A catalyst suitable for catalytic deoxygenation to produce high-purity hydrogen in the hydrogen production industry and its preparation method

Abstract

A catalyst suitable for catalytic deoxidation to produce high-purity hydrogen in the hydrogen production industry and a preparation method thereof belong to the field of catalyst technology. The preparation method of the catalyst suitable for catalytic deoxidation to produce high-purity hydrogen in the hydrogen production industry comprises five steps: preparing a slurry, forming, hydrolysis and solidification, oxidative roasting, and hydrogen reduction. The catalyst suitable for catalytic deoxidation to produce high-purity hydrogen in the hydrogen production industry obtained by the present invention has catalytic deoxidation performance, can reduce the outlet oxygen volume concentration to 1.47-2.54 ppm, and has a crushing strength of 125-130 N·cm ‑1 , the wear rate is 0.5~0.9%.

Description

Technical Field

[0001] The present invention relates to a catalyst suitable for catalytic deoxidation to prepare high-purity hydrogen in the hydrogen production industry and a preparation method thereof, belonging to the technical field of catalysts. Background Art

[0002] Hydrogen is a high-energy-density, zero-carbon renewable energy source that can be used as a power source for fuel cells. Hydrogen production by water electrolysis is a common industrial process, but the resulting hydrogen is often inevitably doped with 0.3–0.6% (volume percentage) of oxygen. In the fuel cell industry, trace amounts of oxygen in hydrogen can lead to low efficiency and poor stability during operation. According to ISO 14687:2019, published in 2019 by the ISO Technical Committee on Hydrogen, the oxygen content of hydrogen used in fuel cells must be limited to less than 5 μL / L. Furthermore, in the industrial hydrogen sector, trace amounts of oxygen in hydrogen not only reduce the quality and yield of the target product, but also shorten the life of production equipment and process stability, posing a significant safety hazard. Deep deoxygenation of hydrogen has become a critical technical issue that urgently needs to be addressed.

[0003] Existing methods for hydrogen deoxygenation include physical and chemical methods. Physical methods are generally physical adsorption, while chemical methods include chemical absorption and catalytic deoxygenation. Catalytic deoxygenation has the advantages of wide application, high safety, and simple operation, making it the most widely used method for hydrogen deoxygenation.

[0004] During the deoxygenation of hydrogen using the catalytic deoxygenation method, part of the hydrogen acts as a sacrificial agent and reacts with oxygen under the catalytic action of the deoxygenation catalyst to generate water, which is then separated and removed. The use of the deoxygenation catalyst can effectively reduce the energy barrier of the deoxygenation reaction, making hydrogen deoxygenation more economical and efficient. Existing deoxygenation catalysts generally use silica, alumina, etc. as carriers, and precious metal catalysts such as platinum and palladium as the main active components. Although precious metal catalysts can achieve good hydrogen deoxygenation effects, the precious metal resources they use are scarce, expensive, and the cost of industrial application is high, which directly limits their large-scale industrial application. At the same time, the long-term catalytic stability of precious metal deoxygenation catalysts needs to be further improved.

[0005] Existing deoxidation catalysts use non-precious metals such as transition metals as active ingredients. Although their active ingredients are easier to obtain than precious metals, non-precious metal deoxidation catalysts have poor low-temperature catalytic activity and catalytic efficiency, and can only achieve good deoxidation catalytic performance under high-temperature conditions. At the same time, non-precious metal deoxidation catalysts have poor selectivity and are prone to side reactions during the hydrogen deoxidation process, which directly leads to hydrogen loss. In addition, non-precious metal deoxidation catalysts are unstable and are easily affected by high-temperature environments and other impurities in hydrogen, resulting in a short long-term service life.

[0006] Chinese patent CN104001507A discloses a deoxidation catalyst and its preparation method. It uses a cordierite ceramic honeycomb as a carrier, an Al2O3, CeO2, and ZrO2 composite material as a catalyst transition layer, and Pt, Pd, and Rh as the catalyst's active components. The Pt, Pd, and Rh contents per liter of the catalyst are 0.05-0.2 grams, 0.5-1.5 grams, and 0.05-0.2 grams, respectively. The Al2O3, CeO2, and ZrO2 contents are 15-75 grams, 3-15 grams, and 3-15 grams, respectively. The preparation method involves pretreating the cordierite ceramic honeycomb carrier, then coating the catalyst transition layer with the Al2O3, CeO2, and ZrO2 composite material by an impregnation method, and then loading the Pt, Pd, and Rh active components by a precipitation-adsorption method. Although the deoxygenation catalyst obtained by this patent can effectively remove oxygen from hydrogen, it uses expensive precious metals palladium and platinum and is not particularly suitable for large-scale industrial applications.

[0007] Chinese patent CN103071488A discloses a catalyst for the catalytic deoxidation of hydrogen to produce high-purity hydrogen, as well as its preparation method and application. The catalyst comprises palladium or platinum as the primary active component, with a small amount of rare earth elements and transition metals added as co-catalysts. The catalyst is prepared by impregnation, drying, and calcination with a catalyst support. The catalyst prepared in this patent uses palladium or platinum as the primary active component. While the addition of a small amount of rare earth elements and transition metals as co-catalysts reduces the amount of precious metals, the use of precious metals is not completely avoided. Furthermore, the deoxidation operating temperature is above 100°C, indicating poor catalytic activity at low temperatures.

[0008] Thus, a non-precious metal deoxidation catalyst is provided, which can simultaneously improve its low-temperature catalytic activity and catalytic efficiency, reduce the required catalytic temperature, and at the same time improve the hydrogen deoxidation selectivity of the non-precious metal deoxidation catalyst, avoid the occurrence of side reactions during the hydrogen deoxidation process, and further improve the stability of the non-precious metal deoxidation catalyst, thereby increasing its long-term service life, which has important technical significance and research value. Summary of the Invention

[0009] In view of the deficiencies in the above-mentioned prior art, the present invention provides a catalyst and a preparation method thereof suitable for catalytic deoxygenation to produce high-purity hydrogen in the hydrogen production industry, to achieve the following invention objectives: to prepare a non-precious metal deoxygenation catalyst with high low-temperature catalytic activity, good selectivity and long service life, which is suitable for deoxygenation to produce high-purity hydrogen in the hydrogen production industry.

[0010] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0011] A catalyst suitable for catalytic deoxygenation to produce high-purity hydrogen in the hydrogen production industry and a preparation method thereof. The catalyst suitable for catalytic deoxygenation to produce high-purity hydrogen in the hydrogen production industry has a catalytic deoxygenation performance that can reduce the outlet oxygen volume concentration to 1.47-2.54 ppm and a crushing strength of 125-130 N·cm -1 , the wear rate is 0.5~0.9%;

[0012] The preparation method of the catalyst suitable for catalytic deoxidation to produce high-purity hydrogen in the hydrogen production industry includes five steps: preparing slurry, forming, hydrolysis and solidification, oxidative roasting, and hydrogen reduction;

[0013] The following are further improvements to the above technical solution:

[0014] Step 1: Prepare slurry

[0015] Put anhydrous acetone, organic polysilazane, molybdenum acetylacetonate, cobalt acetylacetonate, magnesium acetylacetonate, and nano zirconium phosphate into a double planetary mixer, stir and disperse at high speed, add rosin and petroleum resin after the nano zirconium phosphate is evenly dispersed, continue stirring and dispersing until the nano zirconium phosphate is evenly dispersed, and then discharge the material to obtain a paste slurry;

[0016] The organopolysilazane has a number average molecular weight of 800 to 1300 g / mol and a viscosity of 10 to 50 mPa·s at 25° C.;

[0017] The particle size of the nano zirconium phosphate is 10-100 nm;

[0018] The mass ratio of the anhydrous acetone, organopolysilazane, molybdenum acetylacetonate, cobalt acetylacetonate, magnesium acetylacetonate, nano zirconium phosphate, rosin, and petroleum resin is 40-90:40-90:5-9:2-5:0.3-4:8-15:9-20:10-30;

[0019] The high-speed stirring and dispersing process has a stirring rate of 90 to 130 rpm and a dispersion rate of 8,000 to 14,000 rpm;

[0020] The nano zirconium phosphate is uniformly dispersed, and the average particle size of the nano zirconium phosphate in the double planetary mixer is less than 0.6-1 μm;

[0021] The stirring and dispersion are continued to be uniform, and the stirring and dispersion time is 5 to 9 hours.

[0022] Step 2: Molding

[0023] The paste slurry is injected into the extruder, and the extruder screw speed and the diameter of the die head are adjusted to extrude long strip particles. The cross-sectional diameter of the particles is controlled to be 1~5mm and the length is 6~13mm to obtain the catalyst original particles.

[0024] Step 3: Hydrolysis and curing

[0025] The catalyst original particles are placed in an oven with a relative air humidity of 70-85% and a temperature of 75-95° C., and hydrolyzed and cured at constant temperature and humidity for 13-20 hours to obtain cured catalyst particles.

[0026] Step 4: Oxidation roasting

[0027] The solidified catalyst particles are placed in a muffle furnace, heated to 550-700°C at a rate of 1-3°C / min, and calcined at a constant temperature for 6-11 hours to obtain oxidatively calcined catalyst particles.

[0028] Step 5: Hydrogen reduction

[0029] The catalyst particles after oxidation roasting are placed in a reduction furnace, and under the condition of continuous hydrogen flow, the temperature is raised to 350-500°C at a rate of 2-5°C / min, and the temperature is reduced at a constant temperature for 5-10 hours. Then, under the protection of hydrogen, the temperature is lowered to room temperature. After the hydrogen is replaced with nitrogen, the catalyst suitable for catalytic deoxygenation to prepare high-purity hydrogen in the hydrogen production industry is obtained.

[0030] Compared with the prior art, the present invention achieves the following beneficial effects:

[0031] 1. The present invention utilizes the property that liquid organopolysilazane can be hydrolyzed, cross-linked, and cured at room temperature and oxidized and calcined at high temperature to form ceramics. First, in an anhydrous acetone solvent system, the organopolysilazane and three types of metal salts, namely acetylacetonate, cobalt acetylacetonate, and magnesium acetylacetonate, which are easily hydrolyzed to form metal salts, and nano zirconium phosphate are fully mixed, and then rosin and petroleum resin are added as thickeners and binders to assist in molding. After being molded into catalyst particles, in the hydrolysis and curing step, the liquid organopolysilazane undergoes hydrolysis, cross-linking, and curing reactions in a high temperature and high humidity environment. The molybdenum acetylacetonate, cobalt acetylacetonate, and magnesium acetylacetonate also undergo hydrolysis or decomposition reactions in the high temperature and high humidity environment to generate corresponding metal salts or metal oxides. The molybdenum, cobalt, and magnesium formed The metal salt or metal oxide will be adsorbed inside or on the surface of the cross-linked network skeleton formed by the organic polysilazane through the action of electric charge. Secondly, the nano-zirconium phosphate will also adsorb the molybdenum-cobalt-magnesium metal salt or molybdenum-cobalt-magnesium metal oxide. In this way, in the subsequent oxidation roasting step, the cross-linked network formed by the hydrolysis of the organic polysilazane and the carbon elements remaining from the petroleum resin and rosin ablation will be sintered into SiCN ceramics at high temperature. The nano-zirconium phosphate and the molybdenum-cobalt-magnesium metal salt or molybdenum-cobalt-magnesium metal oxide will be sintered together in the SiCN ceramic skeleton or on the skeleton surface. Moreover, after a long period of oxidation roasting, the molybdenum-cobalt-magnesium will eventually exist in the form of metal oxides. After hydrogen reduction, the corresponding metal elements will be formed, which will have very excellent deoxidation catalytic performance.

[0032] 2. The present invention adds molybdenum acetylacetonate, cobalt acetylacetonate, and magnesium acetylacetonate. First, by utilizing the acetone solubility of these three substances, the three substances are uniformly dispersed in the liquid organopolysilazane through a strong shear dispersion process. Then, by utilizing the easy hydrolysis or decomposition properties of these three organometallic compounds, and in the process of simultaneous hydrolysis reaction of the liquid organopolysilazane, the three metal elements of molybdenum, cobalt, and magnesium are uniformly dispersed in the cross-linked network formed by the organopolysilazane. In this way, after oxidative roasting and hydrogen reduction, the three metal elements of molybdenum, cobalt, and magnesium can exist in the deoxidation catalyst matrix as very uniform and fine particles. Moreover, the three metal elements of molybdenum, cobalt, and magnesium have a very good synergistic effect in terms of deoxidation catalytic performance, thereby significantly improving the low-temperature deoxidation performance of the final catalyst.

[0033] 3. The nano-zirconium phosphate added in the present invention enhances the concentration of catalytically active substances in the catalyst by adsorbing and sintering the oxides of magnesium, cobalt, and molybdenum. Furthermore, the relatively large specific surface area of ​​the nano-zirconium phosphate provides a larger reaction site for catalytic deoxidation. Furthermore, the nano-zirconium phosphate itself may also have certain deoxidation catalytic properties, which further increases the deoxidation catalytic activity of the catalyst obtained in the present invention. Furthermore, during the oxidative roasting process, the nano-zirconium phosphate can sinter together with the oxides of magnesium, cobalt, and molybdenum and the hydrolyzate of the organopolysilazane, thereby increasing the density of the sintered catalyst and enhancing the overall mechanical properties of the catalyst.

[0034] 4. The catalyst obtained by the present invention is suitable for catalytic deoxygenation to produce high-purity hydrogen in the hydrogen production industry. In terms of catalytic deoxygenation performance, the outlet oxygen volume concentration can be reduced to 1.47~2.54ppm, and the crushing strength is 125~130N·cm -1 , the wear rate is 0.5~0.9%. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a scanning electron microscope photograph of the cross section of the catalyst obtained in Example 1, which is suitable for catalytic deoxidation to produce high-purity hydrogen in the hydrogen production industry;

[0036] Figure 2 This is a scanning electron microscope photograph of the cross section of the catalyst obtained in Comparative Example 4, which is suitable for catalytic deoxidation to produce high-purity hydrogen in the hydrogen production industry, magnified 10,000 times. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present invention are described below. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0038] Example 1: A method for preparing a catalyst suitable for catalytic deoxygenation to produce high-purity hydrogen in the hydrogen production industry

[0039] Step 1: Prepare slurry

[0040] Put anhydrous acetone, organic polysilazane, molybdenum acetylacetonate, cobalt acetylacetonate, magnesium acetylacetonate, and nano zirconium phosphate into a double planetary mixer, stir and disperse at high speed, add rosin and petroleum resin after the nano zirconium phosphate is evenly dispersed, continue stirring and dispersing until the nano zirconium phosphate is evenly dispersed, and then discharge the material to obtain a paste slurry;

[0041] The organopolysilazane has a number average molecular weight of 1100 g / mol and a viscosity of 40 mPa·s at 25° C.;

[0042] The particle size of the nano zirconium phosphate is 30 nm;

[0043] The mass ratio of the anhydrous acetone, organopolysilazane, molybdenum acetylacetonate, cobalt acetylacetonate, magnesium acetylacetonate, nano zirconium phosphate, rosin, and petroleum resin is 60:70:8:4:2:11:13:19;

[0044] The high-speed stirring and dispersing process has a stirring rate of 120 rpm and a dispersion rate of 13,000 rpm;

[0045] The nano zirconium phosphate is uniformly dispersed, and the average particle size of the nano zirconium phosphate in the double planetary mixer is less than 0.7 μm;

[0046] The stirring and dispersion were continued to be uniform, and the stirring and dispersion time was 8 hours.

[0047] Step 2: Molding

[0048] The paste slurry was injected into the extruder, and the screw speed of the extruder and the diameter of the die of the die head were adjusted to extrude long strip particles. The cross-sectional diameter of the particles was controlled to be 2 mm and the length was 11 mm to obtain the catalyst original particles.

[0049] Step 3: Hydrolysis and curing

[0050] The original catalyst particles were placed in an oven at a relative humidity of 80% and a temperature of 90° C., and hydrolyzed and cured at constant temperature and humidity for 16 hours to obtain cured catalyst particles.

[0051] Step 4: Oxidation roasting

[0052] The solidified catalyst particles were placed in a muffle furnace, heated to 650° C. at a rate of 2° C. / min, and calcined at a constant temperature for 9 hours to obtain oxidatively calcined catalyst particles.

[0053] Step 5: Hydrogen reduction

[0054] The catalyst particles after oxidation roasting are placed in a reduction furnace, and under the condition of continuous hydrogen flow, the temperature is raised to 450°C at a rate of 4°C / min, and reduced at a constant temperature for 8 hours. Then, under the protection of hydrogen, the temperature is cooled to room temperature. After replacing the hydrogen with nitrogen, the catalyst suitable for catalytic deoxidation to produce high-purity hydrogen in the hydrogen production industry is obtained.

[0055] Example 2: A method for preparing a catalyst suitable for catalytic deoxygenation to produce high-purity hydrogen in the hydrogen production industry

[0056] Step 1: Prepare slurry

[0057] Put anhydrous acetone, organic polysilazane, molybdenum acetylacetonate, cobalt acetylacetonate, magnesium acetylacetonate, and nano zirconium phosphate into a double planetary mixer, stir and disperse at high speed, add rosin and petroleum resin after the nano zirconium phosphate is evenly dispersed, continue stirring and dispersing until the nano zirconium phosphate is evenly dispersed, and then discharge the material to obtain a paste slurry;

[0058] The organopolysilazane has a number average molecular weight of 800 g / mol and a viscosity of 10 mPa·s at 25° C.;

[0059] The particle size of the nano zirconium phosphate is 10 nm;

[0060] The mass ratio of the anhydrous acetone, organopolysilazane, molybdenum acetylacetonate, cobalt acetylacetonate, magnesium acetylacetonate, nano zirconium phosphate, rosin, and petroleum resin is 40:40:5:2:0.3:8:9:10;

[0061] The high-speed stirring and dispersing process has a stirring rate of 90 rpm and a dispersion rate of 8000 rpm;

[0062] The nano zirconium phosphate is uniformly dispersed, and the average particle size of the nano zirconium phosphate in the double planetary mixer is less than 0.6 μm;

[0063] The stirring and dispersion were continued to be uniform, and the stirring and dispersion time was 5 hours.

[0064] Step 2: Molding

[0065] The paste slurry was injected into the extruder, and the screw speed of the extruder and the diameter of the die of the die head were adjusted to extrude long strip particles. The cross-sectional diameter of the particles was controlled to be 1 mm and the length was 6 mm to obtain the catalyst original particles.

[0066] Step 3: Hydrolysis and curing

[0067] The catalyst original particles were placed in an oven at a relative humidity of 70% and a temperature of 75° C., and hydrolyzed and cured at constant temperature and humidity for 13 hours to obtain cured catalyst particles.

[0068] Step 4: Oxidation roasting

[0069] The solidified catalyst particles were placed in a muffle furnace, heated to 550° C. at a rate of 1° C. / min, and calcined at a constant temperature for 6 hours to obtain oxidatively calcined catalyst particles.

[0070] Step 5: Hydrogen reduction

[0071] The catalyst particles after oxidation roasting were placed in a reduction furnace, and under the condition of continuous hydrogen flow, the temperature was raised to 350°C at a rate of 2°C / min, and reduced at a constant temperature for 5 hours. Then, under the protection of hydrogen, the temperature was lowered to room temperature. After replacing the hydrogen with nitrogen, the catalyst suitable for catalytic deoxidation to produce high-purity hydrogen in the hydrogen production industry was obtained.

[0072] Example 3: A method for preparing a catalyst suitable for catalytic deoxygenation to produce high-purity hydrogen in the hydrogen production industry

[0073] Step 1: Prepare slurry

[0074] Put anhydrous acetone, organic polysilazane, molybdenum acetylacetonate, cobalt acetylacetonate, magnesium acetylacetonate, and nano zirconium phosphate into a double planetary mixer, stir and disperse at high speed, add rosin and petroleum resin after the nano zirconium phosphate is evenly dispersed, continue stirring and dispersing until the nano zirconium phosphate is evenly dispersed, and then discharge the material to obtain a paste slurry;

[0075] The organopolysilazane has a number average molecular weight of 1300 g / mol and a viscosity of 50 mPa·s at 25° C.;

[0076] The particle size of the nano zirconium phosphate is 100 nm;

[0077] The mass ratio of the anhydrous acetone, organopolysilazane, molybdenum acetylacetonate, cobalt acetylacetonate, magnesium acetylacetonate, nano zirconium phosphate, rosin, and petroleum resin is 90:90:9:5:4:15:20:30;

[0078] The high-speed stirring and dispersing process has a stirring rate of 130 rpm and a dispersion rate of 14,000 rpm;

[0079] The nano zirconium phosphate is uniformly dispersed, and the average particle size of the nano zirconium phosphate in the double planetary mixer is less than 1 μm;

[0080] The stirring and dispersion were continued to be uniform, and the stirring and dispersion time was 9 hours.

[0081] Step 2: Molding

[0082] The paste slurry was injected into the extruder, and the screw speed of the extruder and the diameter of the die of the die head were adjusted to extrude long strip particles. The cross-sectional diameter of the particles was controlled to be 5 mm and the length was 13 mm to obtain the catalyst original particles.

[0083] Step 3: Hydrolysis and curing

[0084] The catalyst original particles were placed in an oven at a relative humidity of 85% and a temperature of 95° C., and hydrolyzed and cured at constant temperature and humidity for 20 hours to obtain cured catalyst particles.

[0085] Step 4: Oxidation roasting

[0086] The solidified catalyst particles were placed in a muffle furnace, heated to 700° C. at a rate of 3° C. / min, and calcined at a constant temperature for 11 hours to obtain oxidatively calcined catalyst particles.

[0087] Step 5: Hydrogen reduction

[0088] The catalyst particles after oxidation roasting were placed in a reduction furnace, and under the condition of continuous hydrogen flow, the temperature was raised to 500°C at a rate of 5°C / min, and reduced at a constant temperature for 10 hours. Then, under the protection of hydrogen, the temperature was lowered to room temperature. After the hydrogen was replaced with nitrogen, the catalyst suitable for catalytic deoxygenation to produce high-purity hydrogen in the hydrogen production industry was obtained.

[0089] Comparative Example 1: Based on Example 1, in step 1, in preparing the slurry, 2 parts of magnesium acetylacetonate were replaced with 2 parts of organopolysilazane. The specific operation was as follows:

[0090] Step 1: Prepare slurry

[0091] The remaining steps were the same as in Example 1 except that 2 parts of magnesium acetylacetonate were replaced by 2 parts of organopolysilazane.

[0092] The operations of steps 2, 3, 4, and 5 are the same as those in Example 1.

[0093] Comparative Example 2: Based on Example 1, in step 1, in preparing the slurry, 8 parts of molybdenum acetylacetonate were replaced with 8 parts of organopolysilazane. The specific operation was as follows:

[0094] Step 1: Prepare slurry

[0095] 8 parts of molybdenum acetylacetonate were replaced by 8 parts of organopolysilazane, and the other operations were the same as in Example 1;

[0096] The operations of steps 2, 3, 4, and 5 are the same as those in Example 1.

[0097] Comparative Example 3: Based on Example 1, in step 1, in preparing the slurry, 4 parts of cobalt acetylacetonate were replaced with 4 parts of organopolysilazane. The specific operation was as follows:

[0098] Step 1: Prepare slurry

[0099] The remaining steps were the same as in Example 1 except that 2 parts of magnesium acetylacetonate were replaced by 2 parts of organopolysilazane.

[0100] The operations of steps 2, 3, 4, and 5 are the same as those in Example 1.

[0101] Comparative Example 4: Based on Example 1, in step 1, in preparing the slurry, no nano zirconium phosphate was added, and 11 parts of nano zirconium phosphate were replaced with 11 parts of organopolysilazane. The specific operation was as follows:

[0102] Step 1: Prepare slurry

[0103] The 11 parts of nano-zirconium phosphate were replaced by 11 parts of organopolysilazane, and the other operations were the same as in Example 1;

[0104] The operations of steps 2, 3, 4, and 5 are the same as those in Example 1.

[0105] Performance testing:

[0106] The catalysts suitable for catalytic deoxidation to prepare high-purity hydrogen in the hydrogen production industry obtained in Examples 1, 2, 3 and Comparative Examples 1, 2, 3, and 4 were loaded into a fixed-bed reactor with a diameter of φ20 mm×400 mm (diameter×length) and heated at 50°C, atmospheric pressure, and a gas space velocity of 15000 h -1 The deoxidation performance was tested under the following conditions: the composition of the feed gas was 8000-12000ppm by volume of oxygen, 2000-3000ppm by volume of water, and the remainder was hydrogen. In addition, the crushing strength was tested according to "HG / T 2782-2011 Determination of the Crush Resistance of Fertilizer Catalyst Granules", and the attrition rate was tested according to "HG / T 2976-2011 Determination of the Attrition Rate of Fertilizer Catalysts".

[0107] The test results are shown in Table 1:

[0108] Table 1

[0109]

[0110] From the test data in Table 1, it can be seen that the outlet oxygen volume concentration of Examples 1-3 is all below 3 ppm, and the crushing strength is 120 N·cm -1 The above, the attrition rate is less than 1%, which shows that the catalyst obtained by the present invention is suitable for catalytic deoxidation to prepare high-purity hydrogen in the hydrogen production industry, and has the advantages of high low-temperature catalytic activity, good selectivity and excellent mechanical properties, long service life, etc.; in Comparative Examples 1, 2 and 3, magnesium acetylacetonate, molybdenum acetylacetonate and cobalt acetylacetonate were not added respectively, and the outlet oxygen volume concentration of these three comparative examples increased significantly, and the deoxidation catalytic activity was greatly reduced, especially in Comparative Example 2 where molybdenum acetylacetonate was not added, the outlet oxygen volume concentration was the highest, which shows that the molybdenum element plays the role of the main catalyst, and the cobalt and magnesium elements play a synergistic role in promoting the catalysis. In addition, the crushing strength and attrition rate of Comparative Examples 1, 2 and 3 are no different from those of Example 1, which shows that after magnesium acetylacetonate, molybdenum acetylacetonate and cobalt acetylacetonate are hydrolyzed to produce oxides of magnesium, cobalt and molybdenum elements, , does not affect the overall mechanical properties of the catalyst; Comparative Example 4 does not add nano-zirconium phosphate, the outlet oxygen volume concentration of Comparative Example 4 rises to the highest, and the deoxidation catalytic activity drops to the worst state among all the embodiments and comparative examples, which indicates that nano-zirconium phosphate may enhance the concentration of catalytically active substances in the catalyst by adsorbing and sintering magnesium, cobalt, and molybdenum oxides, and nano-zirconium phosphate has a relatively large specific surface area, which also provides a larger reaction site for catalytic deoxidation. At the same time, nano-zirconium phosphate itself may also have certain deoxidation catalytic properties. In addition, the crushing strength of Comparative Example 4 is greatly reduced, and the attrition rate is greatly increased, which indicates that nano-zirconium phosphate can be sintered with magnesium, cobalt, and molybdenum oxides and the hydrolyzate of organic polysilazane during the oxidative roasting process, thereby improving the density of the catalyst after sintering and enhancing the overall mechanical properties of the catalyst.

[0111] Attachment Figure 1 and attached Figure 2 The catalysts obtained in Example 1 and Comparative Example 4 are suitable for catalytic deoxidation to prepare high-purity hydrogen in the hydrogen production industry, and the scanning electron microscope photos of their cross sections magnified 10,000 times are attached. Figure 1 It is clear that tiny particles scattered on the cross section are formed by the adsorption and sintering of nano zirconium phosphate on the surface of SiCN ceramic skeleton. Figure 2 There are no scattered tiny particles in the image, only skeleton particles connected to each other can be seen, and under the same magnification, the attached Figure 1 The density is much greater than that of the Figure 2This shows that nano zirconium phosphate can improve the sintering density, thereby giving the catalyst excellent mechanical properties and long service life.

[0112] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a catalyst suitable for catalytic deoxidation to produce high-purity hydrogen in the hydrogen production industry, characterized by: The preparation method of the catalyst suitable for catalytic deoxidation to prepare high-purity hydrogen in the hydrogen production industry includes five steps: preparing slurry, forming, hydrolysis and solidification, oxidative roasting, and hydrogen reduction; The slurry is prepared by placing anhydrous acetone, organic polysilazane, molybdenum acetylacetonate, cobalt acetylacetonate, magnesium acetylacetonate, and nano zirconium phosphate into a double planetary mixer, stirring and dispersing at high speed, and adding rosin and petroleum resin after the nano zirconium phosphate is evenly dispersed. After continuing to stir and disperse evenly, the material is discharged to obtain a paste slurry; The organopolysilazane has a number average molecular weight of 800 to 1300 g / mol and a viscosity of 10 to 50 mPa·s at 25° C.; The particle size of the nano zirconium phosphate is 10-100 nm; The hydrolysis and curing step is to place the catalyst particles obtained after forming in an oven with a relative humidity of 70-85% and a temperature of 75-95°C, and perform hydrolysis and curing at a constant temperature and humidity for 13-20 hours to obtain cured catalyst particles; The oxidative calcination is to place the solidified catalyst particles in a muffle furnace, raise the temperature to 550-700° C. at a rate of 1-3° C. / min, and calcine at a constant temperature for 6-11 hours to obtain oxidatively calcined catalyst particles.

2. The method for preparing a catalyst for catalytic deoxidation to produce high-purity hydrogen in the hydrogen production industry according to claim 1, characterized in that: The mass ratio of the anhydrous acetone, organopolysilazane, molybdenum acetylacetonate, cobalt acetylacetonate, magnesium acetylacetonate, nano zirconium phosphate, rosin, and petroleum resin is 40-90:40-90:5-9:2-5:0.3-4:8-15:9-20:10-30; The high-speed stirring and dispersing process has a stirring rate of 90 to 130 rpm and a dispersion rate of 8,000 to 14,000 rpm; The nano zirconium phosphate is uniformly dispersed, and the average particle size of the nano zirconium phosphate in the double planetary mixer is less than 0.6-1 μm; The stirring and dispersion are continued to be uniform, and the stirring and dispersion time is 5 to 9 hours.

3. The method for preparing a catalyst for catalytic deoxidation to produce high-purity hydrogen in the hydrogen production industry according to claim 1, characterized in that: The forming process includes injecting the paste slurry into an extruder, adjusting the extruder screw speed and the diameter of the die head, extruding long strip particles, and controlling the cross-sectional diameter of the particles to be 1-5 mm and the length to be 6-13 mm to obtain catalyst original particles.

4. The method for preparing a catalyst for catalytic deoxidation to produce high-purity hydrogen in the hydrogen production industry according to claim 1, characterized in that: The hydrogen reduction comprises placing the oxidatively calcined catalyst particles into a reduction furnace, continuously introducing hydrogen, raising the temperature to 350-500°C at a rate of 2-5°C / min, and reducing the particles at a constant temperature for 5-10 hours. The particles are then cooled to room temperature under hydrogen protection, and the hydrogen is replaced with nitrogen to obtain a catalyst suitable for catalytic deoxidation to prepare high-purity hydrogen in the hydrogen production industry.

5. A catalyst prepared according to the preparation method according to any one of claims 1 to 4, suitable for catalytic deoxygenation to produce high-purity hydrogen in the hydrogen production industry.

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