阅读说明：本技术 一种加氢脱硫催化剂的制备方法 (Preparation method of hydrodesulfurization catalyst ) 是由 隋宝宽 季洪海 彭冲 吕振辉 于 2019-04-17 设计创作，主要内容包括：本发明公开了一种加氢脱硫催化剂的制备方法。该方法包括：(1)将物理扩孔剂依次吸附铝盐溶液和碱性溶液,然后干燥、焙烧制得改性物理扩孔剂；(2)将步骤(1)所得的改性物理扩孔剂、拟薄水铝石混捏成型、干燥、焙烧,得到中间体；(3)将步骤(2)所得的中间体浸入碳酸氢铵溶液中,然后密封热处理,热处理后物料经干燥、焙烧制得改性氧化铝基载体；(4)将加氢活性金属组分浸渍液浸渍步骤(3)所得的改性氧化铝基载体,干燥、焙烧制得加氢脱硫催化剂。该方法制备的加氢脱硫催化剂具有大分子扩散性能好、脱硫能力强,残炭去除率高等特性。(The invention discloses a preparation method of a hydrodesulfurization catalyst. The method comprises the following steps: (1) sequentially adsorbing an aluminum salt solution and an alkaline solution by using a physical pore-enlarging agent, and then drying and roasting to obtain a modified physical pore-enlarging agent; (2) kneading the modified physical pore-expanding agent obtained in the step (1) and pseudo-boehmite, molding, drying and roasting to obtain an intermediate; (3) immersing the intermediate obtained in the step (2) into an ammonium bicarbonate solution, then carrying out sealing heat treatment, drying and roasting the heat-treated material to obtain a modified alumina-based carrier; (4) and (3) impregnating the modified alumina-based carrier obtained in the step (3) with a hydrogenation active metal component impregnation solution, drying and roasting to obtain the hydrodesulfurization catalyst. The hydrodesulfurization catalyst prepared by the method has the characteristics of good macromolecular diffusion performance, strong desulfurization capability, high carbon residue removal rate and the like.)

1. A preparation method of a hydrodesulfurization catalyst is characterized by comprising the following steps: the method comprises the following steps:

(1) sequentially adsorbing an aluminum salt solution and an alkaline solution by using a physical pore-enlarging agent, and then drying and roasting to obtain a modified physical pore-enlarging agent;

(2) kneading the modified physical pore-expanding agent obtained in the step (1) and pseudo-boehmite, molding, drying and roasting to obtain an intermediate;

(3) immersing the intermediate obtained in the step (2) into an ammonium bicarbonate solution, then carrying out sealing heat treatment, drying and roasting the heat-treated material to obtain a modified alumina-based carrier;

(4) and (3) impregnating the modified alumina-based carrier obtained in the step (3) with a hydrogenation active metal component impregnation solution, drying and roasting to obtain the hydrodesulfurization catalyst.

2. The method of claim 1, wherein: the physical pore-enlarging agent in the step (1) is one or more of activated carbon and wood chips, and the particle size of the physical pore-enlarging agent is 3-7 mu m.

3. The method of claim 1, wherein: the aluminum salt solution in the step (1) is one or a mixture of aluminum chloride solution, aluminum sulfate solution and aluminum nitrate solution, preferably aluminum nitrate solution, the mass concentration of the aluminum salt solution is 5% -10% calculated by alumina, the amount of the aluminum salt solution is used for completely immersing the physical pore-expanding agent, and the immersion time is 1-4 hours.

4. The method of claim 1, wherein: the alkaline solution in the step (1) is a sodium hydroxide solution, ammonia water and a sodium metaaluminate solution, preferably ammonia water, the mass concentration of the alkaline solution is 10-40%, the volume consumption of the alkaline solution is 10-20 times of the volume of the physical pore-expanding agent, and the impregnation time is 1-4 hours.

5. The method of claim 1, wherein: the drying conditions in the step (1) are as follows: drying at 100 ℃ and 140 ℃ for 1-4 hours, wherein the roasting conditions are as follows: roasting at 400-500 ℃ for 3-6 hours, wherein the roasting is carried out under the protection of inert atmosphere, and the inert atmosphere is preferably nitrogen.

6. The method of claim 1, wherein: the adding amount of the modified physical pore-expanding agent in the step (2) is 10-20 wt% of the weight of the intermediate.

7. The method of claim 1, wherein: the drying in the step (2) is drying at the temperature of 100-140 ℃ for 1-4 hours, the roasting is roasting at the temperature of 600-750 ℃ for 3-6 hours, and the roasting is carried out in the air atmosphere.

8. The method of claim 1, wherein: the mass ratio of the using amount of the ammonium bicarbonate solution in the step (3) to the added intermediate is 4:1-7:1, and the mass concentration of the ammonium bicarbonate solution is 15-25%.

9. The method of claim 1, wherein: the sealing heat treatment temperature in the step (3) is 120-160 ℃, the constant temperature treatment time is 4-8 hours, and the heating rate is 5-20 ℃/min.

10. The method of claim 1, wherein: and (3) sealing pretreatment is carried out before sealing heat treatment, the pretreatment temperature is 60-100 ℃, the constant temperature treatment time is 2-4 hours, the temperature rise rate before pretreatment is 10-20 ℃/min, the temperature rise rate after pretreatment is 5-10 ℃/min, and the temperature rise rate after pretreatment is at least 3 ℃/min lower than that before pretreatment, preferably at least 5 ℃/min lower.

11. The method of claim 1, wherein: the drying temperature in the step (3) is 160 ℃ and the drying time is 4-8 hours, the roasting temperature is 550 ℃ and 650 ℃ and the roasting time is 4-6 hours.

12. The method of claim 1, wherein: the hydrogenation active component impregnation liquid in the step (4) is a solution containing VIB group and/or VIII group metals, the VIB group metals are selected from one or more of W, Mo, the VIII group metals are selected from one or more of Co and Ni, the concentration of the VIB group metals is 8-17.5g/100mL calculated by metal oxides, the concentration of the VIII group metals is 2.5-5.0g/100mL calculated by metal oxides, and equal-volume impregnation or supersaturation impregnation is adopted during impregnation.

13. The method of claim 1, wherein: the drying temperature in the step (4) is 80-160 ℃, the drying time is 6-10 hours, and the roasting is carried out for 4-8 hours at the temperature of 450-550 ℃.

14. A residue hydrodesulphurisation catalyst prepared by a process as claimed in any of claims 1 to 13.

15. The catalyst of claim 14, wherein: the catalyst comprises a modified alumina-based carrier and a hydrogenation active metal component, wherein the modified alumina-based carrier comprises main modified alumina and rod-shaped modified alumina, the main modified alumina is modified alumina with micron-sized pore channels, and at least part of the rod-shaped modified alumina is distributed on the outer surface of the main alumina and in the micron-sized pore channels with the pore diameter D of 3-7 mu m.

16. The catalyst of claim 14, wherein: based on the weight of the hydrodesulfurization catalyst, the total content of the hydrogenation active metal components is 10% to 25%, preferably the content of the VIB group metal is 10% to 20% calculated by oxide, and the content of the VIII group metal is 3% to 10% calculated by oxide.

17. The catalyst of claim 14, wherein: the rodlike modified alumina is basically distributed on the outer surface of the main body modified alumina and in the micron-sized pore channels.

18. The catalyst of claim 14, wherein: in the modified alumina-based carrier, the length of the rod-shaped modified alumina in the micron-sized pore channel is mainly 0.3D-0.9D, and the length of the rod-shaped modified alumina on the outer surface is mainly 3-8 μm.

19. The catalyst of claim 14, wherein: the diameter of the rod-shaped modified alumina is 80-260 nm.

20. The catalyst of claim 14, wherein: in the modified alumina-based carrier, at least one end of at least part of rod-shaped modified alumina is attached to the micron-sized pore channel wall of the main modified alumina, preferably at least one end of at least part of rod-shaped modified alumina is combined with the micron-sized pore channel wall to form a whole with the main modified alumina, and further preferably at least one end of the rod-shaped modified alumina in the micron-sized pore channel is combined with the micron-sized pore channel wall to form a whole with the main modified alumina.

21. The catalyst of claim 14, wherein: in the modified alumina-based carrier, one end of at least part of rod-shaped modified alumina is attached to the outer surface of the main modified alumina, preferably, one end of at least part of rod-shaped modified alumina is combined with the outer surface of the main modified alumina, and the other end of at least part of rod-shaped modified alumina extends outwards and is integrated with the main modified alumina.

22. The catalyst of claim 14, wherein: in the modified alumina-based carrier, the coverage rate of the rod-shaped modified alumina in the micron-sized pore canal of the main body modified alumina accounts for 75-95%, and the coverage rate of the rod-shaped modified alumina on the outer surface of the main body modified alumina accounts for 70-95%.

23. The catalyst of claim 14, wherein: the specific surface area of the catalyst is 220-320m²(iv)/g, pore volume of 0.8-1.8mL/g, crush strength of 15-22N/mm.

24. The catalyst of claim 14, wherein: in the catalyst, the pores formed by the rod-shaped modified alumina in a disordered and staggered manner are concentrated between 100-600 nm.

25. The catalyst of claim 14, wherein: the pore distribution of the catalyst is as follows: the pore volume of the pores with the pore diameter of less than 10nm is less than 20 percent of the total pore volume, the pore volume of the pores with the pore diameter of 10-30nm is 40-60 percent of the total pore volume, the pore volume of the pores with the pore diameter of 100-600nm is 12-25 percent of the total pore volume, and the pore volume of the pores with the pore diameter of more than 1000nm is less than 5 percent.

Technical Field

The invention relates to the field of catalyst preparation, in particular to a preparation method of a residual oil hydrodesulfurization catalyst.

Background

With the increasing weight and quality of petroleum, petroleum processing is more and more difficult. Heavy oil residues contain a large amount of sulfur, most of which is present in asphaltenes, and are difficult to remove. Hydrodesulfurization has been regarded as an important process in petroleum refining and synthetic ammonia production using petroleum as a raw material. However, in recent years, the quality of petroleum is getting heavier and worse, the requirements on the quality of products are stricter, and the requirements on the feeding materials in the subsequent process are more and more strict. In addition, since the 21 st century, people's awareness of environmental protection has been increasing, and environmental legislation has become stricter and stricter, and NO in exhaust gas discharged from motor vehicles_x、SO_xAnd the limitation of the aromatic content is more severe. In 2010, a sulfur content of less than 10 μ g/g was required. For the above reasons, hydrodesulfurization techniques for gasoline and diesel are moving toward the processing of high sulfur oils and the production of ultra-low sulfur clean petroleum fuels.

CN1123626C discloses a heavy oil and residual oil hydrotreating catalyst and its preparation method, in particular a heavy oil hydrodesulfurization catalyst and its preparation method. The method adopts a cheap and environment-friendly titanium-containing aluminum hydroxide carrier, promotes metal dispersion through the kneading process of materials such as titanium-containing aluminum hydroxide and metal salts, and prepares the catalyst through extrusion molding and high-temperature activation after all the materials are kneaded into plastic bodies. The catalyst prepared by the method has small aperture, is not beneficial to the entry of residual oil reactant molecules, and in addition, the hydrogenation carbon residue removal activity of the catalyst needs to be further improved.

CN1205314C discloses a preparation method of a heavy oil hydrodemetallization and desulfurization catalyst, wherein a carrier is compounded by two kinds of alumina, one of the two kinds of alumina is alumina powder calcined at the high temperature of 1100 ℃, the method can form more pore channels with the diameter of more than 15nm, and the pore channels have penetrability, but are too small for asphaltene micelles to be beneficial to residual oil hydrodesulfurization and hydrodecarbonization reactions.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a preparation method of a hydrodesulfurization catalyst. The hydrodesulfurization catalyst prepared by the method has the characteristics of good macromolecular diffusion performance, strong desulfurization capability, high carbon residue removal rate and the like. The hydrodesulfurization catalyst is particularly suitable for residual oil hydrodesulfurization treatment process.

One aspect of the present invention provides a method for preparing a hydrodesulfurization catalyst, comprising:

(1) sequentially adsorbing an aluminum salt solution and an alkaline solution by using a physical pore-enlarging agent, and then drying and roasting to obtain a modified physical pore-enlarging agent;

(2) kneading the modified physical pore-expanding agent obtained in the step (1) and pseudo-boehmite, molding, drying and roasting to obtain an intermediate;

(3) immersing the intermediate obtained in the step (2) into an ammonium bicarbonate solution, then carrying out sealing heat treatment, drying and roasting the heat-treated material to obtain a modified alumina-based carrier;

(4) and (3) impregnating the modified alumina-based carrier obtained in the step (3) with a hydrogenation active metal component impregnation solution, drying and roasting to obtain the hydrodesulfurization catalyst.

In the method, the physical pore-enlarging agent in the step (1) can be one or more of activated carbon and wood chips, and the particle size of the physical pore-enlarging agent is about 3-7 mu m.

In the method of the present invention, the aluminum salt solution in step (1) may be one or a mixture of several of aluminum chloride solution, aluminum sulfate solution and aluminum nitrate solution, preferably aluminum nitrate solution, the mass concentration of the aluminum salt solution is 5% -10% in terms of alumina, the amount of the aluminum salt solution is such that the physical pore-expanding agent is completely immersed, and the immersion time is 1-4 hours.

In the method, the alkaline solution in the step (1) can be a sodium hydroxide solution, ammonia water or a sodium metaaluminate solution, preferably the ammonia water, the mass concentration of the alkaline solution is 10-40%, the volume consumption of the alkaline solution is 10-20 times of the volume of the physical pore-expanding agent, and the impregnation time is 1-4 hours.

In the method, after the aluminum salt solution is absorbed by the physical pore-enlarging agent in the step (1), the physical pore-enlarging agent is dried and then absorbs the alkaline solution, wherein the drying conditions are as follows: drying at 100 ℃ and 140 ℃ for 1-4 hours.

In the method of the invention, the drying conditions in the step (1) are as follows: drying at 100 ℃ and 140 ℃ for 1-4 hours, wherein the roasting conditions are as follows: roasting at 400-500 ℃ for 3-6 hours, wherein the roasting is carried out under the protection of inert atmosphere, and the inert atmosphere is preferably nitrogen.

In the method of the present invention, the pseudoboehmite prepared in the step (2) can be a pseudoboehmite prepared by any method, for example, the pseudoboehmite is prepared by a precipitation method, an aluminum alkoxide hydrolysis method, an inorganic salt sol-gel method, a hydrothermal method, a vapor deposition method, etc., and the addition amount of the modified physical pore-enlarging agent is 10wt% to 20wt% of the weight of the intermediate.

In the method, the kneading molding in the step (2) is carried out by adopting a conventional method in the field, and a proper amount of conventional molding aids, such as one or more of peptizing agents, extrusion aids and the like, can be added according to needs in the molding process. The peptizing agent is one or more of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, oxalic acid and the like; the extrusion aid is sesbania powder.

In the method, the drying in the step (2) is drying at 100-140 ℃ for 1-4 hours, the roasting is roasting at 600-750 ℃ for 3-6 hours, and the roasting is carried out in an air atmosphere. The intermediate may be in the form of a conventional alumina support, such as a sphere, having a particle size of typically 0.5-8.0mm, such as a bar, clover, etc., having a diameter of about 0.2-3.0mm and a length of about 0.5-8.0 mm.

In the method, the mass ratio of the using amount of the ammonium bicarbonate solution in the step (3) to the added intermediate is 4:1-7:1, and the mass concentration of the ammonium bicarbonate solution is 15-25%.

In the method of the invention, the sealing heat treatment temperature in the step (3) is 120-.

In the method, the step (3) is preferably carried out before the sealing heat treatment, the sealing pretreatment is carried out, the pretreatment temperature is 60-100 ℃, the constant temperature treatment time is 2-4 hours, the temperature rise rate before the pretreatment is 10-20 ℃/min, the temperature rise rate after the pretreatment is 5-10 ℃/min, and the temperature rise rate after the pretreatment is at least 3 ℃/min lower than that before the pretreatment, preferably at least 5 ℃/min lower than that before the pretreatment.

In the method of the invention, the drying temperature in the step (3) is 160 ℃ plus 100 ℃, the drying time is 4-8 hours, the roasting temperature is 650 ℃ plus 550 ℃, and the roasting time is 4-6 hours.

In the method, the hydrogenation active component impregnation liquid in the step (4) is a solution containing VIB group and/or VIII group metals, wherein the VIB group metals are selected from one or more of W, Mo, the VIII group metals are selected from one or more of Co and Ni, the concentration of the VIB group metals is 8-17.5g/100mL calculated by metal oxides, the concentration of the VIII group metals is 2.5-5.0g/100mL calculated by metal oxides, and equal-volume impregnation or supersaturated impregnation can be adopted during impregnation. The drying temperature is 80-160 ℃, the drying time is 6-10 hours, and the roasting is 4-8 hours at the temperature of 450-550 ℃.

In another aspect of the present invention, there is provided a residual oil hydrodesulfurization catalyst prepared by the above method.

The hydrodesulfurization catalyst comprises a modified alumina-based carrier and a hydrogenation active metal component, wherein the modified alumina-based carrier comprises main modified alumina and rodlike modified alumina, the main modified alumina is modified alumina with micron-sized pore channels, and at least part of rodlike modified alumina is distributed on the outer surface of the main modified alumina and in the micron-sized pore channels with the pore diameter D of 3-7 mu m.

The micron-sized pore channels in the invention refer to micron-sized pore channels with the pore diameter of 3-7 μm.

The hydrogenation active metal component is VIB group and/or VIII group metal, the VIB group metal is selected from one or more of W, Mo, and the VIII group metal is selected from one or more of Co and Ni. Based on the weight of the hydrodesulfurization catalyst, the total content of the hydrogenation active metal components is 10% to 25%, preferably the content of the VIB group metal is 10% to 20% calculated by oxide, and the content of the VIII group metal is 3% to 10% calculated by oxide.

In the modified alumina-based carrier, the rodlike modified alumina is basically distributed on the outer surface of the main modified alumina and in the micron-sized pore channels. The rod-shaped modified alumina distributed on the outer surface of the main body modified alumina and in the micron-sized pore channels accounts for more than 95 percent of the total weight of all the rod-shaped modified aluminas, and preferably more than 97 percent.

In the modified alumina-based carrier, the length of the rod-shaped modified alumina in the micron-sized pore channel is mainly 0.3D-0.9D (which is 0.3-0.9 time of the diameter of the micron-sized pore channel), namely the length of more than 85 percent of the rod-shaped modified alumina in the micropore is 0.3D-0.9D by weight; the length of the rod-shaped modified alumina on the outer surface is mainly 3-8 μm, namely, the length of more than 85 percent of the rod-shaped modified alumina on the outer surface is 3-8 μm.

The diameter of the rod-shaped modified alumina is 80-260 nm.

In the modified alumina-based carrier, rod-shaped modified alumina is distributed in a disordered and mutually staggered state in micron-sized pore channels of main modified alumina.

In the modified alumina-based carrier of the present invention, at least one end of at least a part of the rod-shaped modified alumina is attached to the micron-sized pore wall of the main body modified alumina, and preferably, at least one end of at least a part of the rod-shaped modified alumina is bonded to the micron-sized pore wall to be integrated with the main body modified alumina. Further preferably, at least one end of the rod-like modified alumina in the micron-sized pore channel is bonded to the wall of the micron-sized pore channel, and is integrated with the main body of the modified alumina.

In the modified alumina-based carrier of the present invention, rod-like modified aluminas are distributed in a disordered and mutually staggered state on the outer surface of the main body modified alumina.

In the modified alumina-based carrier of the present invention, one end of at least a part of the rod-shaped modified alumina is attached to the outer surface of the main modified alumina, and preferably, one end of at least a part of the rod-shaped modified alumina is bonded to the outer surface of the main modified alumina, and the other end thereof protrudes outward and is integrated with the main modified alumina. Further preferably, one end of the rod-shaped modified alumina on the outer surface of the body modified alumina is bonded to the outer surface of the body modified alumina, and the other end thereof protrudes outward and is integrated with the body.

In the modified alumina-based carrier, the coverage rate of the rod-shaped modified alumina in the micron-sized pore canal of the main body modified alumina is 75-95%, wherein the coverage rate refers to the percentage of the surface of the inner surface of the micron-sized pore canal of the main body modified alumina, which is occupied by the rod-shaped modified alumina, in the inner surface of the micron-sized pore canal of the main body modified alumina. The coverage rate of the rod-shaped modified alumina on the outer surface of the main body modified alumina is 70-95%, wherein the coverage rate refers to the percentage of the surface occupied by the rod-shaped modified alumina on the outer surface of the main body modified alumina.

The hydrodesulfurization catalyst prepared by the invention has the following properties: the specific surface area is 220-320m²(iv)/g, pore volume of 0.8-1.8mL/g, crush strength of 15-22N/mm.

In the hydrodesulfurization catalyst prepared by the invention, the pores formed by the rod-shaped modified alumina in a disordered and staggered manner are concentrated between 100 and 600 nm.

The pore distribution of the hydrodesulfurization catalyst prepared by the invention is as follows: the pore volume of the pores with the pore diameter of less than 10nm is less than 20 percent of the total pore volume, the pore volume of the pores with the pore diameter of 10-30nm is 40-60 percent of the total pore volume, the pore volume of the pores with the pore diameter of 100-600nm is 12-25 percent of the total pore volume, and the pore volume of the pores with the pore diameter of more than 1000nm is less than 5 percent.

The hydrodesulfurization catalyst is suitable for a residual oil hydrodesulfurization treatment process, and has high desulfurization rate and high hydrogenation carbon residue removal rate.

Compared with the prior art, the invention has the following advantages:

1. in the process of preparing the hydrodesulfurization catalyst, the physical pore-enlarging agent is sequentially attached to an aluminum salt solution and an alkaline solution, aluminum ions form precipitates with uniform particle sizes, and alumina is formed and attached to the physical pore-enlarging agent during roasting in an inert atmosphere. When the carrier is roasted after being formed, alumina in the physical pore-enlarging agent is anchored in the micron-sized pore channel, and when the alumina carrier is subjected to sealed hydrothermal treatment in an ammonium bicarbonate solution system, alumina in the micron-sized pore channel grows secondarily to form alumina in a rod-shaped structure.

2. In the process of preparing the hydrodesulfurization catalyst, the intermediate is pretreated at a certain temperature before sealing heat treatment, the conditions during pretreatment are relatively mild, and the intermediate slowly forms NH under the sealing, hydrothermal and mixed atmosphere of carbon dioxide and ammonia gas₄Al(OH)₂CO₃Crystal nuclei, raising the reaction temperature NH during the post-heat treatment₄Al(OH)₂CO₃The crystal nucleus continues to grow evenly to make rod-shaped NH₄Al(OH)₂CO₃Having uniform diameter and length while increasing rod-like NH₄Al(OH)₂CO₃Coverage on the outer surface of the intermediate body and the inner surface of the micron-sized pore channel.

3. The hydrodesulfurization catalyst fully utilizes the micron-sized pore channels of the intermediate, and the rod-shaped modified alumina is distributed in the micron-sized pore channels in a staggered mode in a random mode, so that on one hand, the penetrability of the micron-sized pore channels is maintained, the specific surface area of the catalyst is improved, the mechanical strength is enhanced, on the other hand, gas generated by combustion of a physical pore-expanding agent plays a certain hole-expanding role in the intermediate nanoscale pore channels, the penetrability and the uniformity of the nanoscale pore channels are further promoted, and the diffusion performance of macromolecular reactants is improved.

Drawings

FIG. 1 is an SEM photograph of a modified alumina-based support obtained in example 1;

wherein the reference numbers are as follows: 1-main body modified alumina, 2-rod-shaped modified alumina and 3-micron pore canal.

Detailed Description

The following examples are provided to further illustrate the technical solutions of the present invention, but the present invention is not limited to the following examples. In the present invention, wt% is a mass fraction and v% is a volume fraction.

Application N₂Physical adsorption-desorption characterization of the pore structures of the carriers and catalysts of the examples and the comparative examples, the specific operations are as follows: adopting ASAP-2420 type N₂And the physical adsorption-desorption instrument is used for characterizing the pore structure of the sample. A small amount of samples are taken to be treated for 3 to 4 hours in vacuum at the temperature of 300 ℃, and finally, the product is placed under the condition of liquid nitrogen low temperature (-200 ℃) to be subjected to nitrogen absorption-desorption test. Wherein the specific surface area is obtained according to a BET equation, and the distribution rate of the pore volume and the pore diameter below 40nm is obtained according to a BJH model.

Mercury pressing method: the pore diameter distribution of the carrier of the catalyst and the example and the comparative example are characterized by using a mercury porosimeter, and the specific operation is as follows: and characterizing the distribution of sample holes by using an American microphone AutoPore9500 full-automatic mercury porosimeter. The samples were dried, weighed into an dilatometer, degassed for 30 minutes while maintaining the vacuum conditions given by the instrument, and filled with mercury. The dilatometer was then placed in the autoclave and vented. And then carrying out a voltage boosting and reducing test. The mercury contact angle is 130 degrees, and the mercury interfacial tension is 0.485N.cm^-1The distribution ratio of pore diameter of 100nm or more is measured by mercury intrusion method.

A scanning electron microscope is used for representing the microstructure of the alumina carrier, and the specific operation is as follows: and a JSM-7500F scanning electron microscope is adopted to represent the microstructure of the carrier, the accelerating voltage is 5KV, the accelerating current is 20 muA, and the working distance is 8 mm.