A catalyst carrier for producing ethylene oxide and a method for preparing the same

Abstract

The application discloses a catalyst carrier for producing ethylene oxide and a preparation method thereof, and belongs to the technical field of catalysts. The catalyst carrier for producing ethylene oxide has a specific surface area of 2.19-2.47 m 2 / g, a strength of 167-183 N, a water absorption of 56.4-58.5%, a peak value of a large pore diameter of 13.6-15.6 mu m, a ratio of 1-3 mu m pores to small pores of 96.8-99.3%, an EO space-time yield of a silver-loaded catalyst of 352-371 kgEO / (m 3 ·h), an EO selectivity of 91.2-93.4%, and an activity attenuation rate of 0.7-1.4%.

Description

Technical Field

[0001] This invention relates to a catalyst support for the production of ethylene oxide and its preparation method, belonging to the field of catalyst technology. Background Technology

[0002] Ethylene oxide (EO) is one of the main products of the ethylene industry, with wide applications. Its downstream product, ethylene glycol, also has high added value and various promising applications. The direct oxidation of ethylene to ethylene oxide using a silver catalyst is currently the main industrial synthetic route. This catalyst uses α-Al₂O₃ as a support, loading the active metal Ag to catalyze the production of ethylene oxide. The support, as a key component of the supported catalyst, plays a crucial role in the catalyst's performance. The oxidation of ethylene to ethylene oxide exhibits significant characteristics, placing specific requirements on the catalyst support's crystal phase, morphology, specific surface area, pore structure, acid-base properties, bulk density, water absorption, thermal conductivity, and mechanical strength. These requirements primarily include: 1) providing a suitable specific surface area, reasonable pore structure, pore size distribution, and a favorable dispersion environment for the supported noble metal Ag; 2) minimizing acid-base sites, ensuring only weak adsorption of ethylene or oxygen to prevent various side reactions; 3) good water absorption capacity to facilitate subsequent impregnation with high-load metals; 4) good thermal conductivity and heat dissipation to ensure rapid removal of heat released during the reaction, preventing localized hot spots that could lead to the growth of supported metal particles and deep oxidation side reactions; and 5) providing sufficient mechanical strength for the catalyst.

[0003] Currently, industrial silver catalyst supports generally employ macroporous structures (0.3~10 μm) and low specific surface areas (0.5~3 m²). 2 ·g -1Compared with common supports such as γ-alumina and silica, α-Al2O3 has a low hydroxyl density and few acidic sites on its surface, resulting in low catalytic activity for side reactions such as EO isomerization and deep oxidation, which can effectively improve the selectivity of the target product EO. While macroporous α-Al₂O₃ possesses the aforementioned significant advantages, it also has obvious drawbacks: First, the macroporous structure results in a smaller specific surface area and lower water absorption. When impregnated with silver ions, the loading capacity is relatively limited, ultimately leading to lower catalytic efficiency. In industrial applications, the catalyst loading is larger, which in turn increases the cost. Second, macroporous supports generally have lower mechanical strength, making them prone to pulverization and failure during use, severely impacting their lifespan. Third, during the preparation of macroporous α-Al₂O₃, the large amount of pore-forming agent added makes it difficult to precisely control the decomposition rate of the pore-forming agent during high-temperature calcination, easily resulting in defective pores. Finally, the preparation of macroporous α-Al₂O₃ often uses raw materials with larger particle sizes, making sintering between raw material particles difficult and requiring higher sintering temperatures. This leads to significant energy consumption issues, and excessively high sintering temperatures exacerbate the problem of abnormal alumina grain growth, which in turn significantly reduces the water absorption of α-Al₂O₃. Therefore, the silver-supported α-Al2O3 catalyst support used in the production of ethylene oxide still needs to optimize its internal pore structure and pore size, increase water absorption to increase silver loading, improve mechanical strength, and reduce sintering temperature to avoid abnormal grain growth.

[0004] Chinese patent CN116726919A discloses a modified support and preparation method for a catalyst used in the ethylene oxidation to ethylene oxide synthesis. The method involves directly modifying α-Al₂O₃ powder of a specific particle size to synthesize the catalyst support. The synthesized support exhibits uniform particle size and a reasonable pore structure, resulting in better activity and selectivity when used to prepare silver catalysts for ethylene oxide synthesis. However, the modified support for the ethylene oxidation to ethylene oxide catalyst obtained by this patent has a relatively low water absorption rate, mostly below 50% in most examples, and poor selectivity for ethylene oxide, with a maximum of only 91.3%.

[0005] Chinese patent CN107398303A discloses a catalyst support for the production of ethylene oxide, its preparation method, and its application. The support consists of an inner alumina matrix and an outer modified material surface. This support is obtained by the method described in this invention, which involves stirring, soaking, and then calcining an alumina support precursor containing a transition phase in a slurry containing attapulgite. The catalyst support obtained by this patent for the production of ethylene oxide has a water absorption rate of less than 50% and an EO selectivity of less than 90%, indicating relatively poor catalytic performance.

[0006] As can be seen above, the catalyst support used for the production of ethylene oxide, namely the silver-loaded α-Al2O3 catalyst support, still has significant problems such as unsatisfactory pore structure and distribution, low water absorption, small silver loading, insufficient mechanical strength, and poor catalytic activity after silver loading. Therefore, there is an urgent need to develop a silver-loaded α-Al2O3 catalyst support with better performance. Summary of the Invention

[0007] To address the shortcomings of the existing technology, this invention provides a catalyst support for the production of ethylene oxide and its preparation method, achieving the following objectives: to prepare an α-Al2O3 catalyst support with good pore size distribution, high water absorption, high silver loading, high mechanical strength, and good EO selectivity.

[0008] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0009] A catalyst support for the production of ethylene oxide and its preparation method are disclosed. The preparation method of the catalyst support for the production of ethylene oxide includes four steps: preparing a slurry, molding, drying and calcining, and impregnation modification.

[0010] The following are further improvements to the above technical solution:

[0011] Step 1: Prepare slurry

[0012] The composite foaming agent and deionized water are added to a double planetary mixer. After initial stirring and uniform dispersion, α-Al2O3 powder, pseudoboehmite, zirconate powder, composite mineralizer, and sintering aid are added. After stirring and uniform dispersion, zirconium-cerium ion complex liquid is added. After stirring and uniform dispersion again, a slurry is obtained.

[0013] The particle size of the α-Al2O3 powder is 0.5~6μm;

[0014] The composite foaming agent is composed of sodium rosinate, nano magnesium carbonate, and nano borate.

[0015] The nano-borate is one or a mixture of any two or more of nano-zinc borate, nano-calcium borate, and nano-manganese borate in any mass ratio.

[0016] The mass ratio of sodium rosinate, nano magnesium carbonate, and nano borate is 20~90:8~19:5~13;

[0017] The zirconate powder is one or a mixture of two of aluminum zirconate powder and calcium zirconate powder in any mass ratio;

[0018] The zirconate powder has a particle size of 0.01~1μm;

[0019] The composite mineralizer is composed of manganese borate and fluorozirconate;

[0020] The fluorozirconate is one or a mixture of any two or more of ammonium fluorozirconate, potassium fluorozirconate, and sodium fluorozirconate in any mass ratio.

[0021] The mass ratio of manganese borate to fluorozirconate is 54~117:19;

[0022] The sintering aid is one or a mixture of any two or more of sodium titanate, sodium metatitanate, and manganese titanate in any mass ratio.

[0023] The zirconium-cerium ion complex solution is composed of polyethyleneimine aqueous solution, zirconium salt, and cerium salt;

[0024] The zirconium salt is one or a mixture of any two or more of zirconium sulfate, zirconium nitrate, and zirconium chloride in any mass ratio.

[0025] The cerium salt is one or a mixture of any two or more of cerium sulfate, cerium nitrate, and cerium chloride in any mass ratio.

[0026] The mass concentration of polyethyleneimine in the polyethyleneimine aqueous solution is 9-16 wt%.

[0027] The mass ratio of the polyethyleneimine aqueous solution, zirconium salt, and cerium salt is 100~230:10~25:1~6;

[0028] The mass ratio of the composite foaming agent, deionized water, α-Al2O3 powder, pseudoboehmite, zirconate powder, composite mineralizer, sintering aid, and zirconium-cerium ion complex liquid is 19~40:80~170:160~500:45~90:8~20:8~20:5~13:30~75;

[0029] The initial stirring and dispersion are uniform, with a stirring rate of 60-90 rpm, a dispersion rate of 9000-14000 rpm, and a dispersion time of 3-6 hours;

[0030] The mixture is stirred and dispersed until uniform, with a stirring rate of 100-150 rpm, a dispersion rate of 6000-10000 rpm, and a dispersion time of 5-8 hours.

[0031] The mixture is stirred and dispersed again until it is uniform. The stirring rate is 100-150 rpm, the dispersion rate is 6000-10000 rpm, and the dispersion time is 3-7 hours.

[0032] Step 2, Molding

[0033] The slurry is injected into the extruder, and the screw speed and die diameter of the extruder are adjusted to extrude long strip-shaped catalyst carrier particles.

[0034] The original particles of the catalyst support have a cross-sectional diameter of 1~6mm and a length of 7~15mm.

[0035] Step 3: Drying and roasting

[0036] After the original catalyst support particles are thoroughly dried, they are then calcined to obtain a once-calcined catalyst support.

[0037] The drying process involves a drying temperature of 90-120℃ and a drying time of 18-39 hours.

[0038] The roasting process is carried out at a temperature of 1200~1400℃ for 3~5 hours.

[0039] Step 4: Impregnation Modification

[0040] The catalyst support that has been calcined once is placed in an impregnation solution and fully impregnated. After drying and calcination a second time, a catalyst support for the production of ethylene oxide is obtained.

[0041] The impregnation solution is composed of tin salt, tungstic acid, and deionized water;

[0042] The tin salt is one or a mixture of any two or more of stannous chloride, stannous tetrachloride, stannous sulfate, stannous sulfate, stannous nitrate, and stannous nitrate in any mass ratio;

[0043] The mass ratio of the tin salt, tungstic acid, and deionized water is 30~90:25~77:300~800;

[0044] The soaking process is described, with a soaking time of 20 to 40 hours.

[0045] The drying process involves a drying temperature of 100-140℃ and a drying time of 15-30 hours.

[0046] The secondary roasting is carried out at a temperature of 1200~1300℃ for 1~3 hours.

[0047] Compared with the prior art, the present invention achieves the following beneficial effects:

[0048] 1. To obtain a catalyst support with a better pore size distribution, namely a pore size distribution morphology with a small peak macropore size and a high proportion of medium-sized micropores (1-3 μm), this invention specifically optimizes the design of a composite foaming agent composed of sodium rosinate, nano-magnesium carbonate, and nano-borate. Sodium rosinate has a low decomposition temperature, easily decomposing at lower calcination temperatures to form medium-sized micropores and at higher calcination temperatures to form larger-sized micropores. Nano-magnesium carbonate also has a relatively low decomposition temperature, but its particle size has reached the nanoscale, thus easily forming medium-sized micropores during low-temperature calcination. Nano-borate has a higher decomposition temperature; during high-temperature calcination, nano-borate easily forms a small number of medium-sized micropores and ultramicropores with a pore size of less than 1 μm. After these ultramicropores are formed, due to the nano-boric acid... After salt decomposition, boron oxide and metal oxide are generated. Among them, boron oxide is a viscous molten glassy substance in the high-temperature calcination stage (generally above 600℃). This viscous glassy substance, together with the generated metal oxide, will block the ultramicropores with a pore size of less than 1μm. Thus, the addition of borate will not only form medium-sized micropores, but also reduce the ultramicropores with a pore size of less than 1μm. Combined with the decomposition and pore-forming effect of sodium rosinate and nano magnesium carbonate, the present invention will obtain a pore size distribution with a small peak of macropore size and a large proportion of medium-sized micropores of 1~3μm. The test data in the performance test section also show that the catalyst supports prepared in the subsequent 6 embodiments of the present invention have pore size distributions within the above-mentioned expected targets, and after silver loading, they all exhibit very good catalytic activity.

[0049] 2. The zirconate powder added in this invention, namely aluminum zirconate powder or calcium zirconate powder, are both ceramic powders with high melting points, high mechanical strength, and very low coefficients of thermal expansion. Aluminum zirconate has a melting point above 1800℃, and calcium zirconate has a melting point as high as 2200℃. The addition of these two substances mainly improves the overall mechanical properties of the catalyst support and the dimensional stability during high-temperature sintering, giving the internal microporous structure of the catalyst greater mechanical strength to maintain the stability of the microporous structure during subsequent long-term use. The data from the final performance test section of this invention also show that the silver-supported catalyst with zirconate powder added has very little catalytic performance decay after 1000 hours of operation, while the silver-supported catalyst without zirconate powder has a very large performance decay. This may be because the internal microporous structure of the silver-supported catalyst without zirconate powder has not particularly good mechanical properties and heat resistance, and is prone to microporous structure collapse during long-term use.

[0050] 3. The composite mineralizer composed of manganese borate and fluorozirconate added in this invention has the following properties: manganese borate decomposes thermally to generate boric acid and manganese oxides. Boric acid promotes the sintering and crystal growth of α-Al2O3 powder. During the calcination process, boric acid can also react with sodium ions to generate volatile sodium borate, which can eliminate the alkali metal impurities in the catalyst support and improve the mechanical properties and catalytic activity of the support. During the high-temperature stage of calcination, the fluoride ions and zirconate ions in fluorozirconate undergo a displacement reaction with alumina, promoting the transformation of alumina to the α-crystal form and the growth rate of α-Al2O3 crystals. Moreover, manganese borate and fluorozirconate have a very significant synergistic effect in reducing the transformation temperature of alumina to the α-crystal form and the growth temperature of α-Al2O3 crystals. This can reduce the calcination temperature of the catalyst support, so that a α-Al2O3 catalyst support with very high mechanical strength can be obtained at a lower sintering temperature.

[0051] 4. The sintering aids added in this invention, namely sodium titanate, sodium metatitanate, and manganese titanate, are all low-melting-point ceramicizing aids with melting points below 1200℃. After melting, they form glassy substances with a certain degree of fluidity, which can promote the flow and adhesion between α-Al2O3 powders. Moreover, these glassy substances can wet the surface of α-Al2O3 powders to a certain extent, making it easier for α-Al2O3 powders to fuse together. Therefore, they can promote the sintering density of α-Al2O3 powders at low temperatures and reduce the sintering temperature.

[0052] 5. The zirconium-cerium ion complex solution added in this invention utilizes the complexation effect of polyethyleneimine on zirconium-cerium ions combined with a high-speed dispersion process to uniformly disperse zirconium-cerium ions into the slurry. Subsequently, during the calcination process, the zirconium-cerium ions can uniformly react with alumina powder and other particulate matter. Ultimately, within the catalyst support, the oxides formed by the zirconium-cerium ions can be uniformly distributed within the catalyst support. The addition of zirconium and cerium elements can promote the catalytic activity of the silver catalyst on the α-Al2O3 support. Furthermore, the addition of zirconium and cerium elements in ionic form can promote the stability of α-Al2O3 grains from the internal lattice structure of α-Al2O3. Therefore, it can enhance the overall stability of the catalyst support, promote the stabilization effect of the catalyst support on the silver loading, and enable the silver catalyst to maintain high catalytic activity during its long service life.

[0053] 6. In this invention, tin salts and tungstic acid are used to impregnate and modify the internal pore wall surface and the external surface of the α-Al2O3 catalyst support. After impregnation and secondary calcination, the three elements of tin, tungsten, and silicon undergo a chemical sintering reaction with the alumina surface to generate a solid solution of oxides of tin, tungsten, silicon, and aluminum. During this chemical sintering reaction, the surface roughness of the pore wall of the catalyst support increases. The increased roughness increases the silver loading of the catalyst support and the solidification strength of the silver catalyst after loading. It also improves the dispersion effect of silver on the pore surface of the catalyst support. In addition, tin and tungsten easily undergo coordination effects with the silver catalyst, thus increasing the silver loading and thereby improving the catalytic activity and catalytic efficiency of the catalyst. Silicon easily forms silicon-aluminum composite oxides with aluminum, thereby improving the thermal stability of the alumina support surface and increasing the ability of the catalyst support surface to withstand high-temperature airflow erosion during long-term use, reducing the loss of the loaded silver catalyst.

[0054] 7. The catalyst support for ethylene oxide production obtained by this invention has a specific surface area of ​​2.19~2.47 m². 2 / g, strength 167~183N, water absorption 56.4~58.5%, macropore diameter peak 13.6~15.6μm, 1~3μm pores account for 96.8~99.3% of the micropore peak, silver-loaded catalyst EO space-time yield 352~371kgEO / (m 3 The EO selectivity was 91.2-93.4%, and the activity decay rate was 0.7-1.4%. Attached Figure Description

[0055] Figure 1 The image shows a scanning electron microscope (SEM) image of the cross-section of the catalyst support obtained in Example 1 for the production of ethylene oxide, magnified 1000 times.

[0056] Figure 2 The image shows a 1000x magnified cross-section of the catalyst support obtained in Example 2 for the production of ethylene oxide.

[0057] Figure 3 The image shown is a scanning electron microscope (SEM) image of the catalyst support obtained in Example 3 for the production of ethylene oxide, magnified 1000 times. Detailed Implementation

[0058] The preferred embodiments of the present invention are described below. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0059] Example 1: A method for preparing a catalyst support for the production of ethylene oxide

[0060] Step 1: Prepare slurry

[0061] The composite foaming agent and deionized water are added to a double planetary mixer. After initial stirring and uniform dispersion, α-Al2O3 powder, pseudoboehmite, zirconate powder, composite mineralizer, and sintering aid are added. After stirring and uniform dispersion, zirconium-cerium ion complex liquid is added. After stirring and uniform dispersion again, a slurry is obtained.

[0062] The particle size of the α-Al2O3 powder is 3 μm;

[0063] The composite foaming agent is composed of sodium rosinate, nano magnesium carbonate, and nano borate.

[0064] The nano-borate is nano-zinc borate;

[0065] The mass ratio of sodium rosinate, nano magnesium carbonate, and nano borate is 60:11:9;

[0066] The zirconate powder is aluminum zirconate powder;

[0067] The zirconate powder has a particle size of 0.3 μm;

[0068] The composite mineralizer is composed of manganese borate and fluorozirconate;

[0069] The fluorozirconate is ammonium fluorozirconate;

[0070] The mass ratio of manganese borate to fluorozirconate is 90:19;

[0071] The sintering aid is sodium titanate;

[0072] The zirconium-cerium ion complex solution is composed of polyethyleneimine aqueous solution, zirconium salt, and cerium salt;

[0073] The zirconium salt is zirconium sulfate;

[0074] The cerium salt is cerium sulfate;

[0075] The mass concentration of polyethyleneimine in the polyethyleneimine aqueous solution is 11 wt%.

[0076] The mass ratio of the polyethyleneimine aqueous solution, zirconium salt, and cerium salt is 200:16:5;

[0077] The mass ratio of the composite foaming agent, deionized water, α-Al2O3 powder, pseudoboehmite, zirconate powder, composite mineralizer, sintering aid, and zirconium-cerium ion complex solution is 25:130:400:65:13:13:9:55.

[0078] The initial stirring and dispersion were uniform, with a stirring rate of 80 rpm, a dispersion rate of 11,000 rpm, and a dispersion time of 5 hours.

[0079] The mixture was stirred and dispersed until uniform, with a stirring rate of 120 rpm, a dispersion rate of 9000 rpm, and a dispersion time of 7 hours.

[0080] The mixture was stirred and dispersed again at a stirring rate of 120 rpm and a dispersion rate of 9000 rpm for 6 hours.

[0081] Step 2, Molding

[0082] The slurry is injected into the extruder, and the screw speed and die diameter of the extruder are adjusted to extrude long strip-shaped catalyst carrier particles.

[0083] The original particles of the catalyst support have a cross-sectional diameter of 4 mm and a length of 11 mm.

[0084] Step 3: Drying and roasting

[0085] After the original catalyst support particles are thoroughly dried, they are then calcined to obtain a once-calcined catalyst support.

[0086] The drying process is carried out at a temperature of 110°C for 22 hours.

[0087] The roasting process is carried out at a temperature of 1300℃ for 4 hours.

[0088] Step 4: Impregnation Modification

[0089] The catalyst support that has been calcined once is placed in an impregnation solution and fully impregnated. After drying and calcination a second time, a catalyst support for the production of ethylene oxide is obtained.

[0090] The impregnation solution is composed of tin salt, tungstic acid, and deionized water;

[0091] The tin salt is stannous chloride;

[0092] The mass ratio of the tin salt, tungstic acid, and deionized water is 50:57:600.

[0093] The soaking process is described, with a soaking time of 32 hours.

[0094] The drying process is carried out at a temperature of 120°C for 25 hours.

[0095] The secondary roasting was carried out at a temperature of 1260°C for 2 hours.

[0096] Example 2: A method for preparing a catalyst support for the production of ethylene oxide

[0097] Step 1: Prepare slurry

[0098] The composite foaming agent and deionized water are added to a double planetary mixer. After initial stirring and uniform dispersion, α-Al2O3 powder, pseudoboehmite, zirconate powder, composite mineralizer, and sintering aid are added. After stirring and uniform dispersion, zirconium-cerium ion complex liquid is added. After stirring and uniform dispersion again, a slurry is obtained.

[0099] The particle size of the α-Al2O3 powder is 0.5 μm;

[0100] The composite foaming agent is composed of sodium rosinate, nano magnesium carbonate, and nano borate.

[0101] The nano-borate is nano-calcium borate;

[0102] The mass ratio of sodium rosinate, nano magnesium carbonate, and nano borate is 20:8:5.

[0103] The zirconate powder is calcium zirconate powder;

[0104] The zirconate powder has a particle size of 0.01 μm;

[0105] The composite mineralizer is composed of manganese borate and fluorozirconate;

[0106] The fluorozirconate is potassium fluorozirconate;

[0107] The mass ratio of manganese borate to fluorozirconate is 54:19;

[0108] The sintering aid is sodium metatitanate;

[0109] The zirconium-cerium ion complex solution is composed of polyethyleneimine aqueous solution, zirconium salt, and cerium salt;

[0110] The zirconium salt is zirconium nitrate;

[0111] The cerium salt is cerium nitrate;

[0112] The polyethyleneimine aqueous solution contained 9 wt% polyethyleneimine.

[0113] The mass ratio of the polyethyleneimine aqueous solution, zirconium salt, and cerium salt is 100:10:1;

[0114] The mass ratio of the composite foaming agent, deionized water, α-Al2O3 powder, pseudoboehmite, zirconate powder, composite mineralizer, sintering aid, and zirconium-cerium ion complex solution is 19:80:160:45:8:8:5:30.

[0115] The initial stirring and dispersion were uniform, with a stirring rate of 60 rpm, a dispersion rate of 9000 rpm, and a dispersion time of 3 hours.

[0116] The mixture was stirred and dispersed until uniform, with a stirring speed of 100 rpm, a dispersion speed of 6000 rpm, and a dispersion time of 5 hours.

[0117] The mixture is stirred and dispersed again at a stirring rate of 100 rpm, a dispersion rate of 6000 rpm, and a dispersion time of 3 hours.

[0118] Step 2, Molding

[0119] The slurry is injected into the extruder, and the screw speed and die diameter of the extruder are adjusted to extrude long strip-shaped catalyst carrier particles.

[0120] The original particles of the catalyst support have a cross-sectional diameter of 1 mm and a length of 7 mm.

[0121] Step 3: Drying and roasting

[0122] After the original catalyst support particles are thoroughly dried, they are then calcined to obtain a once-calcined catalyst support.

[0123] The drying process is carried out at a temperature of 90°C for 18 hours.

[0124] The roasting process is carried out at a temperature of 1200℃ for 3 hours.

[0125] Step 4: Impregnation Modification

[0126] The catalyst support that has been calcined once is placed in an impregnation solution and fully impregnated. After drying and calcination a second time, a catalyst support for the production of ethylene oxide is obtained.

[0127] The impregnation solution is composed of tin salt, tungstic acid, and deionized water;

[0128] The tin salt is tin tetrachloride;

[0129] The mass ratio of the tin salt, tungstic acid, and deionized water is 30:25:300.

[0130] The soaking process is carried out for 20 hours.

[0131] The drying process is carried out at a temperature of 100°C for 15 hours.

[0132] The secondary roasting is carried out at a temperature of 1200℃ for 1 hour.

[0133] Example 3: A method for preparing a catalyst support for the production of ethylene oxide

[0134] Step 1: Prepare slurry

[0135] The composite foaming agent and deionized water are added to a double planetary mixer. After initial stirring and uniform dispersion, α-Al2O3 powder, pseudoboehmite, zirconate powder, composite mineralizer, and sintering aid are added. After stirring and uniform dispersion, zirconium-cerium ion complex liquid is added. After stirring and uniform dispersion again, a slurry is obtained.

[0136] The particle size of the α-Al2O3 powder is 6 μm;

[0137] The composite foaming agent is composed of sodium rosinate, nano magnesium carbonate, and nano borate.

[0138] The nano-borate is nano-manganese borate;

[0139] The mass ratio of sodium rosinate, nano magnesium carbonate, and nano borate is 90:19:13.

[0140] The zirconate powder is aluminum zirconate powder;

[0141] The zirconate powder has a particle size of 1 μm;

[0142] The composite mineralizer is composed of manganese borate and fluorozirconate;

[0143] The fluorozirconate is sodium fluorozirconate;

[0144] The mass ratio of manganese borate to fluorozirconate is 117:19;

[0145] The sintering aid is manganese titanate;

[0146] The zirconium-cerium ion complex solution is composed of polyethyleneimine aqueous solution, zirconium salt, and cerium salt;

[0147] The zirconium salt is zirconium chloride;

[0148] The cerium salt is cerium chloride;

[0149] The mass concentration of polyethyleneimine in the polyethyleneimine aqueous solution is 16 wt%.

[0150] The mass ratio of the polyethyleneimine aqueous solution, zirconium salt, and cerium salt is 230:25:6;

[0151] The mass ratio of the composite foaming agent, deionized water, α-Al2O3 powder, pseudoboehmite, zirconate powder, composite mineralizer, sintering aid, and zirconium-cerium ion complex solution is 40:170:500:90:20:20:13:75.

[0152] The initial stirring and dispersion were uniform, with a stirring rate of 90 rpm, a dispersion rate of 14,000 rpm, and a dispersion time of 6 hours.

[0153] The mixture was stirred and dispersed until uniform, with a stirring speed of 150 rpm, a dispersion speed of 10,000 rpm, and a dispersion time of 8 hours.

[0154] The mixture was stirred and dispersed again at a stirring speed of 150 rpm and a dispersion speed of 10,000 rpm for 7 hours.

[0155] Step 2, Molding

[0156] The slurry is injected into the extruder, and the screw speed and die diameter of the extruder are adjusted to extrude long strip-shaped catalyst carrier particles.

[0157] The original particles of the catalyst support have a cross-sectional diameter of 6 mm and a length of 15 mm.

[0158] Step 3: Drying and roasting

[0159] After the original catalyst support particles are thoroughly dried, they are then calcined to obtain a once-calcined catalyst support.

[0160] The drying process is carried out at a temperature of 120°C for 39 hours.

[0161] The roasting process is carried out at a temperature of 1400℃ for 5 hours.

[0162] Step 4: Impregnation Modification

[0163] The catalyst support that has been calcined once is placed in an impregnation solution and fully impregnated. After drying and calcination a second time, a catalyst support for the production of ethylene oxide is obtained.

[0164] The impregnation solution is composed of tin salt, tungstic acid, and deionized water;

[0165] The tin salt is tin sulfate;

[0166] The mass ratio of the tin salt, tungstic acid, and deionized water is 90:77:800;

[0167] The soaking process is described, with a soaking time of 40 hours.

[0168] The drying process is carried out at a temperature of 140°C for 30 hours.

[0169] The secondary roasting was carried out at a temperature of 1300℃ for 3 hours.

[0170] Example 4: A method for preparing a catalyst support for the production of ethylene oxide

[0171] Steps 1, 2, and 3 are the same as in Example 1;

[0172] Step 4: Impregnation Modification

[0173] The tin salt is stannous sulfate, and other operations are the same as in Example 1.

[0174] Example 5: A method for preparing a catalyst support for the production of ethylene oxide

[0175] Steps 1, 2, and 3 are the same as in Example 1;

[0176] Step 4: Impregnation Modification

[0177] The tin salt is stannous nitrate, and other operations are the same as in Example 1.

[0178] Example 6: A method for preparing a catalyst support for the production of ethylene oxide

[0179] Steps 1, 2, and 3 are the same as in Example 1;

[0180] Step 4: Impregnation Modification

[0181] The tin salt is tin nitrate, and other operations are the same as in Example 1.

[0182] Comparative Example 1: Based on Example 1, in step 1, the preparation of the slurry, the composite foaming agent consists only of sodium rosinate, that is, 11 parts of nano magnesium carbonate and 9 parts of nano borate are replaced by 20 parts of sodium rosinate in equal amounts. The specific operation is as follows:

[0183] Step 1: Prepare slurry

[0184] Based on Example 1, 11 parts of nano magnesium carbonate and 9 parts of nano borate were replaced with 20 parts of sodium rosinate, that is, the composite foaming agent was composed only of sodium rosinate, and other operations were the same as in Example 1.

[0185] Steps 2, 3, and 4 are the same as in Example 1.

[0186] Comparative Example 2: Based on Example 1, in step 1, the composite foaming agent in the preparation of the slurry consists only of nano-magnesium carbonate and nano-borate. 60 parts of sodium rosinate were replaced with 33 parts of nano-magnesium carbonate and 27 parts of nano-borate in an equal ratio of 11:9. The specific operation is as follows:

[0187] Step 1: Prepare slurry

[0188] Based on Example 1, 60 parts of sodium rosinate were replaced with 33 parts of nano magnesium carbonate and 27 parts of nano borate in an equal ratio of 11:9. That is, the composite foaming agent is composed only of nano magnesium carbonate and nano borate. Other operations are the same as in Example 1.

[0189] Steps 2, 3, and 4 are the same as in Example 1.

[0190] Comparative Example 3: Based on Example 1, in step 1, preparing the slurry, zirconate powder was not added. Instead, 13 parts of zirconate powder were replaced with 13 parts of deionized water in equal amounts. The specific operation is as follows:

[0191] Step 1: Prepare slurry

[0192] Based on Example 1, 13 parts of zirconate powder were replaced with 13 parts of deionized water in equal amounts, and other operations were the same as in Example 1;

[0193] Steps 2, 3, and 4 are the same as in Example 1.

[0194] Comparative Example 4: Based on Example 1, in step 1, the preparation of the slurry, without adding the composite mineralizer, 13 parts of the composite mineralizer were replaced with 13 parts of deionized water in equal amounts. The specific operation is as follows:

[0195] Step 1: Prepare slurry

[0196] Based on Example 1, 13 parts of composite mineralizer were replaced with 13 parts of deionized water in equal amounts, and other operations were the same as in Example 1;

[0197] Steps 2, 3, and 4 are the same as in Example 1.

[0198] Comparative Example 5: Based on Example 1, in step 1, the composite mineralizer in the slurry preparation consisted only of manganese borate. 13 parts of the composite mineralizer were replaced with an equal amount of manganese borate. The specific operation is as follows:

[0199] Step 1: Prepare slurry

[0200] Based on Example 1, 13 parts of composite mineralizer were replaced with 13 parts of manganese borate in equal amounts, that is, the composite mineralizer consisted only of manganese borate, and other operations were the same as in Example 1.

[0201] Steps 2, 3, and 4 are the same as in Example 1.

[0202] Comparative Example 6: Based on Example 1, in step 1, the composite mineralizer in the slurry preparation consisted only of fluorozirconate. 13 parts of the composite mineralizer were replaced with 13 parts of fluorozirconate in equal amounts. The specific operation is as follows:

[0203] Step 1: Prepare slurry

[0204] Based on Example 1, 13 parts of the composite mineralizer were replaced with 13 parts of fluorozirconate, that is, the composite mineralizer consisted only of fluorozirconate, and other operations were the same as in Example 1.

[0205] Steps 2, 3, and 4 are the same as in Example 1.

[0206] Comparative Example 7: Based on Example 1, in step 1, the preparation of the slurry, no sintering aid was added. Instead, 9 parts of sintering aid were replaced with 9 parts of deionized water in equal amounts. The specific operation is as follows:

[0207] Step 1: Prepare slurry

[0208] Based on Example 1, 9 parts of sintering aid were replaced with 9 parts of deionized water in equal amounts, and other operations were the same as in Example 1;

[0209] Steps 2, 3, and 4 are the same as in Example 1.

[0210] Comparative Example 8: Based on Example 1, in step 1, the zirconium-cerium ion complex solution was not added to the slurry. Instead, based on the solid content of the zirconium-cerium ion complex solution, 55 parts of the zirconium-cerium ion complex solution were replaced with an equal amount of 44.3 parts of deionized water and 10.7 parts of α-Al₂O₃ powder. The specific operation is as follows:

[0211] Step 1: Prepare slurry

[0212] Based on Example 1, 55 parts of zirconium-cerium ion complex solution were replaced with 44.3 parts of deionized water and 10.7 parts of α-Al2O3 powder in equal amounts, and other operations were the same as in Example 1;

[0213] Steps 2, 3, and 4 are the same as in Example 1.

[0214] Comparative Example 9: Based on Example 1, without performing step 4 (impregnation modification) and step 3 (drying and calcination), a catalyst support for the production of ethylene oxide was directly obtained. The specific operation is as follows:

[0215] Steps 1 and 2 are the same as in Example 1;

[0216] Step 3: Drying and roasting

[0217] After the original catalyst support particles were thoroughly dried, they were then calcined to obtain a catalyst support for the production of ethylene oxide. Other operations were the same as in Example 1.

[0218] Step 4, impregnation modification, is not performed.

[0219] Comparative Example 10: Based on Example 1, in step 4, impregnation modification, tin salt was not added to the impregnation solution. Instead, 50 parts of tin salt were replaced with 50 parts of tungstic acid. The specific operation is as follows:

[0220] Steps 1, 2, and 3 are the same as in Example 1;

[0221] Step 4: Impregnation Modification

[0222] Replace 50 parts of tin salt with 50 parts of tungstic acid, and perform the other operations as in Example 1.

[0223] Comparative Example 11: Based on Example 1, in step 4, impregnation modification, tungstic silicic acid was not added to the impregnation solution. Instead, 57 parts of tungstic silicic acid were replaced with 57 parts of tin salt. The specific operation is as follows:

[0224] Steps 1, 2, and 3 are the same as in Example 1;

[0225] Step 4: Impregnation Modification

[0226] Replace 57 parts of tungstic acid with 57 parts of tin salt, and perform the other operations as in Example 1.

[0227] Performance testing:

[0228] The catalyst supports obtained in Examples 1-6 and Comparative Examples 1-11 for the production of ethylene oxide were tested for relevant parameters according to the following methods:

[0229] 1. Specific surface area: The specific surface area was measured using an ASAP 2020 Automated System specific surface area analyzer from Micron Instruments, Inc., USA. The sample was degassed at 623K for 5 hours before adsorption.

[0230] 2. Strength: The strength of the catalyst support was tested using the DLⅡ type intelligent particle strength tester from Dalian Chemical Research and Design Institute. Thirty support samples were randomly selected, and the average value was taken.

[0231] 3. Water absorption rate: Weigh a certain amount of catalyst support (mass m1), boil it in boiling water for 1 hour, then remove the catalyst support and stand it upright on a damp gauze with appropriate moisture content to remove excess water from the surface of the catalyst support. Finally, weigh the mass m2 of the catalyst support after water adsorption. The water absorption rate is calculated using the formula: Water absorption rate = (m2 - m1) / (m1 × ρ) 水 )×100%, where ρ 水 This refers to the density of water at the temperature and atmospheric pressure used to determine the water absorption rate;

[0232] 4. Pore size distribution: The pore size distribution of the catalyst support was determined using an Autopore Ⅳ-9510 mercury porosimeter from Micron Instruments, Inc., USA.

[0233] For the catalyst supports obtained in Examples 1-6 and Comparative Examples 1-11 for the production of ethylene oxide, the silver loading process and catalytic activity tests were carried out as follows:

[0234] Silver loading operation on catalyst support:

[0235] Weigh 140 g of silver nitrate and dissolve it in 150 mL of deionized water. Weigh 64 g of ammonium oxalate and dissolve it in 520 mL of deionized water. Dissolve thoroughly to obtain silver nitrate and ammonium oxalate solutions. Mix these two solutions under vigorous stirring to form a white silver oxalate precipitate. Aging for at least 30 minutes, filter, and wash the precipitate with deionized water until no nitrate ions remain, obtaining a silver oxalate filter cake. Then, dissolve 70 g of ethylenediamine in 75 g of deionized water and add the obtained oxalate filter cake. Continue stirring until the silver oxalate is completely dissolved. Then, add 2.58 g of cesium nitrate and 6.22 g of barium acetate sequentially. 0.86 g of ammonium perrhenate and deionized water were added to make the total mass of the solution reach 400 g, and an impregnation solution was obtained. A total of 17 impregnation solutions with a mass of 400 g were prepared according to the above method. Then, for all examples and comparative examples, 20 g of each catalyst support sample was taken and placed in a container that could be vacuumed. The vacuum was drawn to 10 mmHg, and then 400 g of impregnation solution was drawn into the container under negative pressure. After impregnation for 30 minutes, the vacuum was removed, the material was discharged and filtered to remove the impregnation solution. The filtered solid was heated in a hot air stream at 450°C for 3 minutes and then cooled to room temperature to obtain the corresponding silver-supported catalyst.

[0236] Catalytic performance test:

[0237] The catalytic performance of the silver-loaded catalyst was tested using a microreactor. The inner diameter of the reaction tube was 4 mm, the catalyst loading mass was 500 mg, and the feed gas composition was ethylene with a molar concentration of 28%, oxygen with a molar concentration of 7.4%, carbon dioxide with a molar concentration of 1%, and 2 × 10⁻⁶ ppm. -6 The reaction mixture consisted of 2.5% dichloroethane (an inhibitor), 2.5% ethylene oxide, and the remainder (less than 100%) was supplemented by nitrogen as a balance gas. The reaction pressure was 2 MPa, the reaction temperature was 225 °C, and the mass hourly space velocity (HHSV) was 6000 h⁻¹. -1 The composition of the gas after the reaction was analyzed by gas chromatography. The catalytic performance was characterized by three indicators: space-time yield, ethylene oxide selectivity, and catalytic activity decay rate. The ethylene oxide selectivity and catalytic activity decay rate were calculated using the following formulas:

[0238] Ethylene oxide selectivity = ΔEO ÷ (ΔEO + 0.5 × ΔCO2) × 100%, where ΔEO is the concentration difference of ethylene oxide in the outlet reaction tail gas and the inlet feed gas, and ΔCO2 is the concentration difference of carbon dioxide in the outlet reaction tail gas and the inlet feed gas.

[0239] Activity decay rate = 100% - (EO space-time yield after 1000 hours of continuous reaction ÷ EO space-time yield after initial stabilization) × 100%

[0240] The test results are shown in Table 1:

[0241] Table 1

[0242]

[0243] As can be seen from the data in Table 1, the catalyst supports obtained in Examples 1-6 for the production of ethylene oxide have a specific surface area of ​​approximately 2.2~2.3 m². 2 The pore size distribution shows that the peak value of macropores is below 15.6 μm, and the proportion of micropores of 1~3 μm is greater than 96.8% of the small pore peak. This indicates that the catalyst support obtained by this invention has a relatively concentrated pore size distribution, with no ineffective macropores of tens of micrometers or larger, and a very small proportion of ultramicropores smaller than 1 μm. This pore size distribution can ensure the loading of silver catalyst on the catalyst support, and can also effectively avoid the problems of support damage and catalyst deactivation caused by excessive accumulation of reaction heat in too many small-pore micropores. Due to the small number of macropores, the strength of the catalyst support is also above 160 N. The catalytic activity test after silver loading also shows that the space-time yield of EO is 350 kgEO / (m 3 The EO selectivity is greater than 91% and the catalytic activity decay rate after 1000 hours of operation is less than 1.5%. These data fully demonstrate that the catalyst support prepared by this invention for the production of ethylene oxide has advantages such as good pore size distribution, high water absorption, high silver loading, high mechanical strength, and good EO selectivity. The composite foaming agent added in Comparative Example 1 contains only sodium rosinate, while the composite foaming agent added in Comparative Example 2 contains only nano-magnesium carbonate and nano-borate. The specific surface area of ​​Comparative Example 1 is reduced to 1.07 m². 2 / g, while the specific surface area of ​​Comparative Example 2 increased to 4.64 m². 2 Regarding pore size distribution, in Comparative Example 1, the peak macropore size increased to 25.8 μm, and the proportion of 1-3 μm micropores in the small pore peak decreased to 67.9%. In Comparative Example 2, the peak macropore size decreased to 9.3 μm, and the proportion of 1-3 μm micropores in the small pore peak decreased to 81.2%. It is evident that Comparative Example 1 showed an increase in the number of macropores and a decrease in the number of micropores, while Comparative Example 2 showed a decrease in the number of macropores and an increase in the number of micropores smaller than 1 μm. This indicates that sodium rosinate foaming primarily forms macropores, while nano-magnesium carbonate and nano-... Nano-borate foaming readily forms micropores with a pore size of less than 3 μm. The composite foaming agent composed of sodium rosinate, nano-magnesium carbonate, and nano-borate exhibits excellent synergistic effects, effectively inhibiting the formation of macropores and ultramicropores smaller than 1 μm. This results in a better pore size distribution and a relatively optimal specific surface area for the catalyst support. The catalytic performance reflects the influence of pore size distribution on the catalytic effect of the silver-supported catalyst. The EO space-time yields of Comparative Examples 1 and 2 decreased to 186 kg EO / (m²). 3 ·h) and 207kgEO / (m 3The activity decay rate also increased sharply to 11.6% and 13.9% in Comparative Example 4 and Comparative Example 6, respectively. This indicates that the composite foaming agent used in this invention has a very good effect on optimizing and regulating the pore size of the catalyst support. It can maintain the necessary specific surface area, increase the silver loading, and ensure the high catalytic activity of the catalyst, while effectively reducing the number of micropores and avoiding the problem of excessive accumulation of reaction heat inside the catalyst. In Comparative Example 3, no zirconate powder was added. The specific surface area, pore size distribution, water absorption rate, and initial catalytic activity of Comparative Example 3 were basically similar to those of Example 1. However, the activity decay rate of Comparative Example 3 increased significantly after 1000 hours of operation. This may be because the zirconate powder mainly plays the role of enhancing the mechanical strength and high temperature resistance of the catalyst support. It can maintain the high strength and high heat resistance of the catalyst support during long-term use and extend the service life of the catalyst support. In Comparative Example 4, no composite mineralizer was added. The mineralizers added to Comparative Examples 5 and 6 were only manganese borate and fluorozirconate, respectively. The specific surface area of ​​these three comparative examples decreased to 1.25~1.59m². 2 / g, the corresponding water absorption rate also decreased to 48.7~52.2%, the strength decreased to 139~156N, and in terms of pore size distribution, the peak value of macropores in the three comparative examples increased to 18.7~20.6μm, while the proportion of 1~3μm pores to the micropore peak decreased to 86.8~92.9%. Correspondingly, in terms of catalyst activity, the EO space-time yield decreased to 284~301kgEO / (m 3 The selectivity decreased to 80.5-84.8%, and the activity decay rate increased to 7.2-9.7%, indicating that the composite mineralizer can promote the sintering and densification of α-Al2O3 powder, effectively increase the specific surface area of ​​the catalyst support, optimize the pore size distribution, and improve the support strength, thereby improving the catalytic activity of the silver-supported catalyst. Moreover, manganese borate and fluorozirconate have a good synergistic effect in promoting the densification and sintering of α-Al2O3 powder. In Comparative Example 7, no sintering aid was added, and the specific surface area of ​​Comparative Example 7 decreased to 1.43 m². 2 / g, strength decreased to 148 N, water absorption decreased to 53.4%, macropore diameter peak increased to 19.9 μm, and the proportion of 1~3 μm pores in the micropore peak decreased to 90.6%. Correspondingly, the catalytic activity of the silver-supported catalyst also decreased significantly, and the EO space-time yield decreased to 308 kgEO / (m 3 The selectivity decreased to 81.9% and the activity decay rate increased to 9.4% in Comparative Example 7 (·h), indicating that without the addition of sintering aids, α-Al₂O₃ powder is difficult to achieve relatively dense sintering at lower temperatures. This leads to a decrease in the specific surface area, strength, and pore size distribution of the catalyst support, which in turn causes a decrease in water absorption and silver loading. Ultimately, the silver-loaded catalyst obtained in Comparative Example 7 showed a significant decrease in catalytic activity. In Comparative Example 8, without the addition of zirconium-cerium ion complexing liquid, the specific surface area increased to 2.89 m². 2 / g, strength increased to 203N, water absorption rate did not change much, macropore diameter peak decreased to 12.5μm, and the proportion of 1~3μm pores to micropore peak increased to 99.7%. This indicates that the zirconium-cerium ion complex solution has a slight effect on pore size distribution. This may be due to the fact that polyethyleneimine contained in the zirconium-cerium ion complex solution can form a certain amount of larger pores during the calcination process. Polyethyleneimine has a low decomposition temperature and can form some micropores with larger pore sizes. Without the addition of zirconium-cerium ion complex solution, the pore-forming effect of polyethyleneimine is lacking, and the specific surface area of ​​the catalyst support increases. Although the specific surface area, pore size distribution and water absorption rate of Comparative Example 8 are not significantly different from those of Example 1, the catalytic activity of Comparative Example 8 is greatly reduced, and the EO space-time yield decreases to 297kgEO / (m 3 The selectivity decreased to 80.3% and the activity decay rate increased to 12.9%, which may be due to the synergistic effect between zirconium and cerium and the supported silver catalyst, which can effectively promote the catalytic activity of the silver catalyst. Comparative Example 9 was not impregnated, and Comparative Examples 10 and 11 were impregnated without the addition of tin salt and tungstic acid, respectively. The specific surface area, strength, water absorption rate, and pore size distribution of these three comparative examples were not significantly different from those of Example 1. This indicates that the impregnation modification process has little effect on the internal structure of the catalyst support after the first calcination. However, the catalytic activity of these three comparative examples decreased significantly. Among them, the EO space-time yield of Comparative Example 9, which was not impregnated, decreased to 265 kgEO / (m²). 3 The selectivity decreased to 74.7% and the activity decay rate increased to 15.2%, indicating that the tin and tungsten-silicon elements introduced on the surface of the micropores of the catalyst support during the impregnation modification process play a crucial role in improving the activity of the silver-supported catalyst. Moreover, the test data of Comparative Example 10 and Comparative Example 11 also show that the tin salt and tungsten-silica used in the impregnation modification jointly promoted the catalytic activity of the silver-supported catalyst.

[0244] Appendix Figure 1 Appendix Figure 2 Appendix Figure 3 The images shown are scanning electron microscope (SEM) images of the catalyst supports used for producing ethylene oxide obtained in Examples 1, 2, and 3, magnified 1000 times. Comparing these three images, it can be seen that the micropore size distribution is basically similar and relatively uniform. The pore size of most micropores is within a few micrometers, and there are almost no large pores. Micropores with particularly small pore sizes, i.e., pores below the micrometer level, are basically not visible. This indicates that the raw material composition and preparation process used in this invention can precisely control the pore size distribution of the catalyst support.

[0245] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a catalyst support for the production of ethylene oxide, characterized in that: The method for preparing the catalyst support for producing ethylene oxide includes four steps: preparing a slurry, molding, drying and calcining, and impregnation modification. To prepare the slurry, the composite foaming agent and deionized water are added to a double planetary mixer. After initial stirring and uniform dispersion, α-Al2O3 powder, pseudoboehmite, zirconate powder, composite mineralizer, and sintering aid are added. After stirring and uniform dispersion, zirconium-cerium ion complex liquid is added. After stirring and uniform dispersion again, the slurry is obtained. The composite foaming agent is composed of sodium rosinate, nano magnesium carbonate, and nano borate. The composite mineralizer is composed of manganese borate and fluorozirconate; The sintering aid is one or a mixture of any two or more of sodium titanate, sodium metatitanate, and manganese titanate in any mass ratio. The zirconium-cerium ion complex solution is composed of polyethyleneimine aqueous solution, zirconium salt, and cerium salt; The molding process involves injecting slurry into an extruder, adjusting the screw speed and die diameter of the extruder, and extruding to obtain elongated catalyst carrier particles. The drying and calcination process involves thoroughly drying the original catalyst support particles and then calcining them to obtain a once-calcined catalyst support. The impregnation modification involves immersing the catalyst support, which has been calcined once, in an impregnation solution. After thorough impregnation, the catalyst support is dried and calcined a second time to obtain a catalyst support for the production of ethylene oxide. The impregnation solution is composed of tin salt, tungstic acid, and deionized water; The secondary roasting is carried out at a temperature of 1200~1300℃ for 1~3 hours.

2. The method for preparing a catalyst support for the production of ethylene oxide according to claim 1, characterized in that: The particle size of the α-Al2O3 powder is 0.5~6μm; The nano-borate is one or a mixture of any two or more of nano-zinc borate, nano-calcium borate, and nano-manganese borate in any mass ratio. The zirconate powder is one or a mixture of two of aluminum zirconate powder and calcium zirconate powder in any mass ratio; The zirconate powder has a particle size of 0.01~1μm.

3. The method for preparing a catalyst support for the production of ethylene oxide according to claim 1, characterized in that: The fluorozirconate is one or a mixture of any two or more of ammonium fluorozirconate, potassium fluorozirconate, and sodium fluorozirconate in any mass ratio. The zirconium salt is one or a mixture of any two or more of zirconium sulfate, zirconium nitrate, and zirconium chloride in any mass ratio. The cerium salt is one or a mixture of any two or more of cerium sulfate, cerium nitrate, and cerium chloride in any mass ratio. The mass concentration of polyethyleneimine in the aqueous solution is 9-16 wt%.

4. The method for preparing a catalyst support for the production of ethylene oxide according to claim 1, characterized in that: The original particles of the catalyst support have a cross-sectional diameter of 1~6mm and a length of 7~15mm; The tin salt is one or a mixture of any two or more of stannous chloride, stannous tetrachloride, stannous sulfate, stannous sulfate, stannous nitrate, and stannous nitrate in any mass ratio.

5. The method for preparing a catalyst support for the production of ethylene oxide according to claim 1, characterized in that: The mass ratio of sodium rosinate, nano magnesium carbonate, and nano borate is 20~90:8~19:5~13; The mass ratio of manganese borate to fluorozirconate is 54~117:19; The mass ratio of the polyethyleneimine aqueous solution, zirconium salt, and cerium salt is 100~230:10~25:1~6; The mass ratio of the composite foaming agent, deionized water, α-Al2O3 powder, pseudoboehmite, zirconate powder, composite mineralizer, sintering aid, and zirconium-cerium ion complex liquid is 19~40:80~170:160~500:45~90:8~20:8~20:5~13:30~75.

6. The method for preparing a catalyst support for the production of ethylene oxide according to claim 1, characterized in that: The mass ratio of the tin salt, tungstic acid, and deionized water is 30~90:25~77:300~800.

7. A catalyst support for the production of ethylene oxide prepared by the preparation method according to any one of claims 1-6.

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