Support for preparing silver catalyst and method for preparing the same, silver catalyst and method for preparing the same and application thereof

Abstract

The application belongs to the field of silver catalysts, and particularly relates to a carrier for preparing a silver catalyst, a preparation method of the carrier, the silver catalyst, a preparation method and application of the silver catalyst. The carrier comprises an alpha-Al2O3 carrier, hollow-configuration zirconium oxide and tungsten oxide loaded on the surface of the alpha-Al2O3 carrier; and the content of each component relative to the alpha-Al2O3 carrier is as follows: 0.02-4.00 wt% of the hollow-configuration zirconium oxide and 0.002-0.500 wt% of the tungsten oxide. The application makes the alpha-Al2O3 carrier rough by acid etching on the surface of the alpha-Al2O3 carrier, sequentially carries out ordered loading of the hollow-configuration zirconium oxide and the tungsten oxide, and then carries out high-temperature calcination and solidification, so that the silver catalyst prepared therefrom has high selectivity and reaction activity, and is particularly suitable for the reaction of ethylene oxidation for producing ethylene oxide.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of silver catalysts, and in particular, relates to a carrier for preparing a silver catalyst and a preparation method thereof, a silver catalyst and a preparation method and application thereof. BACKGROUND

[0002] Under the action of silver catalyst, ethylene oxidation mainly generates ethylene oxide, and at the same time, side reactions occur to generate carbon dioxide and water, wherein activity, selectivity and stability are the main performance indicators of the silver catalyst. The so-called activity refers to the reaction temperature required when the ethylene oxide production process reaches a certain reaction load. The lower the reaction temperature, the higher the activity of the catalyst. The so-called selectivity refers to the ratio of the number of moles of ethylene converted into ethylene oxide to the total reaction moles of ethylene. The so-called stability is expressed as the decline rate of activity and selectivity, and the smaller the decline rate, the better the stability of the catalyst. The use of a silver catalyst with high activity, high selectivity and good stability in the process of ethylene oxidation to produce ethylene oxide can greatly improve the economic benefit, and therefore, the manufacture of a silver catalyst with high activity, high selectivity and good stability is the main direction of silver catalyst research. The performance of the silver catalyst is not only related to the composition and preparation method of the catalyst, but also related to the performance and preparation method of the carrier used by the catalyst.

[0003] The preparation method of the silver catalyst in the prior art includes two processes of preparation of a porous carrier (such as alumina) and application of active components and adjuvants to the carrier. In the preparation process of the silver catalyst, for the carrier with α-Al2O3 as the main component, a suitable specific surface area and pore structure are required, which on the one hand provides sufficient space for the ethylene epoxidation reaction to diffuse the reaction heat, and on the other hand is also conducive to the timely desorption of the reaction product ethylene oxide to avoid deep oxidation to generate the byproduct carbon dioxide. German patent WO2021260138A1 provides a shaped catalyst body for the vapor-phase oxidation of ethylene to produce ethylene oxide, which has a BET surface area of 2-20 m 2 / g and contains silver and rhenium promoters deposited on a porous-alumina catalyst carrier, characterized in that the carrier has a calcination history of at least 1460°C, and the catalyst carrier has a high surface area and a small amount of ethylene oxide isomerization and / or decomposition activity. Chinese patent CN1009437B uses a suitable proportion of trihydrate alumina to prepare an alumina carrier with a specific surface area of 0.2-2 m 2 / g and a pore volume of more than 0.5 mL / g, wherein the pores with a pore radius of more than 30 μm account for 25% or less, which can achieve a selectivity of 83-84% for the ethylene epoxidation reaction.

[0004] It is also an important research direction to improve the performance of silver catalyst by adding other components to the alumina carrier. In addition, the performance of silver catalyst can also be improved by chemical treatment of the alumina carrier. German patent WO2021260185A1 provides a sheet-shaped catalyst carrier characterized by an alpha-alumina content of at least 85 wt.%, a pore volume of at least 0.40 mL / g measured by the mercury porosimetry method, a BET surface area of 0.5-5.0 m 2 / g, the sheet-shaped catalyst carrier is an alpha-alumina catalyst carrier which has a high geometric precision and shows a high total pore volume, thereby allowing impregnation with a large amount of silver, while showing a sufficiently large surface area to provide optimal dispersion of catalytically active substances, in particular metallic substances. European patent EP0150238B1 uses a small amount of barium aluminate or barium silicate binder in the manufacturing process of high-purity, low-surface alumina carrier, claiming to improve the crushing strength and wear resistance of the carrier, the specific surface area of the carrier manufactured by the patent is less than 0.3 m 2 / g, the activity and selectivity of the prepared catalysts are both low. US4740493A, US4829043A and EP0501317A1 use alumina carriers containing a certain amount of Ca, Al, K, Na soluble salts, which are claimed to reduce the rate of decline of the selectivity of the catalyst during use. US5384302A claims that the pretreatment of α-Al2O3 reduces the content of Na, K, Ca, Al ions in the carrier, thereby improving the crushing strength and wear resistance of the carrier. KR102258044B1 adjusts the metal crystal size by adding polyvinylpyrrolidone to prepare a catalyst for generating high-yield ethylene oxide from ethylene. EP0712334B1 loads an effective amount of silver, an auxiliary amount of alkali metal, an auxiliary amount of magnesium and an auxiliary amount of rhenium on a carrier containing at least 85% alumina and 0.001-2% magnesium in the form of an oxide to prepare a silver catalyst, thereby improving the stability of the catalyst. US5100859A, US5145824A, EP0900126B1, US5801259A, US5733842A add alkaline earth metal, silicon and zirconium to α-Al2O3 to prepare a carrier, and then impregnate silver, an auxiliary amount of alkali metal, an auxiliary amount of rhenium and its auxiliary agents to prepare a silver catalyst, and the patent points out that the alkaline earth metal is preferably calcium, strontium and barium salts used together with zirconium compounds, and it is unknown that the addition of both affects the performance of the catalyst. US5739075A pre-deposits an auxiliary amount of rare earth metal and another auxiliary amount of metal salt (alkaline earth metal or Group VIII transition metal) on the surface of the alumina carrier, and then performs a calcination treatment, and finally prepares a silver catalyst from the treated carrier, and the evaluation results show that the selectivity decline rate of the catalyst is less than that of the catalyst sample without pre-deposition treatment. CN1511632A finds that the addition of a heavy alkaline earth metal compound to the alumina raw material to prepare a carrier, impregnation of a silver compound, an organic amine and a specific auxiliary agent to prepare a solution, and heat treatment in an oxygen-containing mixed gas, the prepared silver catalyst has improved activity and selectivity in the ethylene oxidation reaction.

[0005] Although the above patent documents use various methods to improve the alumina carrier, the activity, stability and selectivity of the catalyst are improved to different degrees, but as the large-scale industrial application of the high-selectivity silver catalyst containing Re, the requirements for the performance of the catalyst are also increasing, and therefore, the performance of the silver catalyst needs to be continuously improved. SUMMARY

[0006] In view of the above prior art, the inventors of the present application have made extensive and in-depth research in the field of silver catalysts, and as a result, it has been found that, by performing acid etching on the surface of an α-Al2O3 carrier, and then loading hollow-structured zirconium oxide on the surface of the alumina by impregnating a zirconium salt and a template agent and drying, and then impregnating a tungstic acid and / or tungstate solution and drying, and then high-temperature calcination, and finally impregnating a silver ammonia solution and drying, the selectivity and reactivity of the silver catalyst prepared therefrom can be significantly improved.

[0007] The first aspect of the present application provides a carrier for preparing a silver catalyst, which comprises:

[0008] an α-Al2O3 carrier, hollow-structured zirconium oxide and tungsten oxide loaded on the surface of the α-Al2O3 carrier;

[0009] The content of each component is, relative to the α-Al2O3 carrier:

[0010] hollow-structured zirconium oxide 0.02-4.00 wt%, and tungsten oxide 0.002-0.500 wt%.

[0011] The second aspect of the present application provides a preparation method for preparing a carrier for preparing a silver catalyst, which comprises:

[0012] (1) impregnating α-A12O3 in a first solution, and then solid-liquid separation and drying;

[0013] (2) impregnating the carrier obtained in step (1) in a second solution, and then solid-liquid separation, drying and calcination to obtain the carrier for preparing a silver catalyst;

[0014] The first solution is a mixed solution of an acid, a zirconium salt and a template agent;

[0015] The second solution is a tungstic acid and / or tungstate solution, and the solvent of the tungstate solution is selected from at least one of water, ammonia water and amine compounds.

[0016] The third aspect of the present application provides a carrier prepared by the above preparation method.

[0017] The fourth aspect of the present application provides a silver catalyst, which comprises:

[0018] a carrier, silver, an alkali metal promoter, an optional rhenium promoter, and an optional co-promoter of the rhenium promoter loaded on the surface of the carrier;

[0019] The carrier is the above-mentioned carrier for preparing a silver catalyst, or is the carrier prepared by the above-mentioned method.

[0020] The fifth aspect of the present application provides a preparation method of the above-mentioned silver catalyst, which comprises:

[0021] The carrier is immersed in silver-ammonia solution, solid-liquid separation, drying, to obtain the silver catalyst.

[0022] The sixth aspect of the present application provides the application of the above-mentioned silver catalyst in the reaction of ethylene oxidation to produce ethylene oxide.

[0023] Compared with the prior art, the present application has the following advantages:

[0024] At the same time of acid etching on the surface of the α-Al2O3 carrier, hollow-structured zirconium oxide is loaded on the surface of the alumina by impregnating zirconium salt and template agent and drying, then impregnating tungstic acid and / or tungstate solution and drying, and finally high-temperature calcination, and impregnating silver-ammonia solution and drying, which can significantly improve the selectivity and reactivity of the silver catalyst made therefrom, and is particularly suitable for the reaction of ethylene oxidation to produce ethylene oxide.

[0025] Other features and advantages of the present application will be described in detail in the following specific embodiments. DETAILED DESCRIPTION

[0026] The specific embodiments of the present application are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0027] The first aspect of the present application provides a carrier for preparing a silver catalyst, which comprises:

[0028] α-Al2O3 carrier, hollow-structured zirconium oxide and tungsten oxide loaded on the surface of the α-Al2O3 carrier;

[0029] The content of each component is:

[0030] Hollow-structured zirconium oxide 0.02-4.00wt%, tungsten oxide 0.002-0.500wt%.

[0031] As a preferred solution, the content of each component is: hollow-structured zirconium oxide 0.05-1.00wt%, tungsten oxide 0.005-0.100wt%, relative to the α-Al2O3 carrier.

[0032] As a preferred solution, the α-Al2O3 carrier comprises at least one of the following features:

[0033] The content of α-A12O3 is ≥90%;

[0034] The crushing strength is 20-200N / particle;

[0035] The specific surface area is 0.2-3.0m 2 / g;

[0036] water absorption rate ≥ 30 %;

[0037] pore volume is 0.30-0.85 mL / g.

[0038] The second aspect of the present application provides a preparation method for preparing a carrier for silver catalyst, which comprises:

[0039] (1) impregnating α-A12O3 in a first solution, then solid-liquid separation and drying;

[0040] (2) impregnating the carrier obtained in step (1) in a second solution, then solid-liquid separation, drying and calcination to obtain the carrier for preparing silver catalyst;

[0041] The first solution is a mixed solution of acid, zirconium salt and template agent;

[0042] The second solution is a tungstic acid and / or tungstate solution, and the solvent of the tungstate solution is selected from at least one of water, ammonia and amine compounds.

[0043] In the present application, the surface of the carrier formed after acid etching the carrier is rough.

[0044] In the present application, the solid-liquid separation in step (1) and step (2) can be leaching, and the leaching process is preferably performed to reduce the excess impregnation liquid attached to the surface of the carrier as much as possible. The leaching process can remove the excess dust in the alumina carrier.

[0045] As a preferred solution, in step (1), the impregnation time is 10-300 minutes, and the impregnation is performed under a pressure of less than 100 mmHg.

[0046] As a preferred solution, in step (2), the impregnation time is 10-300 minutes, and the impregnation is performed under a pressure of less than 100 mmHg.

[0047] As a preferred solution, in step (1), the drying is performed in air or in a nitrogen-oxygen mixed gas with an oxygen content of not more than 21%; the drying temperature is 100-600°C, preferably 150-500°C; and the drying time is 0.5-120 minutes, preferably 1-30 minutes.

[0048] As a preferred solution, in step (2), the drying is performed in air or in a nitrogen-oxygen mixed gas with an oxygen content of not more than 21%; the drying temperature is 100-600°C, preferably 150-500°C; and the drying time is 0.5-120 minutes, preferably 1-30 minutes.

[0049] Preferably, in step (2), the calcination is carried out in air or in a mixture of nitrogen and oxygen having an oxygen content of not more than 21%; the calcination is carried out at a temperature of 500 to 1400°C, preferably 700 to 1200°C; and the calcination is carried out for a time of 5 to 240 minutes, preferably 10 to 120 minutes.

[0050] Preferably, the acid is selected from at least one of sulfuric acid, nitric acid and oxalic acid.

[0051] Preferably, the zirconium salt is selected from at least one of zirconium sulfate, zirconium nitrate and zirconyl nitrate.

[0052] Preferably, the template agent is selected from at least one of chitosan, polystyrene and glucosamine.

[0053] Preferably, the acid is present in an amount of 0.2 to 20.0 wt%, the zirconium salt is present in an amount of 0.05 to 10.00 wt%, and the template agent is present in an amount of 0.02 to 6.0 wt%, based on the total weight of the first solution.

[0054] Preferably, the acid is present in an amount of 1.0 to 15.0 wt%, the zirconium salt is present in an amount of 0.1 to 5.0 wt%, and the template agent is present in an amount of 0.05 to 3.0 wt%, based on the total weight of the first solution.

[0055] Preferably, the tungstate is ammonium tungstate and / or potassium tungstate.

[0056] Preferably, the tungstic acid and / or tungstate is present in an amount of 0.002 to 0.500 wt%, based on the total weight of the second solution.

[0057] Preferably, the tungstic acid and / or tungstate is present in an amount of 0.01 to 0.20 wt%, based on the total weight of the second solution.

[0058] A third aspect of the present application provides a support prepared by the above-mentioned method.

[0059] A fourth aspect of the present application provides a silver catalyst comprising:

[0060] a support, silver supported on the surface of the support, an alkali metal promoter, optionally a rhenium promoter, and optionally a co-promoter of the rhenium promoter;

[0061] The support is the support used in the above-mentioned method for preparing a silver catalyst, or is the support prepared by the above-mentioned method.

[0062] Preferably, the contents of the respective components are as follows, relative to the silver catalyst:

[0063] Silver 2-39 wt% in terms of atoms, alkali metal promoter 1-2000 ppm, rhenium promoter in terms of rhenium atoms 0-2000 ppm, co-promoter of rhenium in terms of atoms 0-2000 ppm.

[0064] As a further preferred aspect, the content of each component is, with respect to the silver catalyst:

[0065] Silver 10-35 wt% in terms of atoms, alkali metal promoter 5-2000 ppm, rhenium promoter in terms of rhenium atoms 100-1000 ppm, co-promoter of rhenium in terms of atoms 100-1000 ppm.

[0066] As a preferred aspect, the alkali metal promoter is selected from at least one of lithium, sodium, potassium, rubidium and cesium each of which is a compound. Preferably, the alkali metal promoter is added in an amount such that the content of the alkali metal promoter in the silver catalyst is 1-2000 ppm.

[0067] As a preferred aspect, the rhenium promoter is selected from at least one of oxides of rhenium, perrhenic acid, cesium perrhenate, methyltrioxorhenium (VII) and ammonium perrhenate.

[0068] As a preferred aspect, the co-promoter of the rhenium promoter is selected from at least one of salts or acids containing manganese, chromium, sulfur, cobalt, molybdenum, nickel.

[0069] A fifth aspect of the present application provides a method for preparing the above-mentioned silver catalyst, which comprises:

[0070] The carrier is immersed in a silver ammonia solution, solid-liquid separation, drying, to obtain the silver catalyst.

[0071] In the method for preparing the silver catalyst, the solid-liquid separation can be leaching, and the leaching process is preferably performed to reduce the excess immersion liquid attached to the surface of the carrier as much as possible. The leaching process can be performed at the same time to remove the excess dust in the alumina carrier.

[0072] In the method for preparing the silver catalyst, the immersion can be performed according to the conventional method in the art. The carrier is completely immersed in the silver ammonia solution, and the immersion is performed for 10-300 minutes. The temperature of the immersion liquid is preferably kept below 30°C to prevent the silver-containing compound from being decomposed and precipitated in advance. The immersion process can be accelerated by reducing the pressure to below 100 mmHg, and the surface of the carrier is preferably free of small bubbles and the inner and outer surfaces are fully wetted.

[0073] As a preferred aspect, the immersion is preferably performed for 10-300 minutes and under a pressure of 100 mmHg or less.

[0074] As a preferred solution, the drying is carried out in air or in a mixture of nitrogen and oxygen with an oxygen content of not more than 21%, at a temperature of 100-600°C, more preferably 150-500°C, for a time of 0.5-120 minutes, more preferably 1-30 minutes.

[0075] As a preferred solution, the silver ammine solution comprises a silver-containing compound, an amine compound, water, an alkali metal promoter, optionally a rhenium promoter, and optionally a co-promoter of the rhenium promoter; the content of the amine compound is 10-90 wt% based on the total weight of the silver ammine solution.

[0076] As a further preferred solution, the silver-containing compound is selected from at least one of silver acetate, silver nitrate and silver oxalate. Preferably, the silver-containing compound is added in an amount such that the content of silver in atomic terms in the silver catalyst is 2-39 wt%, preferably 10-35 wt%.

[0077] As a further preferred solution, the amine compound is selected from at least one of ammonia, ethylamine, n-propylamine, ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, N,N-dimethylformamide, ethanolamine and propanolamine.

[0078] The sixth aspect of the present application provides the use of the above-mentioned silver catalyst in the reaction of ethylene oxidation to produce ethylene oxide.

[0079] The silver catalyst prepared according to the present application has high selectivity and reactivity, and can be used in the reaction of ethylene oxidation to produce ethylene oxide. Specifically, in the presence of the silver catalyst, a mixture of ethylene and oxygen or other gases is reacted in a fixed-bed micro-tube reactor.

[0080] The present application will be further described in conjunction with the following examples, but the scope of the present application is not limited to these examples.

[0081] Determination of catalyst performance:

[0082] The various silver catalysts of the present application are evaluated for initial performance and stability using a laboratory reactor (hereinafter referred to as "micro-reactor") evaluation apparatus. The reactor used in the micro-reactor evaluation apparatus is a stainless steel tube with an inner diameter of 4 mm, and the reactor is placed in a heating jacket. The catalyst is packed in a volume of 1 mL, and inert packing is provided at the lower part to position the catalyst bed in the constant temperature zone of the heating jacket.

[0083] Determination of initial activity and selectivity:

[0084] The conditions for determining activity and selectivity used in the present application are as follows:

[0085] The composition of the reaction gas (mol%) is shown in Table 1.

[0086] Table 1

[0087] ethylene (C2H4) 28±1 oxygen (O2) 7.4±0.2 carbon dioxide (CO2) ＜3 Stabilizing gas (N2) Balance Inhibitor dichloroethane Optimized regulation Reaction pressure 2.1 MPa Space velocity Adjustable between 3000-7000 / h Concentration at reactor outlet EO 1.5-2.8 mol% Space-time yield 88-385 g EO / m L Cat. / h

[0088] The reactor inlet and outlet gas compositions were continuously measured after the above reaction conditions were reached. The measured results were corrected for volume shrinkage and calculated for selectivity according to the following equation:

[0089]

[0090] where ΔEO is the difference in ethylene oxide concentration between the outlet gas and the inlet gas, and the average of 10 or more test data was taken as the test result for the day.

[0091] The activity of the catalyst was measured by the level of the reaction temperature when a certain EO concentration was reached.

[0092] The elemental content in the present application was determined by chemical analysis and XRF. The micro-morphology of the catalyst and its carrier was characterized by SEM and TEM.

[0093] The α-alumina carrier used in Examples 1-9 and Comparative Example 1 was prepared from the same carrier formula, and the specific details can be found in CN88100400.6, CN1634652A and US5063195, which will not be described in detail herein. The α-alumina carrier has the following characteristics: α-A1203 content of 99.5%; crushing strength of 85 N / particle; specific surface area of 1.13 m 2 / g; water absorption of 45%; pore volume of 0.47 mL / g.

[0094] Example 1

[0095] First, 198 mL of a 5 wt% sulfuric acid aqueous solution was prepared in a glass beaker, then 2 g of zirconium sulfate and 0.5 g of chitosan were added to the sulfuric acid aqueous solution, and the mixture was stirred until uniform. 15 g of the α-alumina carrier was placed in a glass container capable of being evacuated, and the above impregnation solution was added to completely immerse the carrier. The vacuum was drawn to 10 mmHg or higher, and maintained for about 15 minutes, then the excess solution was removed by decanting, and the impregnated carrier sample was placed in an air stream at 400°C for about 3 minutes. 200 mL of a 10 wt% ammonia aqueous solution was prepared in a glass beaker, then 1.3 g of ammonium tungstate (H 26 N6O 40 W 12) and mix well. Place the zirconium sulfate and chitosan impregnated dilute sulfuric acid solution and heated support into a glass container that can be evacuated and add the ammonium tungstate aqueous impregnation solution to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Heat the impregnated support sample in a stream of air at 400°C for about 3 minutes and finally heat at 900°C for 1 hour to produce the support example 1.

[0096] The surface loading of the components of the support example 1 was 0.22 wt% zirconium oxide and 0.026 wt% tungsten oxide in a hollow configuration.

[0097] In a glass beaker with stirring, add 32.1 g ethylenediamine, 10.8 g ethanolamine and 179.8 g deionized water to make a mixture; slowly add 72.2 g silver oxalate to the mixture while maintaining the temperature below 40°C with continued stirring to dissolve the silver oxalate completely; then add 2.25 mL of a cesium nitrate aqueous solution (0.03995 g / mL concentration based on the atomic weight of cesium) and 2.78 mL of a high rhenium ammonium salt aqueous solution (0.0162 g / mL concentration based on the atomic weight of rhenium) in sequence to make 300 g of an impregnation solution.

[0098] Take 15 g of the support example 1 and place it into a glass container that can be evacuated and add the silver amine impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Finally, heat the impregnated support sample in a stream of air at 350°C for about 2 minutes to produce the silver catalyst example 1.

[0099] The loading of the components relative to the silver catalyst example 1 was 11.1 wt% silver on an atomic basis, 169 ppm cesium promoter on an atomic basis and 94 ppm rhenium promoter on an atomic basis.

[0100] Example 2

[0101] First, prepare a 10 wt% sulfuric acid aqueous solution 198 mL in a glass beaker, then add 2 g zirconium sulfate, 0.5 g chitosan to the sulfuric acid aqueous solution and mix well. Take 15 g of the α-alumina support and place it into a glass container that can be evacuated and add the impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Heat the impregnated support sample in a stream of air at 400°C for about 3 minutes. Prepare a 10 wt% aqueous ammonia solution 200 mL in a glass beaker, then add 1.3 g ammonium tungstate (H 26 N6O 40 W 12) and mix well. Place the zirconium sulfate and chitosan impregnated dilute sulfuric acid solution and heated support into a glass container that can be evacuated and add the ammonium tungstate aqueous impregnation solution to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Heat the impregnated support sample in a stream of air at 400°C for about 3 minutes and finally heat at 900°C for 1 hour to produce the support example 2.

[0102] The surface loading of the components of the support example 2 was 0.23 wt% zirconium oxide, 0.025 wt% tungsten oxide in a hollow configuration.

[0103] In a glass beaker with stirring, add 32.1 g ethylenediamine, 10.8 g ethanolamine and 179.8 g deionized water to obtain a mixture; slowly add 72.2 g silver oxalate to the mixture while maintaining the temperature below 40°C with continued stirring to completely dissolve the silver oxalate; then add 2.25 mL of a cesium nitrate aqueous solution (0.03995 g / mL concentration based on the atomic weight of cesium), 2.78 mL of a high rhenium ammonium salt aqueous solution (0.0162 g / mL concentration based on the atomic weight of rhenium) in sequence, mix well to produce 300 g of impregnation solution for use.

[0104] Take 15 g of the support example 2 and place it into a glass container that can be evacuated and add the silver amine impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Finally, heat the impregnated support sample in a stream of air at 350°C for about 2 minutes to produce the silver catalyst example 2.

[0105] The loading of the components relative to the silver catalyst example 2 was 11.2 wt% silver on an atomic basis, 172 ppm cesium promoter on an atomic basis, and 96 ppm rhenium promoter on an atomic basis.

[0106] Example 3

[0107] First, prepare a 5 wt% nitric acid aqueous solution 198 mL in a glass beaker, then add 2 g zirconium sulfate, 0.5 g chitosan to the nitric acid aqueous solution and mix well. Take 15 g of the α-alumina support and place it into a glass container that can be evacuated and add the impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Heat the impregnated support sample in a stream of air at 400°C for about 3 minutes. Prepare a 10 wt% aqueous ammonia solution 200 mL in a glass beaker, then add 1.3 g ammonium tungstate (H 26 N6O 40 W 12) and mix well. Place the zirconium sulfate impregnated and dilute nitric acid solution of chitosan and heated support into a glass container that can be evacuated and add the ammonium tungstate aqueous impregnation solution to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Place the impregnated support sample into an air stream at 400°C for about 3 minutes and finally heat at 900°C for 1 hour to produce the support example 3.

[0108] The surface loading of the components of the support example 3 was 0.21 wt% zirconium oxide, 0.027 wt% tungsten oxide in a hollow configuration.

[0109] In a glass beaker with stirring, add 32.1 g ethylenediamine, 10.8 g ethanolamine and 179.8 g deionized water to obtain a mixture; slowly add 72.2 g silver oxalate to the mixture while maintaining the temperature below 40°C with continued stirring to completely dissolve the silver oxalate; then add 2.25 mL of a cesium nitrate aqueous solution (0.03995 g / mL concentration based on the atomic weight of cesium), 2.78 mL of a high rhenium ammonium salt aqueous solution (0.0162 g / mL concentration based on the atomic weight of rhenium) in sequence, and mix well to produce 300 g of an impregnation solution for use.

[0110] Take 15 g of the support example 3 and place it into a glass container that can be evacuated and add the silver amine impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Finally, place the impregnated support sample into an air stream at 350°C for about 2 minutes to produce the silver catalyst example 3.

[0111] The loading of the components relative to the silver catalyst example 3 was 11.1 wt% silver on an atomic basis, 171 ppm cesium promoter on an atomic basis, and 93 ppm rhenium promoter on an atomic basis.

[0112] Example 4

[0113] First, prepare a 5 wt% sulfuric acid aqueous solution 198 mL in a glass beaker, then add 4 g zirconium sulfate, 0.5 g chitosan to the sulfuric acid aqueous solution and mix well. Take 15 g of the α-alumina support and place it into a glass container that can be evacuated and add the impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Place the impregnated support sample into an air stream at 400°C for about 3 minutes. Prepare a 10 wt% aqueous ammonia solution 200 mL in a glass beaker, then add 1.3 g ammonium tungstate (H 26 N6O 40 W 12) and mix well. Place the zirconium sulfate impregnated and dilute sulfuric acid solution of chitosan and heated support into a glass container that can be evacuated and add the ammonium tungstate aqueous impregnation solution to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Place the impregnated support sample into an air stream at 400°C for about 3 minutes and finally heat at 900°C for 1 hour to produce the support example 4.

[0114] The surface loading of the components of the support example 4 was 0.43 wt% zirconium oxide in a hollow configuration and 0.026 wt% tungsten oxide.

[0115] Into a glass beaker with stirring, add 32.1 g ethylenediamine, 10.8 g ethanolamine and 179.8 g deionized water to make a mixture; slowly add 72.2 g silver oxalate to the mixture while maintaining the temperature below 40°C with continued stirring to completely dissolve the silver oxalate; then add 2.25 mL of a cesium nitrate aqueous solution (0.03995 g / mL concentration based on the atomic weight of cesium) and 2.78 mL of a high rhenium ammonium salt aqueous solution (0.0162 g / mL concentration based on the atomic weight of rhenium) in sequence to make 300 g of an impregnation solution.

[0116] Take 15 g of the support example 4 and place it into a glass container that can be evacuated and add the silver amine impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Finally, place the impregnated support sample into an air stream at 350°C for about 2 minutes to produce the silver catalyst example 4.

[0117] The loading of the components relative to the silver catalyst example 4 was 11.3 wt% silver on an atomic basis, 167 ppm cesium promoter on an atomic basis and 92 ppm rhenium promoter on an atomic basis.

[0118] Example 5

[0119] First, prepare a 5 wt% sulfuric acid aqueous solution 198 mL in a glass beaker, then add 2 g zirconium nitrate pentahydrate, 0.5 g chitosan to the sulfuric acid aqueous solution and mix well. Take 15 g of the α-alumina support and place it into a glass container that can be evacuated and add the impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Place the impregnated support sample into an air stream at 400°C for about 3 minutes. Prepare a 10 wt% aqueous ammonia solution 200 mL in a glass beaker, then add 1.3 g ammonium tungstate (H 26 N6O 40 W 12) and mix well. Place the zirconium sulfate impregnated and dilute sulfuric acid solution of chitosan and heated support into a glass container that can be evacuated and add the ammonium tungstate aqueous impregnation solution to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Place the impregnated support sample into an air stream at 400°C for about 3 minutes and finally heat at 900°C for 1 hour to produce the support example 5.

[0120] The surface loading of the components of the support example 5 was 0.14 wt% zirconium oxide, 0.025 wt% tungsten oxide in a hollow configuration.

[0121] In a glass beaker with stirring, add 32.1 g ethylenediamine, 10.8 g ethanolamine and 179.8 g deionized water to obtain a mixture; slowly add 72.2 g silver oxalate to the mixture while maintaining the temperature below 40°C with continued stirring to completely dissolve the silver oxalate; then add 2.25 mL of a cesium nitrate aqueous solution (0.03995 g / mL concentration based on the atomic weight of cesium), 2.78 mL of a high rhenium ammonium salt aqueous solution (0.0162 g / mL concentration based on the atomic weight of rhenium) in sequence, mix well to produce 300 g of impregnation solution for use.

[0122] Take 15 g of the support example 5 and place it into a glass container that can be evacuated and add the silver amine impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Finally, place the impregnated support sample into an air stream at 350°C for about 2 minutes to produce the silver catalyst example 5.

[0123] The loading of the components relative to the silver catalyst example 5 was 11.2 wt% silver on an atomic basis, 173 ppm cesium promoter on an atomic basis, and 95 ppm rhenium promoter on an atomic basis.

[0124] Example 6

[0125] First, prepare a 5 wt% sulfuric acid aqueous solution of 198 mL in a glass beaker, then add 2 g zirconium sulfate, 1 g chitosan to the sulfuric acid aqueous solution and mix well. Take 15 g of the α-alumina support and place it into a glass container that can be evacuated and add the impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Place the impregnated support sample into an air stream at 400°C for about 3 minutes. Prepare a 10 wt% aqueous ammonia solution of 200 mL in a glass beaker, then add 1.3 g ammonium tungstate (H 26 N6O 40 W 12) and mix well. Place the zirconium sulfate impregnated, dilute sulfuric acid solution of chitosan and heated support into a glass container that can be evacuated and add the ammonium tungstate aqueous impregnation solution to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain off the excess solution. Place the impregnated support sample into an air stream at 400°C for about 3 minutes and finally heat at 900°C for 1 hour to produce the support example 6.

[0126] The surface loading of the components of the support example 6 was 0.22 wt% zirconium oxide, 0.027 wt% tungsten oxide in a hollow configuration.

[0127] Into a glass beaker with stirring, add 32.1 g ethylenediamine, 10.8 g ethanolamine and 179.8 g deionized water to make a mixture; slowly add 72.2 g silver oxalate to the mixture while maintaining the temperature below 40°C with continued stirring to completely dissolve the silver oxalate; then add 2.25 mL of a cesium nitrate aqueous solution (0.03995 g / mL concentration based on the atomic weight of cesium), 2.78 mL of a high rhenium ammonium salt aqueous solution (0.0162 g / mL concentration based on the atomic weight of rhenium) in sequence, and mix well to make 300 g of an impregnation solution for use.

[0128] Take 15 g of the support example 6 and place it into a glass container that can be evacuated and add the silver amine impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain off the excess solution. Finally, place the impregnated support sample into an air stream at 350°C for about 2 minutes to produce the silver catalyst example 6.

[0129] The loading of the components relative to the silver catalyst example 6 was 11.0 wt% silver on an atomic basis, 171 ppm cesium promoter on an atomic basis, and 92 ppm rhenium promoter on an atomic basis.

[0130] Example 7

[0131] First, prepare a 5 wt% sulfuric acid aqueous solution 198 mL in a glass beaker, then add 2 g zirconium sulfate, 0.5 g polystyrene microspheres to the sulfuric acid aqueous solution and mix well. Take 15 g of the α-alumina support and place it into a glass container that can be evacuated and add the impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain off the excess solution. Place the impregnated support sample into an air stream at 400°C for about 3 minutes. Prepare a 10 wt% aqueous ammonia solution 200 mL in a glass beaker, then add 1.3 g ammonium tungstate (H 26 N6O 40 W 12) and mix well. Place the zirconium sulfate impregnated and dilute sulfuric acid solution of chitosan and heated support into a glass container that can be evacuated and add the ammonium tungstate aqueous impregnation solution to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Place the impregnated support sample into an air stream at 400°C for about 3 minutes and finally heat at 900°C for 1 hour to produce the support example 7.

[0132] The surface loading of the components of the support example 7 was 0.23 wt% zirconium oxide, 0.026 wt% tungsten oxide in a hollow configuration.

[0133] In a glass beaker with stirring, add 32.1 g ethylenediamine, 10.8 g ethanolamine and 179.8 g deionized water to make a mixture; slowly add 72.2 g silver oxalate to the mixture while maintaining the temperature below 40°C with continued stirring to completely dissolve the silver oxalate; then add 2.25 mL of a cesium nitrate aqueous solution (0.03995 g / mL concentration based on the atomic weight of cesium), 2.78 mL of a high rhenium ammonium salt aqueous solution (0.0162 g / mL concentration based on the atomic weight of rhenium) in sequence, mix well to make 300 g of an impregnation solution for use.

[0134] Take 15 g of the support example 7 and place it into a glass container that can be evacuated and add the silver amine impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Finally, place the impregnated support sample into an air stream at 350°C for about 2 minutes to produce the silver catalyst example 7.

[0135] The loading of the components relative to the silver catalyst example 7 was 11.3 wt% silver on an atomic basis, 174 ppm cesium promoter on an atomic basis, and 96 ppm rhenium promoter on an atomic basis.

[0136] Example 8

[0137] First, prepare a 5 wt% sulfuric acid aqueous solution 198 mL in a glass beaker, then add 2 g zirconium sulfate, 0.5 g chitosan to the sulfuric acid aqueous solution and mix well. Take 15 g of the α-alumina support and place it into a glass container that can be evacuated and add the impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Place the impregnated support sample into an air stream at 400°C for about 3 minutes. Prepare a 10 wt% aqueous ammonia solution 200 mL in a glass beaker, then add 2.6 g ammonium tungstate (H 26 N6O 40 W 12) and mix well. Place the zirconium sulfate impregnated, dilute sulfuric acid solution of chitosan and heat treated support into a glass container that can be evacuated and add the ammonium tungstate aqueous impregnation solution to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Finally, place the impregnated support sample into an air stream at 400°C for about 3 minutes and then heat at 900°C for 1 hour to produce the support of Example 8.

[0138] The surface loading of the components of the support of Example 8 was 0.21 wt% zirconium oxide in a hollow configuration and 0.052 wt% tungsten oxide.

[0139] Into a glass beaker with stirring, add 32.1 g ethylenediamine, 10.8 g ethanolamine and 179.8 g deionized water to produce a mixture; slowly add 72.2 g silver oxalate to the mixture while maintaining the temperature below 40°C with continued stirring until the silver oxalate is completely dissolved; then add 2.25 mL of an aqueous cesium nitrate solution (0.03995 g / mL cesium atomic weight) and 2.78 mL of an aqueous high rhenium ammonium salt solution (0.0162 g / mL rhenium atomic weight) in sequence and mix well to produce 300 g of an impregnation solution for use.

[0140] Take 15 g of the support of Example 8 and place it into a glass container that can be evacuated and add the silver amine impregnation solution above to completely immerse the support. Evacuate to above 10 mm Hg and hold for about 15 minutes, then drain the excess solution. Finally, place the impregnated support sample into an air stream at 350°C for about 2 minutes to produce the silver catalyst of Example 8.

[0141] The loading of the components of the silver catalyst of Example 8 was 11.2 wt% silver on an atomic basis, 173 ppm cesium on an atomic basis as an alkali metal promoter and 91 ppm rhenium on an atomic basis as a promoter.

[0142] Example 9

[0143] First, prepare 198 mL of a 5 wt% aqueous sulfuric acid solution in a glass beaker, then add 2 g of zirconium sulfate, 0.5 g of chitosan to the aqueous sulfuric acid solution and mix well. Take 15 g of the α-alumina support and place it in a glass container that can be evacuated, and add the impregnation solution above until the support is completely immersed. Evacuate to 10 mm Hg or more and maintain for about 15 minutes, then remove the excess solution by decanting. Place the impregnated support sample in an air stream at 400°C for about 3 minutes. Prepare 200 mL of a 10 wt% aqueous ammonia solution in a glass beaker, then add 1.3 g of tungstic acid to the aqueous ammonia solution and mix well. Place the support impregnated with the zirconium sulfate and chitosan in dilute sulfuric acid and heated in a glass container that can be evacuated, and add the ammonium tungstate aqueous ammonia impregnation solution until the support is completely immersed. Evacuate to 10 mm Hg or more and maintain for about 15 minutes, then remove the excess solution by decanting. Place the impregnated support sample in an air stream at 400°C for about 3 minutes, and finally heat at 900°C for 1 hour to produce the support of Example 9.

[0144] The content of each component on the surface of the support of Example 9 was 0.23 wt% of zirconium oxide in a hollow configuration, and 0.026 wt% of tungsten oxide.

[0145] In a glass beaker with stirring, add 32.1 g of ethylenediamine, 10.8 g of ethanolamine, and 179.8 g of deionized water to obtain a mixture; slowly add 72.2 g of silver oxalate to the mixture while maintaining the temperature below 40°C and continuously stirring to completely dissolve the silver oxalate; then sequentially add 2.25 mL of a cesium nitrate aqueous solution (concentration of 0.03995 g / mL based on the atomic weight of cesium), 2.78 mL of a high-rhenium ammonium rhenate aqueous solution (concentration of 0.0162 g / mL based on the atomic weight of rhenium), and mix well to obtain 300 g of an impregnation solution for use.

[0146] Take 15 g of the support of Example 9 and place it in a glass container that can be evacuated, and add the silver amine impregnation solution above until the support is completely immersed. Evacuate to 10 mm Hg or more and maintain for about 15 minutes, then remove the excess solution by decanting. Finally, place the impregnated support sample in an air stream at 350°C for about 2 minutes to produce the silver catalyst of Example 9.

[0147] The content of each component relative to the silver catalyst of Example 9 was 11.0 wt% of silver on an atomic basis, 172 ppm of the alkali metal cesium promoter, and 94 ppm of the rhenium promoter on an atomic basis of rhenium.

[0148] Comparative Example 1

[0149] In a glass beaker with stirring, add 32.1 g of ethylenediamine, 10.8 g of ethanolamine and 179.8 g of deionized water to obtain a mixture; slowly add 72.2 g of silver oxalate to the mixture, keep the temperature below 40°C and continue stirring until the silver oxalate is completely dissolved; then add 2.25 mL of cesium nitrate aqueous solution (concentration of 0.03995 g / mL, based on the atomic weight of cesium), 2.78 mL of high-rhenium ammonium solution (concentration of 0.0162 g / mL, based on the atomic weight of rhenium) in sequence, mix well to prepare 300 g of impregnation solution for use.

[0150] Take 15 g of the α-alumina carrier and place it in a glass container that can be evacuated, and add the above silver amine impregnation solution to completely immerse the carrier. Evacuate to above 10 mmHg, keep for about 15 minutes, then remove the excess solution by decanting. Finally, place the impregnated carrier sample in an air stream at 350°C for about 2 minutes to obtain the silver catalyst comparative example 1.

[0151] The content of each component relative to the silver catalyst comparative example 1 is: 11.1 wt% of silver in terms of atoms, 170 ppm of cesium alkali metal promoter, 93 ppm of rhenium promoter in terms of rhenium atoms.

[0152] Comparative Example 2

[0153] The difference from example 8 is that no tungsten compound is added, and 2.4 g of zirconium sulfate is added. The content of each component on the surface of the carrier comparative example 2 is: 0.26 wt% of zirconium oxide in a hollow configuration.

[0154] In a glass beaker with stirring, add 32.1 g of ethylenediamine, 10.8 g of ethanolamine and 179.8 g of deionized water to obtain a mixture; slowly add 72.2 g of silver oxalate to the mixture, keep the temperature below 40°C and continue stirring until the silver oxalate is completely dissolved; then add 2.25 mL of cesium nitrate aqueous solution (concentration of 0.03995 g / mL, based on the atomic weight of cesium), 2.78 mL of high-rhenium ammonium solution (concentration of 0.0162 g / mL, based on the atomic weight of rhenium) in sequence, mix well to prepare 300 g of impregnation solution for use.

[0155] Take 15 g of the carrier comparative example 2 and place it in a glass container that can be evacuated, and add the above silver amine impregnation solution to completely immerse the carrier. Evacuate to above 10 mmHg, keep for about 15 minutes, then remove the excess solution by decanting. Finally, place the impregnated carrier sample in an air stream at 350°C for about 2 minutes to obtain the silver catalyst comparative example 2.

[0156] The content of each component relative to the silver catalyst comparative example 2 is: 11.2 wt% of silver in terms of atoms, 168 ppm of cesium alkali metal promoter, 96 ppm of rhenium promoter in terms of rhenium atoms.

[0157] Comparative Example 3

[0158] The difference from Example 8 is that no zirconium compound is added and 13.7 g of ammonium tungstate is added.

[0159] The content of each component on the surface of the support of Comparative Example 3 is: tungsten oxide 0.26 wt%.

[0160] In a glass beaker with stirring, 32.1 g of ethylenediamine, 10.8 g of ethanolamine and 179.8 g of deionized water are added to obtain a mixture; 72.2 g of silver oxalate is slowly added to the mixture, and the temperature is kept below 40°C under continuous stirring to make the silver oxalate completely dissolved; then 2.25 mL of aqueous cesium nitrate solution (concentration of 0.03995 g / mL, based on the atomic weight of cesium), 2.78 mL of aqueous high-rhenium ammonium solution (concentration of 0.0162 g / mL, based on the atomic weight of rhenium) are added in sequence, and the mixture is uniformly mixed to obtain 300 g of impregnation solution for use.

[0161] Take 15 g of Comparative Example 3 support, put it into a glass container that can be vacuumed, and add the above silver amine impregnation solution to completely immerse the support. Vacuum to 10 mmHg or above, keep for about 15 minutes, then remove the excess solution by draining. Finally, the impregnated support sample is placed in an air stream at 350°C and heated for about 2 minutes to obtain silver catalyst Comparative Example 3.

[0162] The content of each component relative to silver catalyst Comparative Example 3 is: silver 11.3 wt% in atomic terms, cesium alkali metal promoter 174 ppm, rhenium promoter 91 ppm in terms of rhenium atoms.

[0163] The performance of the silver catalyst samples in the examples and comparative examples was determined under the aforementioned process conditions using a micro-reactor evaluation device, and the evaluation results are shown in Table 2.

[0164] Table 2 Evaluation results of silver catalysts Comparative Examples 1-3 and Examples 1-9

[0165]

[0166]

[0167] As can be seen from Table 1, the selectivity and reaction activity of the silver catalyst samples prepared using the surface composite modification technology of α-alumina support are significantly improved.

[0168] Embodiments of the application have been described above, as well as examples. None of the above description is exhaustive or complete with respect to the practice of the disclosed embodiments. Many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the before disclosure.

[0169] The endpoints of the ranges and any values described herein are not limited to the precise values recited as exactly that endpoint. Any values that are approximately a described value within tolerances acceptable by methods in the art and technologies disclosed herein are encompassed in this description. For a numeric range, the endpoints of each of the ranges are combined with themselves and with the individual points to form new numeric ranges that are specifically disclosed herein.

Claims

1. A support for the preparation of a silver catalyst, characterized in that, The carrier comprises: an α-Al2O3 carrier, hollow-structured zirconia and tungsten oxide supported on the surface of the α-Al2O3 carrier; the content of each component relative to the α-Al2O3 carrier is: hollow-structured zirconia 0.02-4.00 wt%, and tungsten oxide 0.002-0.500 wt%.

2. The carrier for preparing a silver catalyst according to claim 1, wherein, the content of each component relative to the α-Al2O3 carrier is: hollow-structured zirconia 0.05-1.00 wt%, and tungsten oxide 0.005-0.100 wt%.

3. The support for the preparation of a silver catalyst according to claim 1 or 2, wherein, The α-Al2O3 carrier comprises at least one of the following features: the α-Al2O3 content is ≥ 90%; the crushing strength is 20-200 N / particle; a specific surface area of 0.2 to 3.0 m 2 / g; the water absorption is ≥ 30%; the pore volume is 0.30-0.85 mL / g.

4. A production method for a carrier for a silver catalyst, characterized by, The preparation method comprises: (1) immersing α-Al2O3 in a first solution, then performing solid-liquid separation and drying; (2) immersing the carrier obtained in step (1) in a second solution, then performing solid-liquid separation, drying, and calcination to obtain the carrier for preparing a silver catalyst; the first solution is a mixed solution of an acid, a zirconium salt, and a template agent; the second solution is a tungstic acid and / or tungstate solution, and the solvent of the tungstate solution is selected from at least one of water, ammonia, and an amine compound.

5. The preparation method according to claim 4, wherein, in step (1), the immersion time is 10-300 minutes, and the immersion is performed under a pressure of less than 100 mmHg; in step (2), the immersion time is 10-300 minutes, and the immersion is performed under a pressure of less than 100 mmHg; in step (1), the drying is performed in air or in a nitrogen-oxygen mixed gas with an oxygen content of not more than 21%, the drying temperature is 100-600°C, and the drying time is 0.5-120 minutes; in step (2), the drying is performed in air or in a nitrogen-oxygen mixed gas with an oxygen content of not more than 21%, the drying temperature is 100-600°C, and the drying time is 0.5-120 minutes; in step (2), the calcination is performed in air or in a nitrogen-oxygen mixed gas with an oxygen content of not more than 21%, the calcination temperature is 500-1400°C, and the calcination time is 5-240 minutes.

6. The production method according to claim 5, wherein in step (1), the drying temperature is 150-500°C, and the drying time is 1-30 minutes; in step (2), the drying temperature is 150-500°C, and the drying time is 1-30 minutes; in step (2), the calcination temperature is 700-1200°C, and the calcination time is 10-120 minutes.

7. The preparation method according to claim 4, wherein, the acid is selected from at least one of sulfuric acid, nitric acid, and oxalic acid; the zirconium salt is selected from at least one of zirconium sulfate, zirconium nitrate, and oxozirconium nitrate; the template agent is selected from at least one of chitosan, polystyrene, and glucosamine; the tungstate is ammonium tungstate and / or potassium tungstate.

8. The production method according to claim 7, wherein The content of the acid is 0.2-20.0wt%, the content of the zirconium salt is 0.05-10.00wt%, and the content of the template agent is 0.02-6.0wt% based on the total weight of the first solution.

9. The production method according to claim 7, wherein The content of the acid is 1.0-15.0wt%, the content of the zirconium salt is 0.1-5.0wt%, and the content of the template agent is 0.05-3.0wt% based on the total weight of the first solution.

10. The production method according to claim 7, wherein The content of the tungstic acid and / or tungstate is 0.002-0.500wt% based on the total weight of the second solution.

11. The method of making according to claim 7, wherein, The content of the tungstic acid and / or tungstate is 0.01-0.20wt% based on the total weight of the second solution.

12. The carrier prepared by the preparation method of any one of claims 4-11.

13. A silver catalyst characterized in that, The silver catalyst comprises: a carrier, silver supported on the surface of the carrier, an alkali metal promoter, an optional rhenium promoter, and an optional co-promoter of the rhenium promoter; The carrier is the carrier for preparing the silver catalyst according to claim 1 or 2 or 3, or the carrier according to claim 12.

14. The silver catalyst according to claim 13, wherein, The content of each component is: silver 2-39wt% in terms of atoms, alkali metal promoter 1-2000ppm, rhenium promoter 0-2000ppm in terms of rhenium atoms, and co-promoter of the rhenium promoter 0-2000ppm in terms of atoms.

15. The silver catalyst of claim 14, wherein, The content of each component is: silver 10-35wt% in terms of atoms, alkali metal promoter 5-2000ppm, rhenium promoter 100-1000ppm in terms of rhenium atoms, and co-promoter of the rhenium promoter 100-1000ppm in terms of atoms.

16. The silver catalyst according to claim 13, wherein, The alkali metal promoter is selected from at least one of compounds of lithium, sodium, potassium, rubidium and cesium respectively; The rhenium promoter is selected from at least one of oxides of rhenium, perrhenic acid, cesium perrhenate, methyltrioxorhenium (VII) and ammonium perrhenate; The co-promoter of the rhenium promoter is selected from at least one of salts or acids containing manganese, chromium, sulfur, cobalt, molybdenum and nickel.

17. Process for the preparation of a silver catalyst according to any one of claims 13 to 16, characterized in that, The preparation method comprises: immersing the carrier in a silver ammonia solution, solid-liquid separation and drying to obtain the silver catalyst.

18. The method of making a silver catalyst according to claim 17, wherein, The immersion time is 10-300 minutes, and the immersion is carried out under a pressure of 100mmHg or less.

19. The method of making a silver catalyst according to claim 17, wherein, The drying is carried out in air or in a nitrogen-oxygen mixed gas with an oxygen content of not more than 21%, and the drying temperature is 100-600℃; the drying time is 0.5-120 minutes.

20. The method of making a silver catalyst according to claim 19, wherein, The drying temperature is 150-500℃; the drying time is 1-30 minutes.

21. The preparation method of the silver catalyst according to claim 17, wherein, The silver ammonia solution comprises a silver-containing compound, an amine compound, water, an alkali metal promoter, an optional rhenium promoter, and an optional co-promoter of the rhenium promoter; The content of the amine compound is 10-90wt% based on the total weight of the silver ammonia solution.

22. The method of making a silver catalyst according to claim 21, wherein, The silver-containing compound is selected from at least one of silver acetate, silver nitrate and silver oxalate; The amine compound is selected from at least one of ethylamine, n-propylamine, ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, N,N-dimethylformamide, ethanolamine, and propanolamine.

23. Use of the silver catalyst according to any one of claims 13 to 16 in the reaction of ethylene oxidation to produce ethylene oxide.

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