Catalyst, preparation method and application thereof

Abstract

The invention provides a catalyst as well as a preparation method and application thereof, and relates to the technical field of catalysts. According to the catalyst, ruthenium-iridium alloy oxide is loaded on a high-porosity inorganic oxide carrier, the average particle size of the high-porosity inorganic oxide is 10-500 nm, and the BET specific surface area is not smaller than 200 m < 2 > / g. Preferably, the high-porosity inorganic oxide is high-porosity cerium dioxide. The catalyst disclosed by the invention has relatively high catalytic activity and durability, and also has relatively high catalytic activity under the condition of relatively few catalytic active components.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalysts, and relates to a catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] Proton exchange membrane (PEM) electrolysis of water is an environmentally friendly and efficient hydrogen production technology, which has the advantages of fast startup, low operating temperature, high efficiency, etc., and is suitable for the storage and application of renewable energy. During its operation, the anode catalyst is mainly responsible for the oxygen evolution reaction (OER), and the cathode catalyst is mainly responsible for the hydrogen evolution reaction (HER). Since the anode side is in a harsh environment of high potential, oxygen-rich and strong acidity for a long time, currently, iridium-based catalysts such as iridium oxide are mainly used as PEM electrolysis OER catalysts in industry. However, the resources of iridium are extremely limited, which restricts the large-scale application of PEM electrolysis water technology.

[0003] In order to reduce the cost of OER catalysts and improve their performance, researchers have developed supported catalysts, in which active noble metals (such as iridium, ruthenium, platinum, etc.) are loaded on carrier particles. Chinese Patent CN115786974A discloses a catalyst for water electrolysis, including a carrier and a noble metal oxide loaded thereon. The carrier is a non-noble metal inorganic oxide carrier, and the noble metal oxide includes at least one of iridium oxide and ruthenium oxide. Both the carrier and the noble metal oxide have oxygen vacancies, and the particle size of the noble metal oxide is 2 - 5 nm. Chinese Patent CN118563359A discloses an oxygen evolution catalyst for PEM water electrolysis, including: a carrier and a noble metal active component. The noble metal active component is loaded on the carrier. The carrier is titanium nitride, and the noble metal active component is a mixture of IrO2 and RuO2. The carrier accounts for 20% - 60% of the total mass of the catalyst, and the mass ratio of IrO2 to RuO2 is 1:0.25 - 1.5. IrO2 and RuO2 are compounded to form a synergistic effect. Compared with pure catalyst particles, the supported catalyst has a high dispersion degree of active substances, and both the electrochemical activity and stability are enhanced. However, there are still some technical challenges in the carrier material and loading method of the current supported catalyst. General particle carriers have problems such as uneven catalyst loading and catalyst shedding, as well as problems such as uneven active particle size, difficult to accurately control the loading amount, low catalytic efficiency, and insufficient durability.

[0004] Therefore, the technology of the existing supported OER catalysts needs to be further modified. Summary of the Invention

[0005] The applicant unexpectedly found that the composition and structural form of the carrier have an obvious influence on the performance of the OER catalyst. Based on this, the present invention provides a catalyst, a preparation method thereof, and an application thereof.

[0006] The technical solution of the present invention is as follows:

[0007] A catalyst, wherein the catalyst is ruthenium-iridium alloy oxide supported on a high-porosity inorganic oxide carrier;

[0008] The average particle size of the high-porosity inorganic oxide is 10 - 500 nm, and the BET specific surface area is not less than 200 m 2 / g.

[0009] Preferably, the inorganic oxide carrier is selected from cerium dioxide carriers.

[0010] Preferably, the molar ratio of ruthenium to iridium in the ruthenium-iridium alloy oxide is 0.1 - 2:1.

[0011] A method for preparing a catalyst, the steps comprising:

[0012] Mixing a high-porosity inorganic oxide dispersion, an iridium precursor solution, and a ruthenium precursor solution to obtain a mixed solution, adding a first basic substance solution and performing a first water bath reaction to obtain a colloid;

[0013] Drying the colloid to obtain a precursor solid, and then performing heat treatment, washing, and drying to obtain the catalyst;

[0014] The catalyst is ruthenium-iridium alloy oxide supported on a high-porosity inorganic oxide carrier.

[0015] Preferably, the high-porosity inorganic oxide dispersion is obtained by dispersing the high-porosity inorganic oxide obtained by reacting a salt precursor corresponding to the inorganic oxide, a second basic substance, and a pore-forming agent in water.

[0016] More preferably, the molar ratio of the salt precursor to the second basic substance is 1:1 - 20, and the weight ratio of the salt precursor to the pore-forming agent is 1:0.2 - 3.

[0017] More preferably, the pore-forming agent is selected from one or a combination of two or more of ammonium bicarbonate, polyvinylpyrrolidone, polymethyl methacrylate, starch, urea, dicyandiamide, thiourea, ethylenediaminetetraacetic acid, and melamine.

[0018] More preferably, the reaction includes a second water bath reaction and a calcination reaction.

[0019] Preferably, the ratio of the weight of the high-porosity inorganic oxide in the mixed solution to the sum of the weights of the iridium precursor and the ruthenium precursor is 1:0.1 - 10;

[0020] The molar ratio of the iridium precursor to the ruthenium precursor is 1:0.1 - 2.

[0021] The application of the catalyst described in any of the above technical solutions or the catalyst obtained by the preparation method described in any of the above technical solutions is used as the anode catalyst for proton exchange membrane electrolysis of water.

[0022] The beneficial effects of the present invention are as follows:

[0023] (1) The present invention uses a highly porous inorganic oxide as the catalyst carrier and a ruthenium-iridium alloy oxide as the catalyst active component. While achieving high catalytic activity and durability, the amount of active noble metal components can be reduced. Even at a relatively low loading of the ruthenium-iridium alloy oxide, the catalyst still has good catalytic performance.

[0024] (2) The present invention further uses a highly porous cerium dioxide carrier, and the effect of the carrier is better, further improving the catalytic activity and durability of the catalyst.

[0025] (3) The preparation method of the catalyst of the present invention uses a hydrothermal reaction, and there is no need for a filtration step, which can improve the utilization rate of noble metals. Description of the Drawings

[0026] Figure 1 SEM image of the highly porous cerium dioxide carrier obtained in Example 1.

[0027] Figure 2 TEM image of the catalyst obtained in Example 1.

[0028] Figure 3 Comparison of the catalytic activities of the catalyst of Example 1, commercial catalyst 1, and commercial catalyst 2.

[0029] Figure 4 Catalytic activity results of the catalyst of Example 4. Detailed Embodiments

[0030] The technical solutions of the present invention are further described and illustrated below through specific embodiments.

[0031] In order to improve the catalytic performance and durability of the supported catalyst and reduce the amount of active noble metal components, on the one hand, the present invention provides a catalyst, which is a ruthenium-iridium alloy oxide supported on a highly porous inorganic oxide carrier;

[0032] The average particle size of the highly porous inorganic oxide is 10 - 500 nm, and the BET specific surface area is not less than 200 m 2 / g.

[0033] The supported catalyst of the present invention uses a high-porosity, nanoscale inorganic oxide as the carrier and a ruthenium-iridium alloy oxide as the catalyst active ingredient, which can significantly improve the catalytic activity and durability of the catalyst and reduce the amount of precious metal active ingredient used. In the present invention, the high-porosity inorganic oxide is not particularly limited, and the inorganic oxide can be cerium dioxide, silicon dioxide, titanium dioxide, etc.

[0034] In some embodiments, the inorganic oxide carrier is selected from cerium dioxide carriers. Using a cerium dioxide carrier, cerium dioxide is a rare earth oxide and has a strong interaction with the ruthenium-iridium alloy oxide, with the following effects: (1) improving the stability and dispersibility of the precious metal active ingredient ruthenium-iridium alloy oxide loading, and the precious metal active ingredient can be more uniformly and stably dispersed on the surface of the high-porosity cerium dioxide; (2) cerium dioxide can enhance the catalytic performance of the ruthenium-iridium alloy oxide, so the amount of ruthenium-iridium alloy oxide can be reduced while maintaining the catalytic performance of the catalyst.

[0035] In some embodiments, the molar ratio of ruthenium to iridium in the ruthenium-iridium alloy oxide is 0.1-2:1. For example, the molar ratio can be any value among 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, etc.

[0036] On the other hand, the present invention provides a method for preparing a catalyst, and the steps include:

[0037] Mix a high-porosity inorganic oxide dispersion, an iridium precursor solution, and a ruthenium precursor solution to obtain a mixed solution, add a first basic substance solution and perform a first water bath reaction to obtain a colloid;

[0038] Dry the colloid to obtain a precursor solid, and then perform heat treatment, washing, and drying to obtain the catalyst of the present invention;

[0039] The catalyst is a ruthenium-iridium alloy oxide supported on a high-porosity inorganic oxide carrier. The average particle size of the high-porosity inorganic oxide carrier is 10-500 nm, and the BET specific surface area is not less than 200 m 2 / g.

[0040] In the catalyst preparation method of the present invention, the raw materials (high-porosity inorganic oxide, iridium precursor, and ruthenium precursor) are mixed and then subjected to a water bath reaction, followed by heat treatment, washing, and drying to obtain the product. There is no need to use a filtration method. After the first water bath reaction, the iridium precursor and ruthenium precursor form a colloid together with the high-porosity inorganic oxide, which can reduce the loss of precious metal components iridium and ruthenium. The yields of iridium and ruthenium can reach over 95%, even over 98%. The temperature of the above first water bath reaction can be 70 - 100°C, and the time can be 1 - 10 h. In the above preparation method, the heat treatment is heating in an atmosphere furnace or a tube furnace, the gas atmosphere is air or oxygen, the temperature is 200 - 600°C, and the time is 0.5 - 8 h; the washing method is pure water suction filtration, the drying temperature is 50 - 80°C, and the drying time is 1 - 24 hours.

[0041] In the present invention, the concentration of the high-porosity inorganic oxide dispersion can be 1 - 10 mg / mL, such as 1 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, 8 mg / mL, 10 mg / mL, etc., without any particular limitation; the iridium precursor can be chloroiridic acid, iridium trichloride, iridium trifluoride, iridium triiodide, iridium tetrachloride, iridium tetrafluoride, iridium pentafluoride, iridium hexafluoride, iridium acetylacetonate, dodecacarbonyltetrairidium, ammonium hexachloroiridate, iridium acetate, etc. The concentration of the iridium precursor solution can be 1 - 10 mg / mL, such as 1 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, 8 mg / mL, 10 mg / mL, etc., without any particular limitation; the ruthenium precursor can be ruthenium chloride, ruthenium nitrate, ruthenium nitrate, ruthenium oxalate, ruthenic acid, ruthenium acetate, etc. The concentration of the ruthenium precursor solution can be 1 - 10 mg / mL, such as 1 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, 8 mg / mL, 10 mg / mL, etc., without any particular limitation.

[0042] In some embodiments, the high-porosity inorganic oxide dispersion is obtained by dispersing the high-porosity inorganic oxide obtained by the reaction of the salt precursor corresponding to the inorganic oxide, the second basic substance, and the pore-forming agent in water.

[0043] In the present invention, there are no particular limitations on the above-mentioned first basic substance and second basic substance, which may be sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, lithium carbonate, ammonia water, etc. The function of the first basic substance and the second basic substance is to convert the precursor (such as iridium precursor, ruthenium precursor, etc.) into the corresponding hydroxide and form a colloid. Regarding the dosage of the first basic substance, it can be appropriately in excess relative to the ruthenium precursor and the iridium precursor to promote the conversion of the ruthenium precursor and the iridium precursor. For example, the ratio can be: the ratio of the sum of the molar amounts of the ruthenium precursor and the iridium precursor to the molar amount of the first basic substance is 1:4 - 50. For example, the ratio can be 1:4, 1:6, 1:8, 1:9, 1:10, 1:12, 1:15, 1:18, 1:20, 1:22, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, etc.

[0044] Taking inorganic oxide cerium dioxide as an example, the salt precursor can be cerium nitrate (or cerium nitrate hexahydrate), cerium trichloride, cerium sulfate, ammonium cerium nitrate, cerium oxalate, etc. There are no particular limitations on the concentrations of the salt precursor, the second basic substance, and the pore-forming agent, which can be 1 - 10 mg / ml respectively. For example, they can be 1 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, 8 mg / mL, 10 mg / mL, etc. In some embodiments, the molar ratio of the salt precursor to the second basic substance is 1:1 - 20. For example, the molar ratio can be any value among 1:1, 1:3, 1:4, 1:5, 1:6, 1:8, 1:10, 1:12, 1:13, 1:15, 1:16, 1:18, 1:20, etc.; the weight ratio of the salt precursor to the pore-forming agent is 1:0.2 - 3. For example, the weight ratio can be any value among 1:0.2, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:1, 1:1.2, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:2, 1:2.2, 1:2.5, 1:2.7, 1:2.8, 1:3, etc.

[0045] In the present invention, the gas generated by the decomposition of the pore-forming agent at high temperature expands and forms a large number of pores inside and on the surface of the carrier. In some embodiments, the pore-forming agent is selected from one or a combination of two or more of ammonium bicarbonate, polyvinylpyrrolidone, polymethyl methacrylate, starch, urea, dicyandiamide, thiourea, ethylenediaminetetraacetic acid, and melamine.

[0046] In some embodiments, the reaction (the reaction of the salt precursor, the second basic substance, and the pore-forming agent) includes a second water bath reaction and a calcination reaction. The temperature of the second water bath reaction can be 70 - 100 °C, and the time can be 1 - 10 h. After the second water bath reaction, the salt precursor and the pore-forming agent form a colloid, and the colloid is then dried and subjected to a calcination reaction to obtain a high-porosity inorganic oxide. The temperature of the calcination reaction can be 300 - 650 °C, and the time can be 0.5 - 10 h.

[0047] Specifically, when preparing the high-porosity inorganic oxide in the present invention, a method of generating gas and creating pores by decomposing the pore-forming agent at high temperature is adopted. The salt precursor, the second basic substance, and the pore-forming agent first undergo a second water bath reaction to form a colloid, and at this time, the pore-forming agent has not decomposed. After the colloid is dried, heat treatment (calcination reaction) is carried out. When drying, the pore-forming agent has not decomposed or has not completely decomposed. During heat treatment, the colloid component of inorganic hydroxide is converted into inorganic oxide, and the pore-forming agent decomposes and the formed gas expands violently, thereby forming a porous structure inside and on the surface of the inorganic oxide to obtain a high-porosity inorganic oxide support, such as a high-porosity cerium dioxide support.

[0048] In some embodiments, the ratio of the weight of the high-porosity inorganic oxide in the mixed solution to the sum of the weights of the iridium precursor and the ruthenium precursor is 1:0.1 - 10. For example, the ratio can be any value among 1:0.1, 1:0.2, 1:0.3, 1:0.5, 1:0.6, 1:0.8, 1:1, 1:1.2, 1:1.4, 1:1.5, 1:1.7, 1:1.8, 1:2, 1:2.2, 1:2.4, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5, 1:10, etc.;

[0049] The molar ratio of the iridium precursor to the ruthenium precursor is 1:0.1 - 2. For example, the molar ratio can be any value among 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, etc.

[0050] On the other hand, the present invention also provides an application of the catalyst described in any one of the above technical solutions or the catalyst obtained by the preparation method described in any one of the above technical solutions as an anode catalyst for proton exchange membrane electrolysis of water. The above-mentioned supported catalyst of the present invention as an anode catalyst for proton exchange membrane electrolysis of water has the characteristics of high catalytic activity and high durability, and also has good catalytic performance when the amount of the noble metal active component used is small.

[0051] The technical solutions of the present invention will be further described and explained according to the following embodiments. Unless otherwise specified, the parts mentioned in the following embodiments are parts by weight.

[0052] Example 1

[0053] A preparation method of a ruthenium-iridium alloy catalyst supported on cerium dioxide with high porosity is as follows:

[0054] Weigh 100 mg of cerium nitrate hexahydrate and dissolve it in 50 mL of ultrapure water to obtain an aqueous cerium nitrate solution; weigh 120 mg of sodium hydroxide powder and dissolve it in 50 mL of ultrapure water to obtain an aqueous sodium hydroxide solution; weigh 90 mg of urea powder and dissolve it in 50 mL of ultrapure water to obtain a urea solution.

[0055] Mix and stir the above-mentioned aqueous cerium nitrate solution, aqueous sodium hydroxide solution and urea solution, and carry out a water bath heating reaction. The heating temperature is 70 °C and the heating time is 2 hours to obtain a colloid. The colloid is placed in a blast drying oven at 60 °C and dried for 24 hours to obtain a pre-dried solid. The pre-dried solid is heated in a tubular furnace under an air atmosphere. The heating rate is 5 °C / min, heated to 450 °C, kept at a constant temperature for 2 hours, and naturally cooled to room temperature to obtain a heat-treated product. The heat-treated product is washed with pure water and filtered by suction. The conductivity of the last filtrate is not more than 2 μs / cm. The filter cake after suction filtration is placed in a vacuum drying oven at 60 °C and dried for 24 hours to obtain a cerium dioxide support with high porosity, with a weight of 39.5 mg. The SEM image of the cerium dioxide support with high porosity is as shown in the appendix Figure 1 It can be seen that the support has abundant pores. The BET specific surface area of the cerium dioxide support with high porosity is measured to be 280 m 2 / g, and the average particle size is 15 nm.

[0056] Take 4 mg of the above-mentioned cerium dioxide support with high porosity and disperse it in 2 mL of pure water to obtain a cerium dioxide support dispersion; weigh 10 mg of iridium tetrachloride and dissolve it in 5 mL of ultrapure water to obtain an aqueous iridium tetrachloride solution; weigh 10 mg of ruthenium trichloride and dissolve it in 5 mL of ultrapure water to obtain an aqueous ruthenium trichloride solution; mix the cerium dioxide support dispersion, the aqueous iridium tetrachloride solution and the aqueous ruthenium trichloride solution, stir at room temperature for 24 hours, add 20 ml of a 1 mg / mL aqueous sodium hydroxide solution, heat in a water bath to 80 °C, and react for 3 hours to obtain a colloid. The colloid is placed in a blast drying oven at 60 °C and dried for 24 hours to obtain a solid. The solid is ground and then placed in a quartz boat and heat-treated in a tubular furnace under an air atmosphere. The heating rate is 5 °C / min, heated to 300 °C, kept at a constant temperature for 2 hours, and then naturally cooled to room temperature.

[0057] The heat-treated product was filtered by suction with pure water and dried in a blast drying oven at 60 °C for 24 hours to obtain 19.2 mg of a ruthenium-iridium alloy catalyst supported on cerium dioxide with high porosity. The TEM image of the catalyst is shown in the appendix Figure 2 As shown, the black part is the high-porosity support, and the light gray part around it is the ruthenium-iridium alloy oxide catalyst with a particle size of several nanometers. It was measured that the total yield of ruthenium and iridium was 98.6%, and the weight content of the active component ruthenium-iridium alloy oxide in the ruthenium-iridium alloy catalyst supported on high-porosity cerium dioxide was 74.3%.

[0058] LSV curve test method: The test equipment is an electrochemical workstation (Chenhua CHI660E) and a rotating disk electrode (PINE, 0.196 cm 2 glassy carbon electrode). The catalyst was configured into a slurry (concentration: 2 mg / ml), and 6 μL of the slurry was dropped on the rotating disk electrode. The catalyst loading was 0.2 mg / cm 2 and air-dried naturally. 0.1 M perchloric acid was used as the electrolyte, the standard hydrogen electrode was used as the reference electrode, and the carbon rod was used as the counter electrode. During the test, the rotation speed of the sample electrode was 1600 rpm, the sweep rate of the LSV test program was set to 2 mV / s, and the test was repeated until the LSV curves coincided. The data of the last cycle after coincidence was taken, and the overpotential was the voltage value corresponding to a current density of 10 mA / cm 2 minus 1.23 volts.

[0059] Appendix Figure 3 This shows the comparison of the catalytic performance of the catalyst of this example, commercial catalyst 1 (iridium oxide), and commercial catalyst 2 (iridium oxide supported on titanium dioxide). It can be seen that at a current density of 10 mA / cm 2 , the overpotential of the catalyst of this example was 251 mV, while the overpotentials of commercial catalyst 1 and commercial catalyst 2 were 299 mV and 318 mV respectively. The catalytic activity of the catalyst prepared in Example 1 was much higher than that of the commercial catalysts.

[0060] The catalyst of this example was tested for catalytic activity recycling. The test was carried out continuously for 5 times. After each test, it was washed with ultrapure water and dried in a blast drying oven at 60 °C for 24 h. The overpotentials corresponding to the second test, the third test, the fourth test, and the fifth test were 249 mV, 254 mV, 254 mV, and 257 mV respectively, showing good catalytic stability.

[0061] Comparative Example 1

[0062] The difference between this comparative example and Example 1 is that in Example 1, when preparing the supported catalyst, the high-porosity cerium dioxide support was replaced with cerium dioxide (without pores) with an equal weight and an average particle size of 20 nm, and the other steps remained unchanged. According to the method of Example 1, it was measured that at 10 mA / cm 2The overpotential of the catalyst in this comparative example at the current density was 286 mV.

[0063] According to the method of catalytic activity application test in Example 1, the overpotentials corresponding to the second test, the third test, the fourth test, and the fifth test were 289 mV, 295 mV, 302 mV, and 311 mV respectively, and the catalytic activity deteriorated significantly.

[0064] Example 2

[0065] The difference between this example and Example 1 is that in Example 1, iridium tetrachloride was adjusted from 10 mg to 1 mg, ruthenium trichloride was adjusted from 10 mg to 1 mg, and the 1 mg / mL sodium hydroxide aqueous solution was adjusted from 20 ml to 2 ml. The remaining steps remained unchanged. The weight content of the active ingredient ruthenium-iridium alloy oxide in the high-porosity supported catalyst obtained in this example was measured to be 24.1%. According to the method of Example 1, when the current density was 10 mA / cm 2 the overpotential of the supported catalyst in this example was 256 mV. According to the method of catalytic activity application test in Example 1, the overpotential at the fifth test was 262 mV. Therefore, even when the content of the noble metal active ingredient in the catalyst of the present invention is low, it has good catalytic performance.

[0066] Example 3

[0067] The difference between this example and Example 2 is that in Example 2, ruthenium trichloride was adjusted from 1 mg to 0.1 mg, and the 1 mg / mL sodium hydroxide aqueous solution was adjusted from 20 ml to 2.2 ml. The remaining steps remained unchanged. According to the method of Example 1, when the current density was 10 mA / cm 2 the overpotential of the supported catalyst in this example was 264 mV.

[0068] Example 4

[0069] The difference between this example and Example 1 is that in Example 1, when preparing the cerium dioxide support, 90 mg of urea powder was replaced by 150 mg of polyvinylpyrrolidone K30; when preparing the supported catalyst, iridium tetrachloride was adjusted from 10 mg to 2 mg, ruthenium trichloride was adjusted from 10 mg to 1 mg, and the 1 mg / mL sodium hydroxide aqueous solution was adjusted from 20 ml to 5 ml. The remaining steps remained unchanged.

[0070] The BET specific surface area of the obtained high-porosity cerium dioxide support was 330 m 2 / g, and the average particle size was 27 nm 。

[0071] According to the method of Example 1, when the current density was 10 mA / cm 2The overpotential of the supported catalyst in this example at a current density of 10 mA / cm² is 243 mV, as shown in the appendix. Figure 4 According to the method for testing the catalytic activity application in Example 1, the overpotentials at the 5th and 10th tests are 247 mV and 251 mV respectively, showing good catalytic stability.

[0072] Example 5

[0073] The difference between this example and Example 4 is that when preparing the highly porous cerium dioxide support, the polyvinylpyrrolidone K30 is adjusted from 90 mg to 60 mg. The remaining steps remain unchanged.

[0074] The BET specific surface area of the obtained highly porous cerium dioxide support is 260 m² / g, and the average particle size is 22 nm. 2 / g, and the average particle size is 22 nm. 。

[0075] According to the method of Example 1, the overpotential of the supported catalyst in this example at a current density of 10 mA / cm² is 255 mV. 2 The overpotential of the supported catalyst in this example at a current density of 10 mA / cm² is 255 mV.

[0076] Example 6

[0077] The difference between this example and Example 4 is that when preparing the highly porous cerium dioxide support, the polyvinylpyrrolidone K30 is adjusted from 90 mg to 200 mg. The remaining steps remain unchanged.

[0078] The BET specific surface area of the obtained highly porous cerium dioxide support is 350 m² / g, and the average particle size is 30 nm. 2 / g, and the average particle size is 30 nm. 。

[0079] According to the method of Example 1, the overpotential of the supported catalyst in this example at a current density of 10 mA / cm² is 251 mV. 2 The overpotential of the supported catalyst in this example at a current density of 10 mA / cm² is 251 mV.

[0080] Example 7

[0081] The difference between this example and Example 4 is that in Example 4, when preparing the supported catalyst, the highly porous cerium dioxide support is replaced with an equal weight of mesoporous silica (average particle size 30 nm, BET specific surface area 550 m² / g). The remaining steps remain unchanged. According to the method of Example 1, the overpotential of the catalyst in this example at a current density of 10 mA / cm² is 276 mV. According to the method for testing the catalytic activity application in Example 1, the overpotentials at the 5th and 10th tests are 285 mV and 293 mV respectively, showing good catalytic stability. 2 / g). The remaining steps remain unchanged. According to the method of Example 1, the overpotential of the catalyst in this example at a current density of 10 mA / cm² is 276 mV. According to the method for testing the catalytic activity application in Example 1, the overpotentials at the 5th and 10th tests are 285 mV and 293 mV respectively, showing good catalytic stability. 2 The overpotential of the catalyst in this example at a current density of 10 mA / cm² is 276 mV. According to the method for testing the catalytic activity application in Example 1, the overpotentials at the 5th and 10th tests are 285 mV and 293 mV respectively, showing good catalytic stability.

[0082] Example 8

[0083] The difference between this embodiment and Embodiment 4 is as follows: In Embodiment 1, when preparing the supported catalyst, the high-porosity cerium dioxide support is replaced with an equal weight of mesoporous titanium dioxide (average particle size 28 nm, BET specific surface area 470 m 2 / g). The remaining steps remain unchanged. According to the method of Embodiment 1, the overpotential of the catalyst in this embodiment was measured to be 270 mV at a current density of 10 mA / cm 2 ². According to the method for testing the catalytic activity application in Embodiment 1, the overpotentials at the 5th test and the 10th test were 277 mV and 289 mV respectively, showing good catalytic stability.

[0084] As described above, the basic principles, main features and advantages of the present invention have been shown and described. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments are only preferred embodiments of the present invention, and the scope of implementation of the present invention cannot be limited thereby. That is, equivalent changes and modifications made according to the scope of the present invention patent and the content of the specification should still fall within the scope covered by the present invention. The scope of protection required by the present invention is defined by the appended claims and their equivalents.

Claims

1. A catalyst, characterized in that, The catalyst is ruthenium-iridium alloy oxide supported on a high-porosity inorganic oxide carrier; The average particle size of the high-porosity inorganic oxide is 10 - 500 nm, and the BET specific surface area is not less than 200 m 2 / g.

2. The catalyst according to claim 1, characterized in that, The inorganic oxide carrier is selected from cerium dioxide carriers.

3. The catalyst according to claim 1, characterized in that, The molar ratio of ruthenium to iridium in the ruthenium-iridium alloy oxide is 0.1-2:

1.

4. A method for preparing a catalyst, characterized in that the steps It includes: Mixing a high-porosity inorganic oxide dispersion, an iridium precursor solution, and a ruthenium precursor solution to obtain a mixed solution, adding a first alkaline substance solution and performing a first water bath reaction to obtain a colloid; Drying the colloid to obtain a precursor solid, and then performing heat treatment, washing, and drying to obtain the catalyst; The catalyst is ruthenium-iridium alloy oxide supported on a high-porosity inorganic oxide carrier.

5. The preparation method of the catalyst according to claim 4, characterized in that, The high-porosity inorganic oxide dispersion is obtained by dispersing high-porosity inorganic oxides obtained by reacting a salt precursor corresponding to the inorganic oxide, a second alkaline substance, and a pore-forming agent in water.

6. The preparation method of the catalyst according to claim 5, characterized in that, The molar ratio of the salt precursor to the second alkaline substance is 1:1-20, and the weight ratio of the salt precursor to the pore-forming agent is 1:0.2-3.

7. The preparation method of the catalyst according to claim 5, characterized in that, The pore-forming agent is selected from one or a combination of two or more of ammonium bicarbonate, polyvinylpyrrolidone, polymethyl methacrylate, starch, urea, dicyandiamide, thiourea, ethylenediaminetetraacetic acid, and melamine.

8. The preparation method of the catalyst according to claim 5, characterized in that, The reaction includes a second water bath reaction and a calcination reaction.

9. The preparation method of the catalyst according to claim 4, wherein, The ratio of the weight of the high-porosity inorganic oxide in the mixed solution to the sum of the weights of the iridium precursor and the ruthenium precursor is 1:0.1-10; The molar ratio of the iridium precursor to the ruthenium precursor is 1:0.1-2.

10. Use of the catalyst according to any one of claims 1 to 3 or the catalyst obtained by the preparation method according to any one of claims 4 to 9, characterized in that, As the anode catalyst for proton exchange membrane electrolysis of water.

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