CN103769233B - Catalyst carrier and preparation method and the catalyst prepared by this carrier and application thereof - Google Patents

Abstract

The invention provides catalyst carrier and preparation method and the catalyst prepared by this carrier and application thereof.The present invention adopts the activated alumina of multiple crystalline phase and kind, comprises γ-A1 ₂o ₃, ρ-A1 ₂o ₃, α-A1 ₂o ₃, κ-A1 ₂o ₃with θ-A1 ₂o ₃in one or more mixtures, preferred γ-A1 ₂o ₃, ρ-A1 ₂o ₃, α-A1 ₂o ₃in one, two or three mixture, to replace or part replaces the hydrate (i.e. aluminium hydroxide) of aluminium oxide as one of raw material preparing carrier, prepare the carrier of silver catalyst.Thus the performance of carrier that obtains of method be improved significantly.This carrier is after load silver and various active constituent make silver catalyst, and produce at ethylene in the process of oxirane and demonstrate good activity and selectivity, especially selective tool has clear improvement.

Description

Catalyst carrier and preparation method and the catalyst prepared by this carrier and application thereof

Technical field

The present invention relates to catalyst field, be specifically related to a kind of silver catalyst carrier and preparation method thereof, and the catalyst be made up of it and application; Relate more specifically to a kind of produce the alumina support of oxirane silver catalyst for ethylene preparation method and the carrier be made up of the method and obtained silver catalyst and application.

Background technology

Under silver catalyst effect, ethylene mainly generates oxirane, side reaction occurs simultaneously and generates carbon dioxide and water etc.The main performance index of silver catalyst comprises its active, selective and stability.Wherein activity generally refers to the reaction temperature that process for ethylene oxide production reaches required when necessarily reacting load; Desired reaction temperature is lower, and the activity of catalyst is higher.Selectively refer to that in reaction, ethylene conversion becomes the ratio of the molal quantity of oxirane and the overall reaction molal quantity of ethene.Stability is then the fall off rate of activity and selectivity, and the stability of fall off rate more small catalyst is better.Produce at ethylene in the process of oxirane and use high activity, high selectivity and the silver catalyst that has good stability greatly to increase economic efficiency, therefore manufacture the Main way that such silver catalyst is silver catalyst research.The performance of silver catalyst is except having important relationship with the composition of catalyst and preparation method, and performance of the carrier also used with catalyst and preparation method thereof has important relationship.

The preparation method of silver catalyst be mainly the preparation and administration to active component of porous carrier (as aluminium oxide) and auxiliary agent to as described in this two processes on carrier.Its carrier generally selects the Alpha-alumina that specific area is less.Aluminium oxide (Al ₂o ₃) be a kind of catalyst carrier of having many uses, its kind is very many, and its crystal structure, surface catalysis performance are also very complicated, directly affect the performance of silver catalyst.

Carrier needs to provide certain area load active component, and active component is thereon dispersed, and this just proposes very high requirement to the pore structure of carrier.The hole of alumina support can be divided into three types: the first, primary particle intercrystalline hole, the mainly dewatering hole of alumina raw material crystal grain, be substantially 1-2nm size parallel-plate face between gap; The second, hole between alumina raw material offspring, changing with the effusion of moisture and crystalline phase change in roasting, is hole more than tens nanometer; The third, pore creating material and carrier shaping time produce defective hole and macropore.The pore structure of carrier can impact physical property, and then affects the performance of catalyst.

The primary raw material generally preparing alumina support is the hydrate of aluminium oxide, i.e. aluminium hydroxide, hydrated alumina dehydration can produce Louis (L) Acid and basic sites, and these L acid sites are easy to water suction and change proton (B) Acid and basic sites into.The crystal formation kind of aluminium oxide is a lot, and impurity and moisture impact more or less in addition, causes the surface physics of aluminium oxide, chemical property all very complicated.For the α-Al that silver catalyst is selected ₂o ₃although its surface only has the Acid and basic sites of seldom amount, their meetings and active component acting in conjunction, impel ethylene conversion to be oxirane.

In general, the main method preparing silver catalyst carrier is, binding agent and various additives etc. are added by alumina powder raw material, even through batch mixing and kneading, then extrusion molding is difform base substrate, as Raschig ring, spheric granules, porous cylindrical, the shape of a saddle etc., final high temperature sintering makes the alpha-alumina supports product of porous heat-resistant, specifically can see patent documents such as US5063195, US5703001 and US5801259.

The improvement that the activity and selectivity of these methods above-mentioned to carrier property and catalyst brings is also very limited, therefore this area still needs to improve carrier and manufacture method thereof, be beneficial to produce the better silver catalyst of performance, especially selective better catalyst.

In view of the situation of above-mentioned prior art, the present inventor has carried out research extensively and profoundly at silver catalyst and alumina support field thereof, found that, replace or partly replace the hydrate (i.e. aluminium hydroxide) of aluminium oxide as the raw material preparing carrier with the activated alumina of different crystalline phase and kind, the pore structure of finished product carrier can be adjusted, the loading type silver catalyst be made up of this carrier, when the oxidation epoxy ethane for catalyzed ethylene, selectively obviously to be improved.

Summary of the invention

The object of the present invention is to provide a kind of catalyst carrier and preparation method thereof, the carrier be made up of the method, after load silver and various active constituent make silver catalyst, is produced at ethylene in the process of oxirane and is demonstrated good activity and selectivity.The present invention also provides the alumina support prepared by the method to be a kind of silver catalyst of carrier.

The invention provides a kind of catalyst carrier, comprising:

A) porous A1 ₂o ₃, it comprises α-A1 ₂o ₃, described α-A1 ₂o ₃weight content be at least 85 ~ 99.9% of total weight of carrier, preferably at least 90 ~ 99.9%; With

B) one or more alkaline-earth metal and/or alkaline earth metal compound, it is 0.01-15wt% that its metallic element weight accounts for total weight of carrier content, preferred 0.1-3wt%.

Described catalyst carrier is a kind of porous A1 of modification ₂o ₃carrier.

Described porous A1 ₂o ₃preferred external diameter is 7-9mm, and honeycomb aperture is the cellular cylindrical α-A1 in the seven apertures in the human head of 1-3mm, five holes or three holes ₂o ₃particle, or external diameter be 7-9mm, internal diameter is the circular α of the single hole-A1 of 3-6mm ₂o ₃particle.

One or more in described alkaline-earth metal preferably magnesium, calcium, strontium and barium, more preferably strontium and/or barium; One or more in the oxide of described alkaline earth metal compound preferred bases earth metal, sulfate, acetate, nitrate, carbonate and oxalates, one or more more preferably in barium monoxide, barium sulfate, barium nitrate and brium carbonate.

The crushing strength of catalyst carrier of the present invention is more than 20N/ grain, and specific area is 0.2-5.0m ²/ g, water absorption rate>=30%, pore volume is 0.35-0.85ml/g; Preferred crush strength is 40-200N/ grain, and specific area is 0.5-2.0m ²/ g, water absorption rate>=45%, and pore volume is 0.40-0.8ml/g.

In carrier of the present invention, aluminium oxide should account for the overwhelming majority; Typically, based on the gross weight of carrier, alumina content is at least 90wt%.In addition, when by raw alumina roasting, and not all aluminium oxide all can be transformed into α-A1 ₂o ₃; Therefore, in carrier of the present invention, based on A1 ₂o ₃gross weight, α-A1 ₂o ₃content be generally at least 85wt%, preferably at least 90wt%.α-A1 of the present invention ₂o ₃carrier needs to obtain porous material by high temperature sintering usually.In carrier of the present invention, the alkaline-earth metal of components b is modified component, and the existence of these components makes the loading type silver catalyst be made up of this carrier produce the effect improved when catalyzed ethylene epoxy ethane, and this comprises the activity and selectivity improving catalyst.

The invention provides a kind of preparation method of above-mentioned carrier, comprise the steps:

Step one, forms the mixture comprising following component:

I) active A 1 ₂o ₃powder or A1 ₂o ₃powder and 50 order-500 object three water A1 ₂o ₃mixture;

Described active A 1 ₂o ₃powder content is based on component i) gross weight more than 1%, be preferably more than 10%, be more preferably 100%;

Preferred described A1 ₂o ₃a1 in powder ₂o ₃content higher than 99%, more preferably higher than 99.9%.

Ii) by the vacation one water A1 of 200 mesh sieves ₂o ₃;

Iii) one or more alkaline-earth metal and/or its compound;

Iv) based on the gross weight of component i and ii be the mineralizer of 0.01-5.0wt%, preferred 1-4wt%;

V) binding agent; And

Vi) water;

Step 2, by shaping and dry for the mixture obtained in step one, then obtains described catalyst carrier by its roasting.

After each component mixing in step one, usually obtain paste.By shaping through step 2 for gained paste, preferred extrusion molding, obtains formed body, i.e. carrier blank.

In step 2, this formed body is dry at temperature is 80-200 DEG C.The shape of gained formed body can be annular, spherical, cylindricality or porous column shape, or other shape.Preferably more than 15 minutes described drying time.

The roasting at 1100-1600 DEG C, preferably 1200-1500 DEG C of dried formed body.Carrier is made to have enough intensity and good surface property.Under the highest sintering temperature, usually carrier is incubated more than 1 hour.Aluminium oxide is made substantially all to be converted into α-A1 by roasting ₂o ₃, obtain porous alumina carrier thus.

In above-mentioned preparation method,

In above-mentioned carrier, the component i described in step one and the weight ratio of component ii are 0.1 ~ 16:1, are preferably 1 ~ 6:1.

Component i described in step one in preparation method of the present invention) in active A 1 ₂o ₃the active A 1 of different crystalline phase and kind can be selected ₂o ₃powder or various active A 1 ₂o ₃the mixture of powder, usually in solidapowder form, and requires A1 in powder ₂o ₃content higher than 99%, preferably higher than 99.9%.

Active A 1 described in step one ₂o ₃powder is selected from γ-A1 ₂o ₃, ρ-A1 ₂o ₃, α-A1 ₂o ₃, κ-A1 ₂o ₃with θ-A1 ₂o ₃powder, and other various A1 ₂o ₃one or more mutually; Preferred γ-A1 ₂o ₃, ρ-A1 ₂o ₃, α-A1 ₂o ₃one in powder, two or three.

Owing to adopting the activated alumina of multiple crystalline phase and kind to replace or partly replacing the hydrate (i.e. aluminium hydroxide) of aluminium oxide as one of raw material preparing carrier, the performance of finished product carrier is improved, the loading type silver catalyst be made up of this carrier, when the oxidation epoxy ethane for catalyzed ethylene, selectively obviously to be improved.

Component ii described in step one) usually also in solidapowder form.

Component iii described in step one) described alkaline-earth metal be selected from magnesium, calcium, strontium and barium one or more, alkaline earth metal compound is selected from the oxide of alkaline-earth metal, sulfate, acetate, nitrate, carbonate and oxalates; One or more in preferred use barium monoxide, barium sulfate, barium nitrate, brium carbonate.

Component iv described in step one) described mineralizer is fluoride, is preferably inorganic fluoride, is more preferably one or more in hydrogen fluoride, ammonium fluoride, aluminum fluoride, magnesium fluoride and ice crystal (hexafluoro sodium aluminate).

In carrier of the present invention, also need to use component v) binding agent, as added acid as bonding agent, it generates Alumina gel with the vacation one Water oxidize aluminium in mixture, each component is bonded together, becomes plastic paste, such as becoming can the paste of extrusion molding.

Component v described in step one) described in bonding agent in comprise acid, one or more in the preferred nitric acid of described acid, formic acid, acetic acid, propionic acid and hydrochloric acid, more preferably nitric acid and/or acetic acid.When described acid is aqueous solution of nitric acid, the weight ratio of nitric acid and water is 1:1.25 ~ 10, preferred 1:2 ~ 8.In addition, available Alumina gel partly or entirely replaces a false water A1 described in acid described in component v and component ii ₂o ₃.

Component v described in step one) consumption of binding agent is conventional, as long as each component can be bonded together, and forms paste.Typically, the consumption of binding agent is based on component i), ii), iii) and gross weight 15-60wt% iv), preferred 15-50wt%.

In support preparation method of the present invention, the mineralizer iv described in step one) to add be transformation of crystal in order to accelerated oxidation aluminium.

The present invention also provides a kind of silver catalyst, and this catalyst comprises:

1) catalyst carrier;

2) deposition silver on this carrier;

3) alkali metal and/or alkaline-earth metal or the compound based on alkali metal and/or alkaline-earth metal;

4) rhenium metal and/or the compound based on rhenium; And

5) the collaborative auxiliary element of rhenium, it is selected from one or more metals in chromium, molybdenum, tungsten and boron, and/or is selected from the compound based on one or more elements in chromium, molybdenum, tungsten and boron.

Wherein, described alkali metal be selected from lithium, sodium, potassium, rubidium and caesium one or more; Preferred caesium and/or potassium, most preferably be caesium;

Described alkaline-earth metal be selected from magnesium, calcium, strontium and barium one or more, preferred strontium and/or barium;

The described compound based on one or more elements in chromium, molybdenum, tungsten and boron is the collaborative auxiliary agent of rhenium.

Silver catalyst of the present invention can be prepared in the usual way, such as, by preparing with the solution impregnation of a kind of Ag-containing compound and organic amine carrier provided by the invention.In the present invention, the collaborative auxiliary agent of alkali metal, alkaline-earth metal, rhenium and rhenium independently of one another before dipping silver, be applied in porous alpha-alumina supports while load silver or after load silver, or is immersed in porous alpha-alumina supports after silver compound is reduced; Preferably load while load silver.

In silver catalyst of the present invention, on the surface that silver is dispersed in porous refractory alumina support and in hole.Because high silver content can increase the cost of catalyst, reduce economy.Therefore, in a preferred embodiment of silver catalyst of the present invention, based on the gross weight of silver catalyst, the weight content of silver is 1-35%, preferred 5-30%; The weight content of alkali metal is 5-2000ppm, is preferably 10-1500ppm; The weight content of alkali earth metal is 10-40000ppm, is preferably 800-25000ppm; The weight content of rhenium element is 5-1500ppm, is preferably 10-1000ppm; The weight content of the collaborative auxiliary element of rhenium is 5-1000ppm, is preferably 10-500ppm.

In one embodiment of the invention, the preparation method of silver catalyst of the present invention comprises the steps: the first step, by the solution impregnation porous alpha-alumina supports of the present invention of the collaborative auxiliary agent containing the silver compound of q.s, organic amine, optional alkali metal promoter, optional base earth metal promoter and optional rhenium auxiliary agent and optional rhenium; Second step, leaching maceration extract; With the 3rd step, in air or inert gas, second step gained carrier is activated, make described silver catalyst.

In order to prepare silver catalyst of the present invention, silver compound used can for being suitable for any silver compound preparing ethylene oxide silver catalyst.The present invention preferably uses silver oxide, silver nitrate and/or silver oxalate.

In order to prepare catalyst of the present invention, organic amine compound used can for being suitable for any organic amine compound preparing ethylene oxide silver catalyst, as long as this organic amine compound can form argent-amine complex with silver compound.For the purpose of the present invention, pyridine, butylamine, ethylenediamine, 1,3-propane diamine, monoethanolamine or its mixture is preferably used, the mixture of such as ethylenediamine and monoethanolamine.

In order to prepare catalyst of the present invention, the optional alkali metal promoter used can be compound (as nitrate, sulfate and hydroxide) or its mixture of lithium, sodium, potassium, rubidium or caesium, preferred cesium nitrate, lithium nitrate and/or potassium hydroxide.

In order to prepare catalyst of the present invention, the base earth metal promoter of optional use can be one or more in the compound of magnesium, calcium, strontium and barium, as as described in one or more in the oxide of element, oxalates, sulfate, acetate and nitrate, the compound of preferred barium and/or the compound of strontium, as barium acetate and/or strontium acetate.

In order to prepare catalyst of the present invention, the optional rhenium auxiliary agent used can be oxide, perrhenic acid, the perrhenate of rhenium, or its mixture, preferred perrhenic acid and/or perrhenate, such as perrhenic acid, perrhenic acid caesium and/or ammonium perrhenate etc.In dipping solution except silver compound, organic amine, optional alkali metal promoter, optional base earth metal promoter and optional rhenium auxiliary agent, the coassist agent of rhenium auxiliary agent can also be added, to improve the activity of gained silver catalyst, selective and stability further.The coassist agent of the rhenium auxiliary agent in the present invention can be selected from chromium, molybdenum, tungsten and boron compound one or more.

In the impregnation step, for ensureing all even abundant load of silver, carrier preferably vacuumizes in advance.

After porous alpha-alumina supports dipping argentiferous maceration extract, leaching maceration extract, then in air or inert gas to step 3) in activate through the carrier of dipping.For this reason, the carrier through dipping can be activated in the moving air of 180-700 DEG C, preferably 200-500 DEG C or inert gas are as the air-flow such as nitrogen, argon gas, soak time at least 2 minutes usually, such as 2-120 minute, preferred 2-60 minute.For ensureing that catalyst has higher activity, this activation temperature should higher than 500 DEG C.

In a preferred embodiment of preparation silver catalyst of the present invention, first the aqueous solution of silver nitrate and ammonium oxalate or oxalic acid aqueous solution is made to react, separate out silver oxalate precipitate, after filtration, spend deionized water, until without nitrate ion, after drying, silver oxalate is dissolved in organic amine as in the aqueous solution of pyridine, butylamine, ethylenediamine, 1,3-propane diamine, monoethanolamine or its mixture, add each auxiliary agent, be made into dipping solution; Then porous alpha-alumina supports 10-60 minute of the present invention is flooded to be less than the condition of 10mmHg in vacuum with gained dipping solution under, drain, in the temperature range of 200-500 DEG C, 1-120 minute is kept, preferred 2-60 minute, to activate in air or inert gas.Also can replace silver nitrate with silver oxide, silver oxalate also can not analyse filter, direct and organic amine complexing, then impregnated carrier.

The present invention also provides above-mentioned carrier, carrier prepared by said method or above-mentioned silver catalyst to produce the application in oxirane at ethylene.The stable performance of the silver catalyst be made up of carrier of the present invention, and there is higher activity and selectivity, be specially adapted to the reaction that ethylene produces oxirane.

Detailed description of the invention

The mensuration of catalyst performance:

Various silver catalyst laboratories of the present invention microreactor evaluating apparatus tests its activity and selectivity.The reactor used in microreactor evaluating apparatus is the stainless steel reaction pipe of internal diameter 4mm, and reaction tube is placed in heating jacket.The admission space of catalyst is 1ml, and inert filler is arranged at bottom, makes beds be positioned at the flat-temperature zone of heating jacket.

The condition determination of the activity and selectivity that the present invention adopts is as follows:

METHOD FOR CONTINUOUS DETERMINATION reactor inlet and exit gas composition after above-mentioned reaction condition is reached when stable.Measurement result calculates selective as follows after carrying out volume contraction correction:

Wherein, EO is reactor outlet gas and inlet gas ethylene oxide concentration difference, CO ₂be that in reactor outlet gas and inlet gas, gas concentration lwevel is poor, get the result of the test of average as the same day of more than 10 groups test datas.

The present invention is described further below in conjunction with embodiment, but scope of the present invention is not limited to these embodiments.

Comparative example 1

By 50-500 object three water A1 ₂o ₃400g, crosses the vacation one water A1 of 200 mesh sieves ₂o ₃100g, ammonium fluoride 10g, BaSO ₄3g, puts into blender and mixes, and proceeds in kneader, adds 20 % by weight aqueous solution of nitric acid 100 milliliters, and being kneaded into can the paste of extrusion molding.Extrusion molding is the single hole column of external diameter 8.0mm, long 6.0mm, internal diameter 1.0mm, and at 80-120 DEG C, drying 2 hours, makes free water content be reduced to less than 10 % by weight, obtain green compact.Then green compact are put into electric furnace, be elevated to 1400 DEG C from room temperature, and constant temperature 2 hours at such high temperatures, obtain white α-A1 ₂o ₃support samples, is called comparison vehicle 1.

The preparation of carrier:

Embodiment 1

By α-A1 ₂o ₃powder 400g, crosses the vacation one water A1 of 200 mesh sieves ₂o ₃100g, ammonium fluoride 10g, BaSO ₄3g puts into blender and mixes, and proceeds in kneader, adds 20 % by weight aqueous solution of nitric acid 100 milliliters, and being kneaded into can the paste of extrusion molding.Extrusion molding is the five hole columns of external diameter 8.0mm, long 6.0mm, internal diameter 1.0mm, and at 80-120 DEG C, drying 2 hours, makes free water content be reduced to less than 10 % by weight, obtain green compact.Then green compact are put into electric furnace, be elevated to 1400 DEG C from room temperature, and constant temperature 2 hours at such high temperatures, obtain white α-A1 ₂o ₃support samples, is called invention carrier 1.

Embodiment 2

The preparation of invention carrier 2 is similar to the preparation of invention carrier 1, only by " α-A1 in carrier embodiment 1 ₂o ₃powder 400g " change " γ-A1 into ₂o ₃powder 400g ".

Embodiment 3

The preparation of invention carrier 3 is similar to the preparation of invention carrier 1, only by " α-A1 in carrier embodiment 1 ₂o ₃powder 400g " change " ρ-A1 into ₂o ₃powder 400g ".

Embodiment 4

The preparation of invention carrier 4 is similar to the preparation of invention carrier 1, only by " α-A1 in carrier embodiment 1 ₂o ₃powder 400g " change " α-A1 into ₂o ₃powder 167g, γ-A1 ₂o ₃powder 167g, ρ-A1 ₂o ₃powder 167g ".

Embodiment 5

The preparation of invention carrier 5 is similar to the preparation of invention carrier 1, only by " α-A1 in carrier embodiment 1 ₂o ₃powder 400g " change " α-A1 into ₂o ₃powder 100g, γ-A1 ₂o ₃powder 100g, ρ-A1 ₂o ₃powder 100g, 50-500 object three water A1 ₂o ₃100g ".

Embodiment 6

The preparation of invention carrier 6 is similar to the preparation of invention carrier 1, only by " α-A1 in carrier embodiment 1 ₂o ₃powder 400g " change " α-A1 into ₂o ₃powder 14g, γ-A1 ₂o ₃powder 14g, ρ-A1 ₂o ₃powder 14g, 50-500 object three water A1 ₂o ₃358g ".

Embodiment 7

The preparation of invention carrier 7 is prepared similar to invention carrier 4, only by " BaSO in carrier embodiment 4 ₄3g " change " Sr (AC) into ₂3.5g ".

Its crushing strength, water absorption rate, specific surface and pore volume etc. are measured respectively to above-mentioned comparison vehicle 1 and invention carrier 1-6, the results are shown in table 1.In the present invention, the crushing strength of carrier refers to side crush intensity, is measured by intensity of pressure instrument; Specific area adopts nitrogen physisorption BET method to measure; Water absorption rate is measured by densimetry; And pore volume adopts pressure mercury method to measure.

Table 1

The preparation of catalyst and performance test

Embodiment 8

350g ethylenediamine is added, 140g monoethanolamine in the glass flask that band stirs, and 400g deionized water, obtain mixed liquor.Slowly added in gained mixed liquor by silver oxalate under stirring, temperature remains on 10-25 DEG C, and silver oxalate is all dissolved, and the addition of silver oxalate makes final obtained maceration extract argentiferous 24 % by weight.Add 3.0g cesium nitrate, 1.0g strontium acetate, and 4.5g ammonium perrhenate, then add deionized water and make solution gross mass reach 2000g, make maceration extract, stand-by.

Get comparison vehicle 1 and invention carrier 1-7 100g separately, put into the container that can vacuumize respectively.Be evacuated to low vacuum in 10mmHg, put into above maceration extract wherein, submergence carrier, keep 30 minutes.Leaching afterwards removes unnecessary maceration extract.Heated 5 minutes in the air stream of 250 DEG C by carrier after dipping, cooling, namely make ethylene oxide silver catalyst, they are respectively comparative catalyst 1 and invention catalyst 1-7.

Analyze the respective silver content of the comparative catalyst 1 made and invention catalyst 1-7 and auxiliary agent content, wherein each content is all in metal.

Use microreactor evaluating apparatus to measure the activity and selectivity of each catalyst sample under the described process conditions of " mensuration of catalyst performance " part above, result of the test lists in table 2.

Table 2

As can be seen from Table 2, the reaction temperature (i.e. active temperature) of comparative catalyst 1 is higher than the reaction temperature of catalyst of the present invention, and the selective of comparative catalyst 1 is less than the selective of catalyst of the present invention.Although invention catalyst 7 reaction temperature is close with comparative catalyst, it is selective is higher than comparative catalyst 1.

Embodiment 9

Embodiment 9 is prepared with method similar to Example 8, just with 3.0g potassium nitrate substitute 3.0g cesium nitrate, 0.5g magnesium sulfate substitutes 1g strontium acetate, and to add 1g ammonium tungstate beyond 4.5g ammonium perrhenate again and add deionized water again and make solution gross mass reach 2000g adding, make maceration extract, stand-by.

Get comparison vehicle 1 and invention carrier 1-7 100g separately, put into the container that can vacuumize respectively.Be evacuated to low vacuum in 10mmHg, put into above maceration extract wherein, submergence carrier, keep 30 minutes.Leaching afterwards removes unnecessary maceration extract.Heated 5 minutes in the air stream of 250 DEG C by carrier after dipping, cooling, namely make ethylene oxide silver catalyst, they are respectively comparative catalyst 2 and invention catalyst 8-14.

Analyze the respective silver content of the comparative catalyst 2 made and invention catalyst 8-14 and auxiliary agent content, wherein each content is all in metal.

Use microreactor evaluating apparatus to measure the activity and selectivity of each catalyst sample under the described process conditions of " mensuration of catalyst performance " part above, result of the test lists in table 3.

Table 3

As can be seen from Table 3, the reaction temperature (i.e. active temperature) of comparative catalyst 2 is higher than catalyst of the present invention, and the selective of comparative catalyst 2 is less than the selective of catalyst of the present invention.Although invention catalyst 9 reaction temperature is close with comparative catalyst, it is selective is higher than comparative catalyst 2.

Claims (24)

1. a preparation method for catalyst carrier, comprises the following steps:

Step one, forms the mixture comprising following component:

I) active A 1 ₂o ₃powder or active A 1 ₂o ₃powder and 50 order-500 object three water A1 ₂o ₃mixture, described active A 1 ₂o ₃powder is selected from γ-A1 ₂o ₃, ρ-A1 ₂o ₃, κ-A1 ₂o ₃with θ-A1 ₂o ₃one or more in powder; Described active A 1 ₂o ₃powder content is based on component i) gross weight more than 1%;

Ii) by the vacation one water A1 of 200 mesh sieves ₂o ₃;

Iii) one or more alkaline-earth metal and/or alkaline earth metal compound;

Iv) gross weight based on component i and ii is the mineralizer of 0.01-5.0wt%;

V) binding agent; And

Vi) water;

Step 2, obtains formed body and drying by shaping for the mixture obtained in step one, then its roasting is obtained described catalyst carrier;

According to catalyst carrier prepared by said method, comprising:

A) porous A1 ₂o ₃, it comprises α-A1 ₂o ₃, described α-A1 ₂o ₃weight content be at least 85 ~ 99.9% of total weight of carrier; With

B) one or more alkaline-earth metal and/or alkaline earth metal compound, it is 0.01-15wt% that its metallic element weight accounts for total weight of carrier content.

2. method according to claim 1, is characterized in that, described porous A1 ₂o ₃be selected from external diameter and be 7-9mm and honeycomb aperture is the cellular cylindrical α-A1 in the seven apertures in the human head of 1-3mm, five holes or three holes ₂o ₃particle, or external diameter is 7-9mm and internal diameter is the circular α of the single hole-A1 of 3-6mm ₂o ₃particle.

3. method according to claim 1, is characterized in that, described alkaline-earth metal is selected from one or more in magnesium, calcium, strontium and barium.

4. method according to claim 3, is characterized in that, described alkaline-earth metal is selected from strontium and/or barium.

5. method according to claim 1, is characterized in that, the crushing strength of described catalyst carrier is more than 20N/ grain; Specific area is 0.2-5.0m ²/ g; Water absorption rate is>=30%; Pore volume is 0.35-0.85ml/g.

6. method according to claim 5, is characterized in that, the crushing strength of described catalyst carrier is 40-200N/ grain; Specific area is 0.5-2.0m ²/ g; Water absorption rate is>=45%; Pore volume is 0.40-0.8ml/g.

7. method according to claim 1 and 2, is characterized in that, described active A 1 ₂o ₃powder is selected from γ-A1 ₂o ₃and/or ρ-A1 ₂o ₃powder; Described active A 1 ₂o ₃powder content is based on component i) gross weight more than 10%;

According to the described porous A1 in catalyst carrier prepared by said method ₂o ₃in described α-A1 ₂o ₃weight content to be at least carrier gross weight be 90 ~ 99.9%; It is 0.1-3wt% that metallic element weight accounts for total weight of carrier content; Described alkaline earth metal compound is selected from one or more in the oxide of alkaline-earth metal, sulfate, acetate, nitrate, carbonate and oxalates.

8. method according to claim 7, is characterized in that, described active A 1 ₂o ₃powder content is based on component i) gross weight 100%;

Described alkaline earth metal compound is selected from one or more in barium monoxide, barium sulfate, barium nitrate and brium carbonate.

9. method according to claim 1 and 2, is characterized in that, described active A 1 ₂o ₃a1 in powder ₂o ₃content is higher than 99%.

10. method according to claim 9, is characterized in that, described active A 1 ₂o ₃a1 in powder ₂o ₃content is higher than 99.9%.

11. methods according to claim 1 and 2, is characterized in that, the gross weight based on component i and ii is the mineralizer of 1-4wt%.

12. methods according to claim 1 and 2, is characterized in that, the formed body described in step 2 is dry is 80-200 DEG C in temperature; The roasting at 1100-1600 DEG C of dried formed body.

13. methods according to claim 12, is characterized in that, the roasting at 1200-1500 DEG C of dried formed body.

14. methods according to claim 1 and 2, is characterized in that, the component i described in step one) with component ii) weight ratio be 0.1 ~ 16:1.

15. methods according to claim 14, is characterized in that, the component i described in step one) with component ii) weight ratio be 1 ~ 6:1.

16. methods according to claim 1 and 2, is characterized in that, the component iv described in step one) described mineralizer is fluoride.

17. methods according to claim 16, is characterized in that, described fluoride is selected from inorganic fluoride.

18. methods according to claim 17, is characterized in that, described fluoride is selected from one or more in hydrogen fluoride, ammonium fluoride, aluminum fluoride, magnesium fluoride and ice crystal.

19. methods according to claim 1 and 2, is characterized in that, the component v described in step one) comprise acid in bonding agent.

20. methods according to claim 19, is characterized in that, described acid is selected from one or more in nitric acid, formic acid, acetic acid, propionic acid and hydrochloric acid.

21. methods according to claim 20, is characterized in that, described acid is selected from nitric acid and/or acetic acid.

22. methods according to claim 19, is characterized in that, the consumption of described binding agent is based on component i), ii), iii) and gross weight 15-60% iv).

23. methods according to claim 22, is characterized in that, the consumption of described binding agent is based on component i), ii), iii) and the 15-50% of gross weight iv).

Silver catalyst prepared by 24. 1 kinds of carriers utilizing the method according to claim 1-5 any one to prepare, this catalyst comprises:

1) catalyst carrier;

2) deposition silver on this carrier;

3) alkali metal and/or alkaline-earth metal or the compound based on alkali metal and/or alkaline-earth metal;

4) rhenium metal and/or the compound based on rhenium; And

5) the collaborative auxiliary element of rhenium, it is selected from one or more metals in chromium, molybdenum, tungsten and boron, and/or is selected from the compound based on one or more elements in chromium, molybdenum, tungsten and boron.