Iridium oxide catalyst, preparation method and application

Abstract

The invention provides an iridium oxide catalyst, a preparation method and application, and relates to the technical field of metal catalysts. The iridium oxide catalyst has a nanowire structure, the diameter of the iridium oxide catalyst is 1-10 nm, and the length-diameter ratio of the iridium oxide catalyst is 10-2000. The preparation method comprises the following steps: adding an iridium source, an auxiliary ligand and a reaction aid into water, uniformly dissolving, heating for reaction, collecting solids, and cleaning to obtain a pre-product; and carrying out heat treatment on the pre-product to obtain the iridium oxide catalyst. The iridium oxide catalyst with the nanowire structure can be used as an anode catalyst for electro-catalysis water decomposition or an anti-antipole catalyst of a fuel cell.

Description

Technical Field

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

[0002] As a cutting-edge technology for the production of high-purity green hydrogen by proton exchange membrane (PEM) water electrolysis, compared with alkaline electrolysis of water (ALK), it has advantages such as fast system response speed, high current density, compact system design, high gas purity, etc., and can fully couple the characteristics of renewable energy volatility, becoming the focus of attention in water electrolysis technology. However, the main challenge faced by PEM water electrolysis technology lies in the high cost of noble metal catalysts (especially iridium-based catalysts). Current commercial PEM electrolysis water systems rely on high-loading iridium-based catalysts, but the scarcity and high price of iridium resources severely limit the economic efficiency of the technology. In the future, a significant reduction in iridium loading (such as the U.S. Department of Energy (DOE) target of 0.5 mg / cm 2 or 0.1 g / kW) is required, while maintaining a high current density (such as 3.0 A / cm 2 @1.8 V), to promote the large-scale commercial application of PEM water electrolysis technology. Therefore, there is an urgent need to develop an iridium oxide catalyst with both high activity and good stability to reduce the usage amount of noble metal iridium in electrolyzer equipment. Summary of the Invention

[0003] The applicant's previously disclosed patent CN119061425A obtained an iridium oxide catalyst with a foam structure by adding an auxiliary ligand and a reaction assistant to an iridium source, using an alcohol aqueous solution as a reaction solvent and reacting at room temperature. The inventor adjusted the alcohol aqueous solution to water and reacted under heating, and found that an iridium oxide catalyst with a nanowire structure was obtained. Based on this, the present invention provides an iridium oxide catalyst, a preparation method and an application thereof.

[0004] The technical solution of the present invention is as follows:

[0005] An iridium oxide catalyst, wherein the iridium oxide catalyst has a nanowire structure, a diameter of 1-10 nm, and an aspect ratio of 5-2000.

[0006] A preparation method of an iridium oxide catalyst, comprising the following steps:

[0007] Dissolve an iridium source, an auxiliary ligand and a reaction assistant in water uniformly, heat and react, then collect the solid and wash to obtain a pre-product;

[0008] The pre-product is heat-treated to obtain the iridium oxide catalyst;

[0009] The iridium oxide catalyst has a nanowire structure, a diameter of 1-10 nm, and an aspect ratio of 10-2000.

[0010] Preferably, the iridium source is selected from one or a combination of two or more of iridium trichloride, iridium tetrachloride, iridic acid and its salts, and iridium acetate.

[0011] Preferably, the auxiliary ligand is selected from one or a combination of two or more of amide organic compounds and organic amine compounds.

[0012] Preferably, the reaction promoter is selected from one or a combination of two or more of nitrates.

[0013] Preferably, the molar ratio of the iridium source to the auxiliary ligand is 0.01-1:1.

[0014] Preferably, the molar ratio of the iridium source to the reaction promoter is 0.001-1:1.

[0015] Preferably, the reaction temperature of the heating reaction is 70-120 °C.

[0016] Preferably, the temperature of the heat treatment is 350-600 °C.

[0017] An application of the iridium oxide catalyst described above or the iridium oxide catalyst obtained by the preparation method of the iridium oxide catalyst described in any one of the above embodiments, as an anode catalyst for electrocatalytic water splitting or an anti-polarization catalyst for a fuel cell.

[0018] The beneficial effects of the present invention are: in the preparation of the iridium oxide catalyst of the present invention, an orientation growth regulator and an oxidation promoter are added, and by controlling the reaction temperature and the reaction solvent, a nanowire iridium oxide catalyst at the nanoscale is obtained, which can effectively improve the efficiency of hydrogen production by proton exchange membrane electrolysis of water and reduce the equipment cost and energy consumption. Description of the Drawings

[0019] Figure 1 It is a SEM image of the iridium oxide catalyst obtained in Example 1.

[0020] Figure 2 It is a TEM image of the iridium oxide catalyst obtained in Example 1.

[0021] Figure 3 It is a polarization curve graph of the OER test of the iridium oxide catalyst obtained in Example 1.

[0022] Figure 4 It is a test result graph of the membrane electrode of the iridium oxide catalyst obtained in Example 1.

[0023] Figure 5 It is a TEM image of the iridium oxide catalyst obtained in Comparative Example 1.

[0024] Figure 6SEM image of the iridium oxide catalyst obtained in Example 2.

[0025] Figure 7 TEM image of the iridium oxide catalyst obtained in Example 2.

[0026] Figure 8 Membrane electrode test result graph of the iridium oxide catalyst obtained in Example 2. Detailed implementation manners

[0027] The technical solutions of the present invention will be further described and illustrated through the following detailed implementation manners.

[0028] On the one hand, the present invention provides an iridium oxide catalyst. The iridium oxide catalyst has a nanowire structure, with a diameter of 1 - 10 nm and an aspect ratio of 5 - 2000.

[0029] For nanoscale catalysts, aggregation is an important factor affecting catalytic activity and stability. The iridium oxide catalyst of the present invention has a nanowire structure, a relatively low diameter, and a relatively high aspect ratio, which can effectively avoid aggregation and improve catalytic activity and stability.

[0030] Furthermore, the aspect ratio of the iridium oxide catalyst with a nanowire structure of the present invention can be 5 - 500.

[0031] On the other hand, the present invention provides a method for preparing an iridium oxide catalyst, comprising the following steps:

[0032] Dissolve an iridium source, an auxiliary ligand, and a reaction aid in water uniformly, heat the reaction, collect the solid matter, and wash it to obtain a pre-product;

[0033] The pre-product is subjected to heat treatment to obtain the iridium oxide catalyst;

[0034] The iridium oxide catalyst has a nanowire structure, a diameter of 1 - 10 nm, and an aspect ratio of 10 - 2000.

[0035] The present invention prepares an iridium oxide catalyst with a nanowire structure by a relatively simple method. Adding an auxiliary ligand can adjust the growth orientation of the catalyst and form a nanowire structure. The purpose of adding a reaction aid is to accelerate the oxidation process, form iridium oxide faster, and improve the reaction yield.

[0036] In some embodiments, the iridium source is selected from one or a combination of two or more of iridium trichloride, iridium tetrachloride, chloroiridic acid and its salts, and iridium acetate.

[0037] In the present invention, the role of the auxiliary ligand is to act as an orientation growth regulator, enabling the product iridium oxide to form a nanowire structure. In some embodiments, the auxiliary ligand is selected from one or a combination of two or more of amide organic compounds and organic amine compounds. There are no particular limitations on the amide organic compounds, which may be formamide, carbamide, acetamide, nicotinamide, N-methylsuccinamide, cinnamamide, N,N-dimethylacetamide, N,N-diethylacetamide, etc. There are no particular limitations on the organic amine compounds, which may be dicyandiamide, melamine, triethylamine, aminonitrile, melamine cyanurate, etc. More preferably, the organic amine compound is a cyanamide compound.

[0038] In the present invention, the reaction auxiliary is an oxidation promoter, which is beneficial to accelerating the oxidation reaction and increasing the yield of the iridium oxide catalyst. In some embodiments, the reaction auxiliary is selected from one or a combination of two or more of nitrates. By way of example, it may be sodium nitrate, potassium nitrate, calcium nitrate, magnesium nitrate, lithium nitrate, etc.

[0039] In some embodiments, the molar ratio of the iridium source to the auxiliary ligand is 0.01-1:1. By way of example, the molar ratio of the iridium source to the auxiliary ligand may be any value among 0.01:1, 0.05:1, 0.08:1, 0.1:1, 0.12:1, 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, 0.55:1, 0.6:1, 0.65:1, 0.7:1, 0.75:1, 0.8:1, 0.85:1, 0.9:1, 0.95:1, 1:1, etc., without any particular limitations. Further, the molar ratio of the iridium source to the auxiliary ligand may be 0.07-0.5:1.

[0040] In some embodiments, the molar ratio of the iridium source to the reaction auxiliary is 0.001-1:1. By way of example, the molar ratio of the iridium source to the reaction auxiliary may be any value among 0.001:1, 0.005:1, 0.01:1, 0.02:1, 0.05:1, 0.07:1, 0.08:1, 0.1:1, 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, 0.55:1, 0.6:1, 0.65:1, 0.7:1, 0.75:1, 0.8:1, 0.85:1, 0.9:1, 0.95:1, 1:1, etc., without any particular limitations. Further, the molar ratio of the iridium source to the reaction auxiliary may be 0.01-0.1:1.

[0041] In the present invention, there is no particular limitation on the amount of water used during the reaction. It is preferably an amount that can dissolve the iridium source, co-ligand, and reaction assistant. However, preferably, the amount of water is quantitatively added based on the concentration of the iridium source, and the concentration of the iridium source can be 10 - 100 mg / ml, such as 10 mg / ml, 20 mg / ml, 30 mg / ml, 40 mg / ml, 50 mg / ml, 60 mg / ml, 70 mg / ml, 80 mg / ml, 90 mg / ml, 100 mg / ml, etc. To increase the dissolution rate of the iridium source, co-ligand, and reaction assistant, heated water can be used, such as water at 50 - 90°C.

[0042] In some embodiments, the reaction temperature for the heating reaction is 70 - 120°C. For example, the reaction temperature for the heating reaction can be any value among 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, etc., without any particular limitation. The reaction time can be 5 - 24 hours.

[0043] In some embodiments, the temperature for the heat treatment is 350 - 600°C. For example, the temperature for the heat treatment can be any value among 350°C, 370°C, 400°C, 420°C, 450°C, 480°C, 500°C, 520°C, 550°C, 570°C, 600°C, etc., without any particular limitation. The time for the heat treatment can be 1 - 5 hours.

[0044] After the heat treatment of the above preparation method, the following impurity removal steps can also be included: soaking the product after the heat treatment in a sulfuric acid solution, and then repeatedly washing and filtering with ultrapure water until the conductivity of the filtrate does not exceed 5 S / cm. The collected product is then dried to obtain the iridium oxide catalyst with a nanowire structure. There is no particular limitation on the concentration of the above sulfuric acid solution. For example, it can be 0.1 - 1 mol / L, and the soaking time can be 0.1 - 5 hours.

[0045] On the other hand, the present invention proposes an application of the iridium oxide catalyst described above or the iridium oxide catalyst obtained by the preparation method of any one of the above embodiments as an anode catalyst for electrocatalytic water splitting or an anti-polarization catalyst for a fuel cell. The iridium oxide catalyst of the present invention can effectively improve the efficiency of proton exchange membrane electrolysis for hydrogen production, and reduce equipment costs and energy consumption.

[0046] The technical solutions of the present invention will be further described and illustrated according to the following examples.

[0047] Example 1

[0048] Dissolve 200 mg of iridium(III) chloride (0.67 mmol) powder in 5 ml of ultrapure water at 80 °C. Then, add 4 g of potassium nitrate (40 mmol) and 300 mg of urea (5 mmol) in sequence. After stirring to dissolve, place the mixture in a constant temperature reaction at 80 °C for 10 h. After the reaction, use a rotary evaporator to evaporate the solvent in the solution to dryness to obtain the precursor product. Then, grind and crush the precursor product and place it in a high-temperature tube furnace. Program the temperature to rise to 450 °C and hold for heat treatment for 2 h. After cooling to room temperature, soak the obtained product in a 0.5 mol / L sulfuric acid solution for 2 h. Take it out and wash it repeatedly with ultrapure water until the ionic conductivity in the filtrate is <5 S / cm. Collect the product and vacuum dry it overnight in an oven at 60 °C to obtain the iridium oxide catalyst, and the calculated yield is 99.4%.

[0049] The SEM image of the iridium oxide catalyst obtained in this example is as shown in the appendix Figure 1 as shown, and the TEM image is as shown in the appendix Figure 2 as shown. It can be seen that there is an obvious nanowire structure. The diameter of the nanowires is about 2 nm, and the length is about 20 nm for some and more than 50 nm for some. High-resolution TEM microarea analysis (not shown) shows that there are obvious lattice fringes of the (101) crystal plane of iridium oxide in the nanowires.

[0050] Electrocatalytic oxygen evolution reaction (OER) test: Use the prepared iridium oxide catalyst for the oxygen evolution reaction test in an acidic environment. Adopt a three-electrode test system. The working electrode is a rotating disk electrode, the counter electrode is a carbon rod, and the reference electrode uses a standard hydrogen electrode. Weigh 4 mg of the catalyst and disperse it in a mixed solution of 300 μL of isopropanol and 190 μL of ultrapure water. After ultrasonic dispersion for 30 min, further add 10 μL of Nafion solution and continue ultrasonic for 15 min. Then, transfer 10 μL of the prepared slurry ink and evenly drop it on a glassy carbon electrode with a diameter of 5 mm. After evaporation and drying at room temperature, perform electrochemical testing. The electrolyte is 0.1 mol / L perchloric acid solution, and the test speed of the polarization curve is 2 mV / s. The polarization curve test results of the iridium oxide catalyst obtained in this example are as shown in the appendix Figure 3 as shown. At a current density of 10 mA / cm 2 , the overpotential of the iridium oxide nanowire catalyst is 275 mV, showing good oxygen evolution catalytic activity.

[0051] Membrane electrode preparation and testing: Ultrasonically spray the iridium oxide nanowire catalyst prepared in this example on the anode side of the proton exchange membrane (N115). Commercially available platinum-carbon catalyst is selected for the cathode side. After the membrane electrode MEA is prepared, assemble it with the gas diffusion layer, bipolar plate, etc. into a PEM electrolytic water single cell device, and then perform membrane electrode performance testing. The results are as shown in the appendix Figure 4 as shown. At an anode iridium loading of 0.7 mg / cm 2, the cathode Pt loading is 0.5 mg / cm 2 , and the current density is 2 A / cm 2 under the test condition of 60 °C, and the electrolysis potential is 1.833 V. Under the test condition of 80 °C and a current density of 2 A / cm 2 , the electrolysis potential is only 1.762 V, indicating that the catalyst of this example has good membrane electrode device performance.

[0052] Comparative Example 1

[0053] The difference between this comparative example and Example 1 is that potassium nitrate is not added in Example 1, and the remaining steps remain unchanged. The yield of the iridium oxide catalyst is calculated to be 70.7%.

[0054] The catalyst structure of this comparative example is as shown in the appendix Figure 5 , which has obvious differences from the catalyst structure of Example 1.

[0055] Example 2

[0056] Dissolve 250 mg of iridium(IV) chloride (0.75 mmol) powder in 5 ml of ultrapure water at 80 °C, then add 6 g of sodium nitrate (70.6 mmol) and 500 mg of urea (8.33 mmol) in sequence. After stirring and dissolving, place it in a constant temperature reaction at 80 °C for 12 h. After the reaction, use a rotary evaporator to evaporate the solvent in the solution to dryness to obtain a precursor product. Then grind and crush the precursor product and place it in a high-temperature tubular furnace. Program the temperature to 450 °C and keep it heat-treated for 2 h. After cooling to room temperature, soak the obtained product in a 0.5 mol / L sulfuric acid solution for 2 hours, take it out, and wash it repeatedly with ultrapure water until the ionic conductivity in the filtrate < 5 S / cm, collect the product, and vacuum dry it overnight in an oven at 60 °C to obtain an iridium oxide catalyst, and calculate the yield to be 99.2%.

[0057] The SEM image of the iridium oxide catalyst obtained in this example is as shown in the appendix Figure 6 , and the TEM image is as shown in the appendix Figure 7 , and it can be seen that the obtained iridium oxide catalyst has an obvious nanowire structure.

[0058] The iridium oxide catalyst obtained in this example is tested according to the membrane electrode test method of Example 1. The anode iridium loading is 0.6 mg / cm 2 , and the cathode Pt loading is 0.5 mg / cm 2 , and the results are as shown in the appendix Figure 8 , and under the test condition of 60 °C, the current density is 2 A / cm 2 , and the electrolysis potential is 1.854 V. Under the test condition of 80 °C and a current density of 2 A / cm 2 , the electrolysis potential is only 1.772 V, showing good membrane electrode device performance.

[0059] Example 3

[0060] Dissolve 300 mg of iridium(IV) chloride powder (0.90 mmol) in 5 ml of ultrapure water at 80 °C. Then, add 3 g of sodium nitrate (35 mmol), 2 g of potassium nitrate (20 mmol), and 500 mg of urea (8.33 mmol) in sequence. After stirring and dissolving, place the mixture in a constant temperature reaction at 90 °C for 12 h. After the reaction is completed, evaporate the solvent in the solution to dryness using a rotary evaporator to obtain a precursor product. Then, grind and crush the precursor product and place it in a high-temperature tubular furnace. Program the temperature to 550 °C and hold for heat treatment for 2 h. After cooling to room temperature, immerse the obtained product in a 0.5 mol / L sulfuric acid solution for 2 h, take it out, and wash it repeatedly with ultrapure water until the ionic conductivity in the filtrate is <5 S / cm. Collect the product and dry it overnight in a vacuum oven at 60 °C to obtain an iridium oxide catalyst, and the calculated yield is 98.9%.

[0061] The iridium oxide catalyst obtained in this example was tested according to the membrane electrode test method of Example 1. The iridium loading on the anode was 0.6 mg / cm 2 , and the Pt loading on the cathode was 0.5 mg / cm 2 . Under the test conditions of 60 °C, the electrolysis potential was 1.861 V at a current density of 2 A / cm 2 . At a current density of 2 A / cm 2 under the test conditions of 80 °C, the electrolysis potential was only 1.792 V, showing good membrane electrode device performance.

[0062] Example 4

[0063] Dissolve 200 mg of iridium(III) chloride powder (0.70 mmol) in 10 ml of ultrapure water at 70 °C. Then, add 4 g of potassium nitrate (40 mmol) and 350 mg of dicyandiamide (4.13 mmol) in sequence. After stirring and dissolving, place the mixture in a constant temperature reaction at 80 °C for 12 h. After the reaction is completed, evaporate the solvent in the solution to dryness using a rotary evaporator to obtain a precursor product. Then, grind and crush the precursor product and place it in a high-temperature tubular furnace. Program the temperature to 450 °C and hold for heat treatment for 2 h. After cooling to room temperature, immerse the obtained product in a 0.5 mol / L sulfuric acid solution for 2 h, take it out, and wash it repeatedly with ultrapure water until the ionic conductivity in the filtrate is <5 S / cm. Collect the product and dry it overnight in a vacuum oven at 60 °C to obtain an iridium oxide catalyst, and the calculated yield is 98.3%.

[0064] The iridium oxide catalyst obtained in this example was tested according to the membrane electrode test method of Example 1. The iridium loading on the anode was 0.6 mg / cm 2 , and the Pt loading on the cathode was 0.5 mg / cm 2, the current density is 2 A / cm² under the test condition of 60 °C 2 and the electrolysis potential is 1.855 V. When the current density is 2 A / cm² under the test condition of 80 °C 2 , the electrolysis potential is only 1.783 V, showing good performance of the membrane electrode device.

[0065] Example 5

[0066] Dissolve 250 mg of iridium(III) chloride (0.84 mmol) powder in 10 ml of ultrapure water at 80 °C, then add 2 g of sodium nitrate (23.5 mmol), 2 g of potassium nitrate (20 mmol) and 400 mg of melamine (3.17 mmol) in sequence. After stirring and dissolving, place the mixture in a constant temperature reaction at 80 °C for 12 h. After the reaction, use a rotary evaporator to evaporate the solvent in the solution to dryness to obtain a precursor product. Then grind and crush the precursor product and place it in a high-temperature tube furnace. Program the temperature to 500 °C and keep it heat-treated for 2 h. After cooling to room temperature, soak the obtained product in 0.5 mol / L sulfuric acid solution for 2 hours, take it out, wash it repeatedly with ultrapure water until the ionic conductivity in the filtrate < 5 S / cm, collect the product, and vacuum dry it overnight in an oven at 60 °C to obtain an iridium oxide catalyst, and the calculated yield is 98.6%.

[0067] The iridium oxide catalyst obtained in this example was tested according to the membrane electrode test method of Example 1. The iridium loading on the anode is 0.6 mg / cm² 2 , and the Pt loading on the cathode is 0.5 mg / cm² 2 , the current density is 2 A / cm² under the test condition of 60 °C 2 and the electrolysis potential is 1.875 V. When the current density is 2 A / cm² under the test condition of 80 °C 2 , the electrolysis potential is only 1.823 V, showing good performance of the membrane electrode device.

[0068] Example 6

[0069] Dissolve 250 mg of iridium(IV) chloride (0.75 mmol) powder in 8 ml of ultrapure water at 80 °C, then add 7.5 mmol of sodium nitrate and 6 mmol of urea in sequence. After stirring and dissolving, place the mixture in a constant temperature reaction at 80 °C for 18 h. After the reaction, use a rotary evaporator to evaporate the solvent in the solution to dryness to obtain a precursor product. Then grind and crush the precursor product and place it in a high-temperature tube furnace. Program the temperature to 480 °C and keep it heat-treated for 2 h. After cooling to room temperature, soak the obtained product in 0.5 mol / L sulfuric acid solution for 2 hours, take it out, wash it repeatedly with ultrapure water until the ionic conductivity in the filtrate < 5 S / cm, collect the product, and vacuum dry it overnight in an oven at 60 °C to obtain an iridium oxide catalyst, and the calculated yield is 97.2%.

[0070] The iridium oxide catalyst obtained in this example was tested according to the membrane electrode test method of Example 1, with an anode iridium loading of 0.6 mg / cm 2 , and a cathode Pt loading of 0.5 mg / cm 2 . At a current density of 2 A / cm 2 under the test condition of 60 °C, the electrolysis potential was 1.858 V. At a current density of 2 A / cm 2 under the test condition of 80 °C, the electrolysis potential was only 1.785 V, showing good membrane electrode device performance.

[0071] Example 7

[0072] The difference between this example and Example 6 is that in Example 6, the carbamide was adjusted from 6 mmol to 1.5 mol, and the remaining steps remained unchanged. The yield of the iridium oxide catalyst was 97.8%. The iridium oxide catalyst obtained in this example was tested according to the membrane electrode test method of Example 1, with an anode iridium loading of 0.6 mg / cm 2 , and a cathode Pt loading of 0.5 mg / cm 2 . At a current density of 2 A / cm 2 under the test condition of 60 °C, the electrolysis potential was 1.913 V. At a current density of 2 A / cm 2 under the test condition of 80 °C, the electrolysis potential was only 1.855 V, showing good membrane electrode device performance.

[0073] 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 defined 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. An iridium oxide catalyst, characterized in that The iridium oxide catalyst is a nanowire structure with a diameter of 1-10 nm and an aspect ratio of 10-2000.

2. A method for preparing an iridium oxide catalyst, characterized in that: The following steps are involved: The iridium source, the auxiliary ligand and the reaction aid are added into water and dissolved evenly, and after heating for reaction, the solid is collected and washed to obtain a pre-product; The pre-product is subjected to heat treatment to obtain the iridium oxide catalyst; The iridium oxide catalyst is a nanowire structure with a diameter of 1-10 nm and an aspect ratio of 5-2000.

3. The preparation method of iridium oxide catalyst according to claim 2, characterized in that, The iridium source is selected from one or a combination of two or more of iridium trichloride, iridium tetrachloride, iridium acetylacetonate, chloroiridic acid and its salts, and iridium acetate.

4. The preparation method of iridium oxide catalyst according to claim 2, characterized in that, The auxiliary ligand is selected from one or a combination of two or more of amide organic compounds and organic amine compounds.

5. The preparation method of iridium oxide catalyst according to claim 2, characterized in that, The reaction aid is selected from one or a combination of two or more nitrates.

6. The method for preparing an iridium oxide catalyst according to claim 2, wherein The molar ratio of the iridium source to the auxiliary ligand is 0.01-1:

1.

7. The method for preparing an iridium oxide catalyst according to claim 2, wherein The molar ratio of the iridium source to the reaction aid is 0.001-1:

1.

8. The method for preparing an iridium oxide catalyst according to claim 2, wherein The reaction temperature of the heating reaction is 70-120°C.

9. The method for preparing an iridium oxide catalyst according to claim 2, wherein: The temperature of the heat treatment is 350-600°C.

10. Use of the iridium oxide catalyst according to claim 1 or the iridium oxide catalyst obtained by the preparation method of the iridium oxide catalyst according to any one of claims 2 to 9, characterized in that: As anode catalyst for electrocatalytic water splitting or anti-reversal catalyst for fuel cells.

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