂ O, N ₂ O ₃ , etc., are one of the main sources of air pollutants, which can cause harm to the human respiratory system, and are also important causes of photochemical smog and acid rain. Foreign experience shows that selective catalytic reduction technology (SCR) using NH ₃ as reducing agent is currently the most effective method for flue gas denitrification.

There are two main technologies for eliminating _NOx in stationary source flue gas, one is reduction method and the other is oxidation method. Reduction methods include selective catalytic reduction and non-selective catalytic reduction. Selective catalytic reduction (SCR) is less affected by boiler operating conditions, easy to control, high denitrification efficiency (up to 90%), low ammonia escape rate, requires catalyst, high investment and operating costs, mature technology application . Selective non-catalytic reduction (SNCR) uses liquid ammonia, urea and other reducing agents to spray into the furnace to selectively react with _NOx . It has the advantages of simple equipment and low investment and operation costs, but the denitrification efficiency is only 30-50%. And ammonia escape rate is high, the application is greatly restricted. The oxidation method (LOTOxTM technology) utilizes a strong oxidant (O ₃ ) to oxidize the poorly soluble NO into water-soluble N ₂ O ₃ and N ₂ O ₅ high-valence nitrogen oxides, which are absorbed and dissolved by the washing tower. The preparation cost of O ₃ is relatively high, and the ozone generator has low efficiency, large power consumption, and large land occupation, and the cost limits the application of this technology. The SCR process is currently the most widely used and most mature technology. The core of NH ₃ -SCR technology is the SCR catalyst system. Different SCR catalysts have different optimal temperature ranges for reducing NO _x .

At present, V ₂ O ₅ /TiO ₂ catalysts are widely used commercially. The stability of the catalyst is improved by adding additives such as WO ₃ , MO ₃ , and CeO ₂ . The reaction temperature is maintained above 350°C to avoid the impact of SO ₂ on The poisoning effect of the catalyst, for this reason the denitrification device must be placed before the air preheater of the boiler system and the electrostatic precipitator to meet the requirements for the reaction temperature. In this way, the high concentration of soot in the flue gas will affect the denitrification efficiency, stability and life of the catalyst. If the denitrification device containing high-temperature SCR catalyst is placed after desulfurization, the erosion and poisoning effect of dust on the catalyst will be greatly reduced, the environment will be relatively clean, and equipment modification will be simpler. Therefore, the development of a low-temperature catalyst that can place the denitrification device behind the electrostatic precipitator can not only avoid the influence of dust, but also use the waste heat of the flue gas itself to carry out the SCR reaction, so the research and development of low-temperature, high activity, anti-SO ₂ and H ₂ O poisoning The SCR catalyst is currently a research hotspot in flue gas denitrification abroad.

In recent years, environmentally friendly NH ₃ -SCR catalysts have received extensive attention. The catalyst disclosed in CN1724149A uses titanium dioxide as a carrier, and two or more variable metals or oxides as catalyst promoters, and the reduction efficiency of the catalyst is kept above 82%. The catalyst disclosed in CN103182312A uses the impregnation method to use _TiO2 as a carrier to support Mn, Ce and Nb oxides, and the denitrification conversion rate of flue gas with high water vapor content in the range of 80-200 °C can reach more than 50%. Yao Yao et al. (Yao Yao et al., Low-temperature selective catalytic reduction and denitrification performance of titanium nanotube-supported manganese catalysts, Journal of Fuel Chemistry, 2011 (9)) prepared MnO _x /TiNT catalysts by impregnation method, and the conversion rate of NO reached 95%. %above. Deng Shanshan et al. (Deng Shanshan et al., MnO _x -SnO ₂ /TiO ₂ catalyst low temperature NH ₃ Selective Catalytic Reduction of NO Chemical Industry Progress, 2013) prepared MnO _x -SnO ₂ /TiO ₂ at 130-250 It has a good NO conversion rate in the temperature range of ℃. ^CN103055848A discloses a low-temperature denitrification catalyst doped with rare earths and its preparation method. Its main active elements are Mn, Fe, Ce, and TiO ₂ is used as a carrier. The denitrification activity can reach 80-98%. Xu et al. (WenqingXu, YunboYu, Changbin Zhang, HongHe, Selective catalytic reduction of NO by NH ₃ overaCe/TiO ₂ catalyst. Catalysis Communications 9(2008) 1453-1457) prepared by impregnation method Ce/TiO ₂ catalyst can achieve more than 95% NO conversion in the range of 250-375 ℃ NO conversion rate (GHSV=25000h ^-1 ), tested at 300°C for 12h under a flue gas atmosphere containing 3% H ₂ O + 100ppmSO ₂ , the NO conversion rate was stable at 90% (GHSV=50000h ^-1 ). Shan et al. (WenpoShan, FudongLiu, HongHe, XiaoyanShi, Changbin Zhang, Anenvironmentally-benignCeO ₂ -TiO ₂ catalyst for the selective catalytic reduction of NOx with NH ₃ stimulated dieselexhaust. CatalysisToday184(2012) 160-165) compared OeO ₂ prepared by co-precipitation method with 2Ce/ _{OTiO 2} (mentioned above) low-temperature activity is significantly increased, especially when the reaction temperature is 200 ° C, the NOx conversion rate increased by more than 40%, CeO ₂ -TiO ₂ ability to withstand high space velocity and high temperature thermal stability are also significantly improved. Shan et al. (WenpoShan, FudongLiu, HongHe, XiaoyanShi, Changbin Zhang, AsuperiorCe-W-TimixedoxidecatalystfortheselectivecatalyticreductionofNOxwithNH ₃ .AppliedCatalysisB:Environmental115–116(2012)100–106) prepared _CeWTiOx catalysts with a wide range of transition metal W by doping, 100% _NOx conversion rate and N ₂ generation selectivity (GHSV=250000h ^-1 ) are realized within the operating temperature window (250-400°C). After testing for 12 hours under the flue gas atmosphere of 5% H ₂ O+100 ppm SO ₂ , the NO _x conversion rate dropped from the initial 100% to 60% (GHSV=250000h ^-1 ). The catalyst disclosed in CN101069855A uses mesoporous molecular sieves as carriers, and heteropoly compounds as active components. The denitrification efficiency of the catalyst prepared by this method can reach 92% at 150°C. The catalyst disclosed in CN101028594A includes a carrier and a catalytic active component, the active component is a manganese-cobalt-cerium composite oxide, and the active oxide is impregnated on the carrier by an impregnation method. CN103071506A discloses an iron-cerium-titanium composite oxide catalyst, using excess urea precipitant, in the absence of SO2 and water, when the space velocity is 50000h ^-1 _, the denitrification efficiency can reach more than 85% at 300-400 ° C, select The denitrification rate is 100%, and when the water content is 5% or the SO ₂ content is 100ppm, the denitrification rate can maintain 90% within 24 hours at 300°C. CN102764643A discloses a vanadium-titanium oxide catalyst resistant to poisoning by alkali metals and alkaline earth metals. The catalyst is doped with element Ce in the vanadium-titanium oxide catalyst. The catalyst has excellent anti-alkali metal poisoning performance, especially the doped cerium component improves the anti-alkali metal poisoning performance of the V ₂ O ₅ /(MoO ₃ ) _x (WO ₃ )1-x-TiO ₂ catalyst At the same time, it has no effect on the SCR catalyst activity. CN103252232A discloses a zirconium-doped vanadium-based oxide catalyst for the selective catalytic reduction of nitrogen oxides by ammonia and a preparation method thereof. The catalyst is a metal oxide catalyst formed by loading zirconium and vanadium oxides on the surface of titanium-tungsten powder. The invention can greatly improve the catalytic performance of traditional vanadium-based catalysts such as high-temperature stability and _N2 generation selectivity through the method of zirconium doping. CN103240079A discloses a cerium-zirconium-tungsten composite oxide catalyst for the selective catalytic reduction of nitrogen oxides by ammonia, a preparation method and an application thereof. The catalyst is a metal composite oxide composed of three metals: cerium, zirconium and tungsten. The invention adopts non-toxic and harmless raw materials, and prepares a cerium-zirconium-tungsten composite oxidation compound that can adapt to high space velocity reaction conditions, has excellent catalytic activity, high selectivity for _N2 generation, and wide operating temperature window through a simple and easy method. material catalyst. CN103816891A discloses a cerium-molybdenum-zirconium composite oxide catalyst, the molar ratio of Ce and Zr in the catalyst is 1:2; the molar ratio of Mo and Ce is 0.1-1.5. By adjusting the proportion of cerium, molybdenum and zirconium in the cerium-molybdenum-zirconium composite oxide catalyst, the invention obtains a nitrogen oxide conversion catalyst with a wide temperature window, high conversion rate, excellent thermal stability and anti-sintering ability catalyst. CN104368329A discloses a cerium-niobium-zirconium composite oxide catalyst, a preparation method and an application thereof. The catalyst has the following chemical composition: CeNb _a Zr ₂ O _x , wherein a is 0-1.0 and 0 is not included. The catalyst has excellent low-temperature activity, wide operating temperature window, high _N2 selectivity and high _NOx conversion rate, and can be used for _NH3 -SCR reaction.

Although the above-mentioned catalysts have higher reactivity, nitrogen selectivity, higher thermal stability and wide temperature window, they are not suitable for high space velocity (60,000h ^-1 ), containing sulfur dioxide (≥100ppm) and water vapor (10% H ₂ O) low-temperature flue gas, the conversion rate of NO _x is not very high, and the stability is not high.

Contents of the invention

In order to develop a new type of environmentally friendly, green, high-efficiency low-temperature SCR denitrification catalyst, to overcome the poor catalyst activity, narrow temperature window, and insufficient long-term stability of the existing denitrification catalysts in low-temperature flue gas containing sulfur dioxide (100ppm) and water vapor (10%) , the object of the present invention is to provide a low ^- temperature (100-200°C) flue gas denitrification powder catalyst, preparation method and application thereof. The conversion rate of NO _x in low-temperature flue gas of steam (10%) is high, and the preparation method of the catalyst is simple and feasible.

In order to achieve the above object, the present invention adopts the following technical solutions:

A low-temperature flue gas denitrification powder catalyst, including titanium dioxide, manganese oxide and additives as main components, the additives are copper oxide, zirconium oxide, molybdenum oxide, cerium oxide, iron oxide, nickel oxide , cobalt oxide, tungsten oxide or niobium oxide, any three or a combination of three or more.

The combination means that the auxiliary agent is a composite oxide of at least three metals synthesized by a co-precipitation method.

The auxiliary agent can also be any four or any species of copper oxide, zirconium oxide, molybdenum oxide, cerium oxide, iron oxide, nickel oxide, cobalt oxide, tungsten oxide or niobium oxide , any six, any seven, any eight or nine combinations.

Preferably, the molar ratio of Mn element to Ti element is 0.01-1.0, such as 0.01, 0.02, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, preferably, the molar ratio of Mn/Ti 0.01 to 0.5.

Preferably, the molar ratio of each metal in the additive to the titanium metal element is independently 0.01 to 1.0, such as 0.01, 0.02, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, preferably , the molar ratio of the metal to the titanium metal is 0.01-0.5. Catalysts in this molar ratio range can be used in a clean reaction atmosphere with a space velocity (60,000h ^-1 ) and in a low-temperature flue gas with a space velocity (60,000h ^-1 ) and a low concentration of sulfur dioxide (100ppm) and water vapor (10%) The conversion rates of NO _x are all very high, wherein the catalyst has a high conversion rate of NO _x at a high space velocity (60,000h ^-1 ), and it can maintain a conversion rate of more than 90% at 100-200°C. In the low-temperature flue gas with space velocity (60,000h ^-1 ), low concentration of sulfur dioxide (100ppm) and water vapor (10%), the conversion rate of more than 80% can still be maintained at 100-200°C.

An exemplary flue gas denitrification powder catalyst of the present invention is a titanium-manganese-copper-nickel-cerium composite oxide catalyst in which the molar ratio of Ti, Mn, Cu, Ni, and Ce is 1:0.4:0.2:0.02:0.1; Titanium-manganese-iron-copper-zirconium-cerium composite oxide catalyst with the molar ratio of Ti, Mn, Fe, Cu, Zr and Ce six elements being 1:0.2:0.1:0.2:0.01:0.1; Ti, Mn, Fe, Cu, Zr , The molar ratio of the six elements of Co is 1:0.3:0.01:0.1:0.1:0.1 Timanganese-copper-zirconium-cobalt composite oxide catalyst; the molar ratio of the seven elements of Ti, Mn, Fe, W, Co, Ni, Ce Titanium-manganese-iron-tungsten-cobalt-nickel-cerium composite oxide catalyst with a ratio of 1:0.12:0.15:0.05:0.1:0.05:0.2; the molar ratio of Ti, Mn, Fe, Zr, and Ce is 1:0.4:0.05: 0.05:0.2 titanium manganese iron zirconium cerium composite oxide catalyst; Ti, Mn, Cu, Nb, Ce five elements molar ratio of 1:0.5:0.2:0.01:0.1 titanium manganese copper nickel cerium composite oxide catalyst; Ti, Mn, Fe, Zr, Co, Ni and Ce with a molar ratio of 1:1.0:0.1:0.2:0.4:0.2:0.2 titanium-manganese-iron-zirconium-cobalt-nickel-cerium composite oxide catalyst; Ti, Mn, Titanium-manganese-iron-nickel-niobium-cerium composite oxide catalyst with a molar ratio of Fe, Ni, Nb and Ce six elements of 1:0.25:0.2:0.6:0.05:0.2; six kinds of Ti, Mn, Cu, Co, Ce, Mo The molar ratio of elements is 1:0.5:0.2:0.01:1.0:0.01 titanium manganese copper cobalt cerium molybdenum composite oxide catalyst. The above-mentioned catalyst has a high conversion rate of NO _x at a space velocity (60,000h ^-1 ), and it can maintain a conversion rate of more than 90% at 100-200°C in a clean atmosphere without sulfur and water. (60,000h ^-1 ), containing low concentrations of sulfur dioxide (100ppm) and water vapor (10%), the conversion rate of NO _x is very high, and it can still maintain a conversion rate of more than 80% at 100-200°C. °C for a long time reaction, within 12 hours, the conversion rate of more than 90% can still be maintained.

The second object of the present invention is to provide a method for preparing the above-mentioned low-temperature flue gas denitrification powder catalyst, which is prepared by adopting the coprecipitation method to obtain the aforementioned low-temperature flue gas denitrification powder catalyst.

The coprecipitation method comprises the following steps:

(1) Weigh any three or more combinations of soluble copper source, zirconium source, molybdenum source, cerium source, iron source, nickel source, cobalt source, tungsten source or niobium source solution into the soluble titanium source and In the manganese source solution (the amount of which can be determined by the molar ratio of each metal in the additive to titanium metal), mix evenly to obtain a metal mixed solution;

(2) Mix the metal mixed solution with the precipitant solution, control the temperature, pH value, stirring speed and time of the mixed solution, make the metal ion precipitate completely, then static aging, separate the obtained precipitate suspension to obtain a filter cake, wash , dried, and roasted to obtain a low-temperature flue gas denitrification powder catalyst.

Preferably, the titanium source is selected from any one or a mixture of at least two of titanium tetrachloride, metatitanic acid, titanyl sulfate or tetrabutyl titanate.

Preferably, the manganese source is selected from any one or a mixture of at least two of manganese nitrate, manganese acetate or manganese chloride.

Preferably, the copper source is selected from any one or a mixture of at least two of copper nitrate, copper chloride or copper sulfate.

Preferably, the zirconium source is selected from any one or a mixture of at least two of zirconium nitrate, zirconium oxychloride, zirconium acetate or zirconium sulfate.

Preferably, the molybdenum source is selected from ammonium molybdate or/and sodium molybdate.

Preferably, the cerium source is selected from any one or a mixture of at least two of cerium nitrate, cerium sulfate or cerous chloride.

Preferably, the iron source is selected from any one or a mixture of at least two of ferric nitrate, ferric chloride, ferric sulfate or ferric phosphate.

Preferably, the nickel source is selected from any one or a mixture of at least two of nickel nitrate, nickel acetate or nickel chloride.

Preferably, the cobalt source is selected from any one or a mixture of at least two of cobalt nitrate, cobalt chloride, cobalt acetate or cobalt oxalate.

Preferably, the tungsten source is selected from any one or a mixture of at least two of ammonium tungstate, potassium tungstate or sodium tungstate.

Preferably, the niobium source is selected from niobium pentachloride or/and niobium oxalate.

Preferably, the precipitating agent is any one or a mixture of at least two of sodium carbonate, ammonia water or urea.

Preferably, in step (3), the mixed metal solution is added dropwise to the precipitant solution, or the precipitant solution is added dropwise to the mixed metal solution.

Preferably, when sodium carbonate or ammonia water is used as the precipitation agent, the temperature of the mixed solution is controlled to be 0 to 40°C, such as 5°C, 10°C, 15°C, 20°C, 25°C, 30°C or 35°C, (i.e. the precipitation temperature ), when urea is used as the precipitant, the temperature of the mixed solution is controlled to be 80 to 100°C, such as 82°C, 84°C, 86°C, 88°C, 90°C, 92°C, 94°C, 96°C or 98°C (precipitation temperature ).

Preferably, the pH value of the mixed solution is controlled at 6-12, such as 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11 or 11.5, preferably 8-11. The pH value has a great influence on the properties of the precipitate, not only the hydrolysis of the metal salt, the gelation rate of the solution, the particle size, the accumulation of the primary particle and the secondary particle, and the crystal phase, but also the catalyst pore structure, strength and catalytic performance. All have effects. When using a variety of metal salt solutions to generate precipitation, in order to make the precipitation uniform, the pH value should be controlled. When multiple components co-precipitate, the solubility products of different components should be considered. In the acidic solution, the supersaturation is low, the precipitate particles are large, and the components are unevenly distributed; in the alkaline solution, the supersaturation is high, the precipitate particles are small, and the components are evenly distributed.

Preferably, the stirring time is controlled to be 1-12 hours, preferably 1-6 hours. That is, in the present invention, the precipitation is performed under stirring conditions.

Preferably, the stirring speed is controlled to be 100-4000 rpm, preferably 600-1000 rpm.

Preferably, the standing aging time is 1-24h, such as 2h, 4h, 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h or 22h, preferably 6-12h. After the precipitation is complete, let the newborn precipitate and the mother liquor be placed together for a period of time. This process is called "aging". The purpose is to remove the impurities contained in the precipitate and allow the precipitated crystal to grow and increase the crystal particle size to make the particle distribution more uniform.

Preferably, the obtained precipitated suspension is suction-filtered to obtain a filter cake.

Preferably, deionized water or distilled water is used for washing, and the washing times are 2 to 4 times, preferably 3 times. The specific washing method is, for example, adding an appropriate amount of deionized water or distilled water to the filter cake for beating, stirring and suction filtration, and repeated washing in this way to obtain a hydrogel that is substantially completely removed from impurities.

Preferably, the drying temperature is 80-120°C, preferably 100-120°C.

Preferably, the drying time is 3-24 hours, preferably 8-12 hours.

Preferably, the calcination temperature is 400-600°C, such as 420°C, 440°C, 460°C, 480°C, 500°C, 520°C, 540°C, 560°C or 580°C, preferably 500°C; if the calcination temperature is lower than 400°C will cause incomplete decomposition of metal hydroxides; if the calcination temperature is higher than 600°C, it will easily cause sintering of the catalyst, and the generated _TiO2 will undergo crystal transformation (anatase phase to rutile phase), which is not conducive to denitrification reaction. The calcination time is 4-8h, for example 4.3h, 4.6h, 4.9h, 5.2h, 5.5h, 5.8h, 6.1h, 6.4h, 6.7h, 7h, 7.3h or 7.6h, preferably 5h.

The third object of the present invention is to provide a kind of purposes of flue gas denitrification powder catalyst as above, and described catalyst is used for stationary source (such as thermal power plant and oil refinery FCC catalytic cracking regenerated flue gas denitrification) and mobile source (such as Nitrogen oxide purification of diesel vehicle exhaust).

Compared with the prior art, the present invention has the following beneficial effects:

The present invention adopts titanium dioxide and manganese oxide as the main active components of the catalyst, adopts at least three kinds of transition metal oxides as active auxiliary agents, utilizes the synergistic effect between the composite metal oxides, and optimizes the components to make the obtained catalyst It has excellent resistance to SO ₂ and water vapor poisoning, excellent long-term stability, and adapts to high space velocity. The catalyst has a high conversion rate of NO _x at a space velocity (60,000h ^-1 ), and it can maintain a conversion rate of more than 90% at 100-200°C in a clean atmosphere without sulfur and water. The conversion rate of NO _x in flue gas with low concentration of sulfur dioxide ( ^100ppm ) and water vapor (10%) is very high, and it can still maintain a conversion rate of more than 80% at 100-200°C. The reaction at 200°C for a long time can still maintain a conversion rate of more than 90% within 12 hours.

Moreover, the preparation process of the catalyst provided by the invention is simpler, and the obtained catalyst is environmentally friendly, cheap and efficient, has a large specific surface area (BET specific surface area is 100-200 m ² /g), and has excellent SCR denitrification activity.

Detailed ways

The technical solutions of the present invention will be further described below through specific embodiments.

Example 1

(1) Configure titanyl sulfate, manganese nitrate, copper nitrate, nickel nitrate, cerium nitrate solution and 10wt% sodium carbonate solution, mix titanyl sulfate, manganese nitrate, copper nitrate, nickel nitrate and cerium nitrate solution evenly to obtain a mixed solution , control the molar ratio of Ti, Mn, Cu, Ni, Ce in the mixed solution to be 1:0.4:0.2:0.02:0.1.

(2) In a constant temperature water bath at 25°C, add the above-mentioned titanium manganese copper nickel cerium salt mixture dropwise with sodium carbonate solution to completely precipitate titanium, manganese, copper, nickel, and cerium ions. 11. Stir for 3 hours at a stirring speed of 500 rpm, and leave to age for 6 hours. Suction filter the obtained precipitated suspension to obtain a filter cake, then add an appropriate amount of deionized water to the filter cake for beating, stirring, and suction filtration, and repeat the washing for 3 times in this way to obtain titanium manganese copper nickel cerium water with substantially complete removal of chloride ions gel;

(3) The hydrogel was dried in an oven at 110° C. for 5 hours, then placed in a muffle furnace, and calcined at 500° C. for 5 hours to obtain Catalyst 1 .

Example 2

(1) configure titanyl sulfate, manganese nitrate, ferric nitrate, copper nitrate, zirconium oxychloride, cerium nitrate solution and 10wt% sodium carbonate solution; and the cerium nitrate solution are uniformly mixed to obtain a mixed solution, and the molar ratio of the six elements of Ti, Mn, Fe, Cu, Zr and Ce in the mixed solution is controlled to be 1:0.2:0.1:0.2:0.01:0.1;

(2) In a constant temperature water bath at 25°C, add the above-mentioned titanium, manganese, iron, copper, zirconium and cerium salt mixture dropwise with sodium carbonate solution to completely precipitate titanium, manganese, iron, copper, zirconium, and cerium ions, and control the pH after the addition is completed. = 9-11, stir for 3 hours at a stirring speed of 500 rpm, and leave to age for 6 hours. Suction filter the obtained precipitated suspension to obtain a filter cake, then add an appropriate amount of deionized water to the filter cake for beating, stirring, and suction filtration, and repeat the washing 3 times in this way to obtain titanium manganese iron copper zirconium cerium with substantially complete removal of chloride ions Hydrogels;

(3) The hydrogel was dried in an oven at 110° C. for 5 hours, then placed in a muffle furnace, and calcined at 500° C. for 5 hours to obtain catalyst 2.

Example 3

(1) configure titanyl sulfate, manganese acetate, ferric nitrate, copper nitrate, zirconium oxychloride, cobalt nitrate solution and 10wt% sodium carbonate solution; and cobalt nitrate are uniformly mixed to obtain a mixed solution, and the molar ratio of the six elements of Ti, Mn, Fe, Cu, Zr and Co in the mixed solution is controlled to be 1:0.3:0.01:0.1:0.1:0.1;

(2) In a constant temperature water bath at 25°C, add the above-mentioned titanium, manganese, iron, copper, zirconium and cobalt salt mixture dropwise with sodium carbonate solution to completely precipitate titanium, manganese, iron, copper, zirconium, and cobalt ions. pH = 9-11, stirred for 3 hours at a stirring speed of 500 rpm, and aged for 6 hours. Suction filter the obtained precipitated suspension to obtain a filter cake, then add an appropriate amount of deionized water to the filter cake for beating, stirring, and suction filtration, and repeat the washing for 3 times in this way to obtain titanium manganese iron copper zirconium cobalt that has basically completely removed chloride ions Hydrogels;

(3) The hydrogel was dried in an oven at 110° C. for 5 hours, then placed in a muffle furnace, and calcined at 500° C. for 5 hours to obtain catalyst 3 .

Example 4

(1) Configure titanyl sulfate, manganese acetate, ferric nitrate, ammonium metatungstate solution dissolved in oxalic acid, cobalt nitrate, nickel nitrate, cerium nitrate solution and 5wt% ammonia solution; titanyl sulfate, manganese acetate, ferric nitrate, Ammonium metatungstate solution dissolved in oxalic acid, cobalt nitrate, nickel nitrate, and cerium nitrate solution are mixed evenly to obtain a mixed solution, and the molar ratio of the seven elements of Ti, Mn, Fe, W, Co, Ni, and Ce in the mixed solution is controlled as 1:0.12:0.15:0.05:0.1:0.05:0.2;

(2) In a constant temperature water bath at 0°C, add the above-mentioned titanium, manganese, iron, tungsten, cobalt, nickel and cerium salt mixture dropwise with ammonia solution to completely precipitate titanium, manganese, iron, tungsten, cobalt, nickel, and cerium ions. Control pH = 9-11, stir for 3 hours at a stirring speed of 500 rpm, and leave to age for 6 hours. Suction filter the obtained precipitated suspension to obtain a filter cake, then add an appropriate amount of deionized water to the filter cake for beating, stirring, and suction filtration, and repeat the washing for 3 times in this way to obtain titanium manganese iron tungsten cobalt nickel that has basically completely removed chloride ions Cerium hydrogel;

(3) The hydrogel was dried in an oven at 110° C. for 5 hours, then placed in a muffle furnace, and calcined at 500° C. for 5 hours to obtain catalyst 4 .

Example 5

(1) configure titanium tetrachloride, manganese nitrate, ferric nitrate, zirconium nitrate, cerium sulfate solution and 5wt% ammonia solution; mix titanium tetrachloride, manganese nitrate, ferric nitrate, zirconium nitrate, cerium sulfate solution evenly, obtain mixed Solution, control the molar ratio of Ti, Mn, Fe, Zr, Ce five elements in the mixed solution to be 1:0.4:0.05:0.05:0.2;

(2) In a constant temperature water bath at 0°C, add the titanium, manganese, iron, zirconium and cerium salt mixture dropwise into the ammonia solution to completely precipitate the titanium, manganese, iron, zirconium and cerium ions, and control the pH to 9 to 11 after the addition is completed. Stir for 3 hours at a stirring speed of 500 rpm, and leave to age for 6 hours. Suction filter the obtained precipitate suspension to obtain a filter cake, then add an appropriate amount of deionized water to the filter cake for beating, stirring, and suction filtration, and repeat the washing for 3 times in this way to obtain titanium manganese iron zirconium cerium water with substantially complete removal of chloride ions gel;

(3) The hydrogel was dried in an oven at 110° C. for 5 hours, then placed in a muffle furnace, and calcined at 500° C. for 5 hours to obtain catalyst 5 .

Example 6

(1) configure titanium oxysulfate, manganese nitrate, copper nitrate, niobium oxalate, cerium nitrate solution and 10wt% sodium carbonate solution; manganese nitrate, copper nitrate, niobium oxalate, cerium nitrate solution are mixed evenly, obtain mixed solution, control mixed solution The molar ratio of the five elements of Ti, Mn, Cu, Nb, and Ce is 1:0.5:0.2:0.01:0.1;

(2) In a constant temperature water bath at 25°C, add the above-mentioned mixture of titanium, manganese, copper, niobium, and cerium salts dropwise with sodium carbonate solution to completely precipitate titanium, manganese, copper, niobium, and cerium ions. 11. Stir for 4 hours at a stirring speed of 500 rpm, and leave to age for 12 hours. Suction filter the obtained precipitated suspension to obtain a filter cake, then add an appropriate amount of deionized water to the filter cake for beating, stirring, and suction filtration, and repeat the washing for 3 times in this way to obtain titanium manganese copper niobium cerium water with substantially complete removal of chloride ions gel;

(3) After the hydrogel was dried in an oven at 110°C for 5 hours, it was placed in a muffle furnace and calcined at 500°C for 5 hours to obtain catalyst 6.

Example 7

(1) configure titanium tetrachloride, manganese chloride, ferric nitrate, zirconium nitrate, cobalt nitrate, nickel nitrate, cerium nitrate solution; and the cerium nitrate solution are mixed evenly to obtain a mixed solution, and the molar ratio of the seven elements of Ti, Mn, Fe, Zr, Co, Ni and Ce in the mixed solution is controlled to be 1:1.0:0.1:0.2:0.4:0.2:0.2;

(2) In a constant temperature water bath at 90°C, add the above-mentioned titanium manganese iron zirconium cobalt nickel cerium salt mixture with excess urea to completely precipitate titanium, manganese, iron, zirconium, cobalt, nickel, and cerium ions. After the addition, the pH =8-10, stirred for 4 hours at a stirring speed of 600 rpm, and aged for 12 hours. Suction filter the obtained precipitated suspension to obtain a filter cake, then add an appropriate amount of deionized water to the filter cake for beating, stirring, and suction filtration, and repeat the washing for 3 times in this way to obtain titanium manganese iron zirconium cobalt nickel with substantially complete removal of chloride ions Cerium hydrogel;

(3) The hydrogel was dried in an oven at 110° C. for 5 hours, then placed in a muffle furnace, and calcined at 500° C. for 5 hours to obtain catalyst 7 .

Example 8

(1) configure titanium tetrachloride, manganese nitrate, iron nitrate, nickel nitrate, niobium pentachloride, cerium nitrate, 10wt% sodium carbonate solution; The niobium and cerium nitrate solutions are mixed evenly to obtain a mixed solution, and the molar ratio of the six elements of Ti, Mn, Fe, Ni, Nb and Ce in the mixed solution is controlled to be 1:0.25:0.2:0.6:0.05:0.2;

(2) In a constant temperature water bath at 10°C, add the above-mentioned titanium, manganese, iron, niobium and cerium salt mixture dropwise with sodium carbonate solution to completely precipitate titanium, manganese, iron, nickel, niobium, and cerium ions, and control the pH after the addition is completed. = 9-10, stir for 3 hours at a stirring speed of 500 rpm, and leave to age for 12 hours. Suction filter the obtained precipitated suspension to obtain a filter cake, then add an appropriate amount of deionized water to the filter cake for beating, stirring, and suction filtration, and repeat the washing for 3 times in this way, to obtain titanium manganese iron nickel niobium cerium with almost complete removal of chloride ions Hydrogels;

(3) After the hydrogel was dried in an oven at 110°C for 5 hours, it was placed in a muffle furnace and calcined at 500°C for 5 hours to obtain catalyst 8.

Example 9

(1) configure titanium tetrachloride, manganese nitrate, copper nitrate, cobalt nitrate, cerium nitrate solution and be dissolved in oxalic acid ammonium molybdate solution, 5wt% ammoniacal liquor; Titanium tetrachloride, manganese nitrate, copper nitrate, cobalt nitrate, The cerium nitrate solution and the ammonium molybdate solution dissolved in oxalic acid are mixed evenly to obtain a mixed solution, and the molar ratio of Ti, Mn, Cu, Co, Ce, Mo in the mixed solution is controlled to be 1:0.5:0.2:0.01:1.0 : 0.01;

(2) In a constant temperature water bath at 10°C, add the above-mentioned titanium manganese copper cobalt cerium molybdenum salt mixture dropwise with ammonia water to completely precipitate titanium, manganese, copper, cobalt, cerium, and molybdenum ions, and control pH=8 after the addition is completed ~12, stir for 2 hours, and let stand for aging for 12 hours. Suction filter the obtained precipitated suspension to obtain a filter cake, then add an appropriate amount of deionized water to the filter cake for beating, stirring, and suction filtration, and repeat the washing for 3 times in this way to obtain titanium manganese copper cobalt cerium molybdenum that has basically completely removed chloride ions Hydrogels;

(3) After the hydrogel was dried in an oven at 110°C for 5 hours, it was placed in a muffle furnace and calcined at 500°C for 5 hours to obtain catalyst 9.

Example 10

Place 0.12mL of Catalyst No. 1-9 in a tubular fixed-bed reactor, and the experimental conditions are as follows: The reaction conditions are: NO: 950ppm, NO ₂ : 50ppm, NH ₃ : 1000ppm, O ₂ : 3%, N ₂ It is the balance gas, the total gas flow rate is 120mL/min, and the reaction space velocity (GHSV) is 60,000h ^-1 . The reaction range is from 100°C to 200°C. The reaction results are shown in Table 1:

Table 1 The nitrogen oxide conversion rate of the catalyst at different temperatures in a clean flue gas atmosphere

Example 11

Place 0.12mL catalyst No. 1-9 in a tubular fixed-bed reactor, and the experimental conditions are as follows:

The reaction conditions are: NO: 950ppm, NO ₂ : 50ppm, NH ₃ : 1000ppm, O ₂ : 3%, SO ₂ : 100ppm, H ₂ O: 10vol%, N ₂ is the balance gas, the total gas flow rate is 120mL/min, The reaction space velocity (GHSV) is 60,000h ^-1 , and the reaction temperature range is 100-200°C. The reaction results are shown in Table 2:

Table 2 The conversion rate of nitrogen oxides of the catalyst at different temperatures in the sulfur-containing and water-containing flue gas atmosphere

Example 12

0.12mL of catalysts 1-9 were placed in a tubular fixed-bed reactor, and the experimental conditions were as follows:

The reaction conditions are: NO: 950ppm, NO ₂ : 50ppm, NH ₃ : 1000ppm, SO ₂ : 100ppm, O ₂ : 3%, H ₂ O: 10(vol)%, N ₂ is the balance gas, and the total gas flow is 120mL /min, the reaction space velocity (GHSV) is 60,000h ^-1 , reacted at 200°C for a long time, within 12 hours, the NO _x conversion rate of catalyst 1 has been maintained at about 98%, and the NO _x conversion rate of catalyst 2 has been maintained At about 94%, the _{NOx conversion} rate of catalyst 3 has been maintained at about 99%, that of catalyst 4 has been maintained at about 97%, that of catalyst 5 _has been maintained at about 99%, and that of catalyst 6 The _NOx conversion rate has been maintained at about 99%, the _NOx conversion rate of Catalyst 7 has been maintained at about 92%, the _NOx conversion rate of Catalyst 8 has been maintained at about 99%, and the _NOx conversion rate of Catalyst 9 has been maintained at 95%. %about.

Comparative example 1

The rest is the same as that of Example 5, except that the molar ratio of Mn to Ti is adjusted to be 1.2:1 by controlling the addition amount of each raw material.

Comparative example 2

The rest are the same as in Example 5, except that the molar ratio of Fe and Ti is adjusted to be 1.2 by controlling the addition of each raw material.

Comparative example 3

The rest are the same as in Example 5, except that the molar ratio of Zr to Ti is adjusted to be 1.2 by controlling the addition of each raw material.

Comparative example 4

The rest are the same as in Example 5, except that the molar ratio of Ce to Ti is adjusted to be 1.2 by controlling the addition amount of each raw material.

Comparative example 5

The rest are the same as in Example 5, except that the molar ratio of Mn to Ti is adjusted to be 0.005 by controlling the addition amount of each raw material.

Comparative example 6

The rest are the same as in Example 5, except that the molar ratio of Fe and Ti is adjusted to be 0.005 by controlling the addition of each raw material.

Comparative example 7

The rest are the same as in Example 5, except that the molar ratio of Zr to Ti is adjusted to be 0.005 by controlling the addition amount of each raw material.

Comparative example 8

The rest are the same as in Example 5, except that the molar ratio of Ce and Ti is adjusted to be 0.005 by controlling the addition amount of each raw material.

0.12mL of the catalysts of Comparative Examples 1-8 were placed in a tubular fixed-bed reactor, and the experimental conditions were as follows: the reaction conditions were: NO: 950ppm, NO ₂ : 50ppm, NH ₃ : 1000ppm, O ₂ : 3%, N ₂ is the balance gas, the total gas flow rate is 120mL/min, and the reaction space velocity (GHSV) is 60,000h ^-1 . The reaction range is from 100°C to 200°C. The reaction results are shown in Table 3:

Table 3 The nitrogen oxide conversion rate of the catalyst at different temperatures in a clean flue gas atmosphere

0.12mL of the catalysts of Comparative Examples 1-8 were placed in a tubular fixed-bed reactor, and the experimental conditions were as follows:

The reaction conditions are: NO: 950ppm, NO ₂ : 50ppm, NH ₃ : 1000ppm, O ₂ : 3%, SO ₂ : 100ppm, H ₂ O: 10vol%, N ₂ is the balance gas, the total gas flow rate is 120mL/min, The reaction space velocity (GHSV) is 60,000h ^-1 , the reaction temperature range is 100-200°C, and the reaction results are shown in Table 4:

Table 4 Nitrogen oxide conversion rates of catalysts at different temperatures in sulfur-containing and water-containing flue gas atmospheres

The catalysts of Comparative Examples 1-8 were placed in a tubular fixed-bed reactor, and the experimental conditions were as follows:

The reaction conditions are: NO: 950ppm, NO ₂ : 50ppm, NH ₃ : 1000ppm, SO ₂ : 100ppm, O ₂ : 3%, H ₂ O: 10(vol)%, N ₂ is the balance gas, and the total gas flow is 120mL /min, the reaction space velocity (GHSV) is 60,000h ^-1 , reacted at 200°C for a long time, within 12 hours, the catalyst _NOx conversion rate of Comparative Example 1 was maintained at about 80%, and the catalyst NOx conversion rate of Comparative Example 2 was maintained at about 80%. _x conversion rate has been maintained at about 88%, the _NOx conversion rate of the catalyst of comparative example 3 has been maintained at about 84%, the _NOx conversion rate of the catalyst of comparative example 4 has been maintained at about 67%, and the catalyst of comparative example 5 has been maintained at about 67%. The _NOx conversion rate has been maintained at about 65%, the _NOx conversion rate of the catalyst of Comparative Example 6 has been maintained at about 72%, the _NOx conversion rate of the catalyst of Comparative Example 7 has been maintained at about 88%, and the catalyst of Comparative Example 8 has been maintained at about 88%. The _NOx conversion rate has been maintained at around 69%.

From the comparison of the catalytic performance of the catalysts of the above comparative examples 1 to 8, it can be known that the molar ratio of manganese element to Ti element and the molar ratio of each metal in the auxiliary agent to Ti element are important parameters affecting the catalytic performance of the catalyst. Mn The /Ti molar ratio is 0.01 to 1.0, preferably 0.01 to 0.5, and the molar ratio of each metal in the additive to Ti is independently 0.01 to 1.0, preferably 0.01 to 0.5. Compared with other ranges, the catalytic performance of the catalyst is remarkable improve.

Comparative example 9

The rest are the same as in Example 5, except that no titanium source is added to obtain a catalyst in which the main component of the catalyst is manganese oxide.

Comparative example 10

The rest is the same as in Example 5, except that no manganese source is added to obtain a catalyst in which the main component of the catalyst is titanium oxide.

Comparative example 11

The rest is the same as in Example 5, except that no iron source is added to obtain a catalyst whose catalyst component is a titanium-manganese-zirconium-cerium composite oxide.

Comparative example 12

The rest is the same as in Example 5, except that no zirconium source is added to obtain a catalyst whose catalyst component is a titanium-manganese-iron-cerium composite oxide.

Comparative example 13

The rest is the same as in Example 5, except that no cerium source is added to obtain a catalyst whose catalyst component is a titanium-manganese-iron-zirconium composite oxide.

Place 0.12mL of the catalysts of Comparative Examples 9-13 in a tubular fixed-bed reactor, and the experimental conditions are as follows: the reaction conditions are: NO: 950ppm, NO ₂ : 50ppm, NH ₃ : 1000ppm, O ₂ : 3%, N ₂ is the balance gas, the total gas flow rate is 120mL/min, and the reaction space velocity (GHSV) is 60,000h ^-1 . The reaction range is from 100°C to 200°C. The reaction results are shown in Table 5:

Table 5 Nitrogen oxide conversion rate of catalyst at different temperatures in clean flue gas atmosphere

0.12mL of the catalysts of Comparative Examples 9-13 were placed in a tubular fixed-bed reactor, and the experimental conditions were as follows:

The reaction conditions are: NO: 950ppm, NO ₂ : 50ppm, NH ₃ : 1000ppm, O ₂ : 3%, SO ₂ : 1000ppm, H ₂ O: 10vol%, N ₂ is the balance gas, the total gas flow rate is 120mL/min, The reaction space velocity (GHSV) is 60,000h ^-1 , the reaction temperature range is 100-200°C, and the reaction results are shown in Table 6:

Table 6 The conversion rate of nitrogen oxides of the catalyst at different temperatures in the sulfur-containing and water-containing flue gas atmosphere

The catalysts of Comparative Examples 9-13 were placed in a tubular fixed-bed reactor, and the experimental conditions were as follows:

The reaction conditions are: NO: 950ppm, NO ₂ : 50ppm, NH ₃ : 1000ppm, SO ₂ : 100ppm, O ₂ : 3%, H ₂ O: 10(vol)%, N ₂ is the balance gas, and the total gas flow is 120mL /min, the reaction space velocity (GHSV) is 60,000h ^-1 , reacted at 200°C for a long time, within 12 hours, the NOx conversion rate of the catalyst of Comparative Example 9 was maintained at about 88%, and the catalyst of Comparative Example 10 was The NOx conversion rate has been maintained at about 60%, the NOx conversion rate of the catalyst in Comparative Example 11 has been maintained at about 84%, the NOx conversion rate of the catalyst in Comparative Example 12 has been maintained at about 88%, and the NOx conversion rate of the catalyst in Comparative Example 13 has been maintained at about 84%. The rate has been maintained at around 76%.

Through comparison of the catalytic properties of the catalysts of Comparative Examples 9 to 13, it can be known that in the present invention, there is a synergistic effect between titanium dioxide, manganese oxides and the metals in the additives, and the present invention utilizes the above-mentioned synergistic effect. , a catalyst with excellent performance was obtained.

Comparative example 14

Comparative Example 14 is the catalyst disclosed in Example 1 of CN1724149A, which uses titanium dioxide as a carrier and two or more variable-valence metals or oxides as catalyst promoters.

Comparative example 15

Comparative Example 15 is the catalyst disclosed in Example 1 of CN103182312A, which uses _TiO2 as a carrier and supports oxides of Mn, Ce and Nb.

Comparative example 16

Comparative example 16 is the MnO _x /TiNT catalyst disclosed by Yao Yao et al.

Comparative example 17

Comparative Example 17 is the _{MnO x -SnO 2} / _{TiO 2} catalyst disclosed _by Deng Shanshan et al.

Comparative example 18

Comparative Example 18 is the catalyst disclosed in Example 2 of CN1724149A.

0.12mL of the catalysts of Comparative Examples 14-18 were placed in a tubular fixed-bed reactor, and the experimental conditions were as follows: the reaction conditions were: NO: 950ppm, NO ₂ : 50ppm, NH ₃ : 1000ppm, O ₂ : 3%, N ₂ is the balance gas, the total gas flow rate is 120mL/min, and the reaction space velocity (GHSV) is 60,000h ^-1 . The reaction range is from 100°C to 200°C. The reaction results are shown in Table 7:

Table 7 The nitrogen oxide conversion rate of the catalyst at different temperatures in a clean flue gas atmosphere

0.12mL of the catalysts of Comparative Examples 14-18 were placed in a tubular fixed-bed reactor, and the experimental conditions were as follows:

The reaction conditions are: NO: 950ppm, NO ₂ : 50ppm, NH ₃ : 1000ppm, O ₂ : 3%, SO ₂ : 100ppm, H ₂ O: 10vol%, N ₂ is the balance gas, the total gas flow rate is 120mL/min, The reaction space velocity (GHSV) is 60,000h ^-1 , the reaction temperature range is 100-200°C, the NOx conversion rate of the catalyst in Comparative Example 14 has been maintained at about 81%, and the NOx conversion rate of the catalyst in Comparative Example 15 has been maintained at Above 80%, the NOx conversion rate of the catalyst of Comparative Example 16 has been maintained at about 75%, the NOx conversion rate of the catalyst of Comparative Example 17 has been maintained at about 75%, and the _NOx conversion rate of the catalyst of Comparative Example 18 has been maintained at 78%. %about.

The catalysts of Comparative Examples 14-18 were placed in a tubular fixed-bed reactor, and the experimental conditions were as follows:

The reaction conditions are: NO: 950ppm, NO ₂ : 50ppm, NH ₃ : 1000ppm, SO ₂ : 100ppm, O ₂ : 3%, H ₂ O: 10(vol)%, N ₂ is the balance gas, and the total gas flow is 120mL /min, the reaction space velocity (GHSV) is 60,000h ^-1 , reacted at 200°C for a long time, within 12 hours, the NOx conversion rate of the catalyst of Comparative Example 14 was maintained at about 85%, and the catalyst of Comparative Example 15 was The NOx conversion rate has been maintained at about 80%, the NOx conversion rate of the catalyst in Comparative Example 16 has been maintained at about 85%, the NOx conversion rate of the catalyst in Comparative Example 17 has been maintained at about 90%, and the NOx conversion rate of the catalyst in Comparative Example 18 has been maintained at about 80%. The rate has been maintained at around 87%.

Comparative example 19

Comparative Example 19 is the iron-cerium-titanium composite oxide catalyst disclosed in Example 1 of CN103071506A.

Comparative example 20

Comparative Example 20 is the catalyst Ce ₄ VWTi disclosed in Example 1 of CN102764643.

Comparative example 21

Comparative Example 21 is the catalyst 3%V ₂ O ₅ -2% ZrO ₂ /10% WO ₃ -TiO ₂ disclosed in Example 2 of CN103252232A.

Comparative example 22

Comparative Example 22 is the cerium-zirconium-tungsten composite oxide catalyst disclosed in Example 1 of CN103240079A.

Comparative example 23

Comparative Example 23 is the molybdenum-cerium-zirconium composite oxide catalyst disclosed in Example 1 of CN103816891.

Comparative example 24

Comparative Example 24 is the niobium-cerium-zirconium composite oxide catalyst disclosed in Example 1 of CN104368329A.

Comparative example 25

Comparative Example 25 is the manganese-cerium-titanium-iron catalyst disclosed in Example 2 of CN103055848A.

0.12mL of the catalysts of Comparative Examples 19-25 were placed in a tubular fixed-bed reactor, and the experimental conditions were as follows:

The reaction conditions are: NO: 950ppm, NO ₂ : 50ppm, NH ₃ : 1000ppm, O ₂ : 3%, SO ₂ : 1000ppm, H ₂ O: 10vol%, N ₂ is the balance gas, the total gas flow rate is 120mL/min, The reaction space velocity (GHSV) is 60,000h ^-1 , the reaction temperature range is 100-200°C, and the reaction results are shown in Table 8:

Table 8 The conversion rate of nitrogen oxides of the catalyst at different temperatures in the sulfur-containing and water-containing flue gas atmosphere

In summary, the catalyst of the present invention is mainly composed of titanium dioxide and manganese oxide, and the auxiliary agent is any three or at least four of copper, zirconium, molybdenum, iron, nickel, cerium, cobalt, tungsten or niobium oxide The combination of the obtained catalyst has the ability to resist low-concentration SO ₂ poisoning and water vapor poisoning, and the catalyst has good stability and can adapt to high space velocity. And, the present invention adopts co-precipitation method, uses sodium carbonate or ammonia water or urea as precipitation agent. The method has economical preparation steps, low cost, simple operation process and mild conditions.

It will be apparent to those skilled in the art that the invention is not limited to the details of the above-described exemplary embodiments, but that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Accordingly, the embodiments should be regarded in all points of view as exemplary and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and it is therefore intended that the scope of the invention be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents of the elements are embraced in the present invention.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only includes an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

The applicant declares that the present invention illustrates the detailed methods of the present invention through the above-mentioned examples, but the present invention is not limited to the above-mentioned detailed methods, that is, it does not mean that the present invention can only be implemented depending on the above-mentioned detailed methods. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the scope of protection and disclosure of the present invention.

Claims (10)

1. a denitrating flue gas powder catalyst, comprise titanium dioxide, manganese oxide and auxiliary agent, auxiliary agent is the combination of any more than three kinds or three kinds in Cu oxide, Zirconium oxide, molybdenum oxide, cerium oxide, ferriferous oxide, nickel oxide, cobalt/cobalt oxide, tungsten oxide or niobium oxide.

2. catalyst as claimed in claim 1, it is characterized in that, the mol ratio of Mn element and Ti element is (0.01 ~ 1.0), preferably 0.01 ~ 0.5;

Preferably, in auxiliary agent, the mol ratio of each metal and titanium element is (0.01 ~ 1.0) all independently, preferably 0.01 ~ 0.5.

3. a preparation method for the denitrating flue gas powder catalyst as described in one of claim 1-2, prepares denitrating flue gas powder catalyst by coprecipitation.

4. method as claimed in claim 3, is characterized in that, said method comprising the steps of:

(1) combination of any more than three kinds or three kinds taken in soluble copper source, zirconium source, molybdenum source, cerium source, source of iron, nickel source, cobalt source, tungsten source or niobium source solution joins in soluble titanium source and manganese source solution, mix, obtain metal mixed solution;

(2) metal mixed solution is mixed with precipitant solution, control the temperature of mixed solution, pH value, mixing speed and time, make precipitation by metallic ion complete, then static aging, the precipitation suspension obtained is separated and obtains filter cake, washing, dry, roasting, obtains denitrating flue gas powder catalyst.

5. method as claimed in claim 4, is characterized in that, described titanium source is selected from the mixture of any one or at least two kinds in titanium tetrachloride, metatitanic acid, titanyl sulfate or butyl titanate;

Preferably, described manganese source is selected from the mixture of any one or at least two kinds in manganese nitrate, manganese acetate or manganese chloride;

Preferably, described copper source is selected from the mixture of any one or at least two kinds in copper nitrate, copper chloride or copper sulphate;

Preferably, described zirconium source is selected from the mixture of any one or at least two kinds in zirconium nitrate, zirconium oxychloride, acetic acid zirconium or zirconium sulfate;

Preferably, described molybdenum source is selected from ammonium molybdate or/and sodium molybdate;

Preferably, described cerium source is selected from the mixture of any one or at least two kinds of cerous nitrate, cerous sulfate or cerous chlorate;

Preferably, described source of iron is selected from the mixture of any one or at least two kinds in ferric nitrate, iron chloride, ferric sulfate or ferric phosphate;

Preferably, described nickel source is selected from the mixture of any one or at least two kinds in nickel nitrate, nickel acetate or nickel chloride;

Preferably, described cobalt source is selected from the mixture of any one or at least two kinds in cobalt nitrate, cobalt chloride, cobalt acetate or cobalt oxalate;

Preferably, described tungsten source is selected from the mixture of any one or at least two kinds in ammonium tungstate, potassium tungstate or sodium tungstate;

Preferably, described niobium source is selected from columbium pentachloride or/and niobium oxalate.

6. the method as described in claim 4 or 5, is characterized in that, described precipitating reagent is the mixture of any one or at least two kinds in sodium carbonate, ammoniacal liquor or urea;

Preferably, metal mixed solution is added drop-wise in precipitant solution by step (2), or precipitant solution is added drop-wise in metal mixed solution;

Preferably, when adopting sodium carbonate or ammoniacal liquor to be precipitating reagent, the temperature controlling mixed solution is 0 ~ 40 DEG C, and when adopting urea to be precipitating reagent, the temperature controlling mixed solution is 80 ~ 100 DEG C;

Preferably, control the pH value of mixed solution 6 ~ 12, preferably 8 ~ 11;

Preferably, control mixing time is 1 ~ 10h, preferably 2 ~ 4h;

Preferably, controlling mixing speed is 100 ~ 4000 revs/min, preferably 600 ~ 1000 revs/min.

7. the method as described in one of claim 4-6, is characterized in that, described standing ageing time is 1 ~ 24h, preferably 6 ~ 12h;

Preferably, the precipitation suspension suction filtration obtained is obtained filter cake;

Preferably, deionized water or distilled water is adopted to wash, washing times 2 ~ 4 times, preferably 3 times.

8. the method as described in one of claim 4-7, is characterized in that, the temperature of described drying is 80 ~ 120 DEG C, preferably 100 ~ 120 DEG C;

Preferably, described drying time is 3 ~ 24h, preferably 8 ~ 12h.

9. the method as described in one of claim 4-8, is characterized in that, described sintering temperature is 400 ~ 600 DEG C, preferably 500 DEG C;

Preferably, described roasting time is 4 ~ 8h, preferred 5h.

10. a purposes for the denitrating flue gas powder catalyst as described in one of claim 1-2, described catalyst is used for the purification of nitrogen oxides of stationary source and moving source.