A bimetallic oxide catalyst and its preparation method and application

Abstract

The present invention provides a bimetallic oxide catalyst, a preparation method, and an application thereof, relating to the technical field of anode materials for water electrolysis. The bimetallic oxide catalyst provided by the present invention comprises a CeO2 substrate and an IrO2 active component disposed on the surface of the CeO2 substrate. The CeO2-IrO2 bimetallic oxide catalyst designed by the present invention is used as a proton exchange membrane (PEM) water electrolysis anode and has higher catalytic activity and mass activity than pure IrO2 catalyst, while also having good stability and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of anode materials for water electrolysis, and in particular to a bimetallic oxide catalyst and a preparation method and application thereof. Background Art

[0002] Hydrogen energy, as the cleanest energy source with the greatest potential to replace fossil fuels, has attracted widespread attention. Proton exchange membrane (PEM) water electrolysis devices are an efficient and environmentally friendly way to produce hydrogen. The oxygen evolution reaction (OER) occurring on the anode side is a key catalytic process in PEM water electrolysis. However, because OER involves the transfer of four electrons, it typically requires a very high overpotential to obtain a reaction current sufficient for practical applications. Furthermore, OER produces a large amount of hydrogen ions, causing the anode catalyst to corrode and fail in the acidic electrolyte, or even fall off. Therefore, the development of anode catalysts with high catalytic activity and high stability has been the core of PEM water electrolysis technology research in recent years.

[0003] Currently, IrO2 catalyst has become the most widely used anode in PEM water electrolysis under acidic electrolyte conditions. However, in practical applications, the following problems still need to be solved: (1) the catalytic activity of pure IrO2 is not high enough, and there is room for improvement; (2) the loading of pure IrO2 on the proton exchange membrane is generally as high as 2 mg / cm 2 , resulting in excessively high costs for hydrogen production by water electrolysis; (3) Pure IrO2 particles adhere to the proton exchange membrane, which is accompanied by agglomeration, and the active sites are not fully exposed, resulting in a decrease in the mass activity of IrO2; (4) The bonding force between pure IrO2 particles and the proton exchange membrane is relatively weak, and they are easily detached under the action of acidic environments and bubbles generated by oxygen evolution. Summary of the Invention

[0004] The purpose of the present invention is to provide a bimetallic oxide catalyst and its preparation method and application. The bimetallic oxide catalyst provided by the present invention has high catalytic activity and mass activity when used as a PEM water electrolysis anode, and has good stability and low cost.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a bimetallic oxide catalyst comprising a CeO2 substrate and an IrO2 active component arranged on the surface of the CeO2 substrate.

[0007] Preferably, the IrO2 active component and the CeO2 substrate are connected via a heterojunction.

[0008] Preferably, the coverage of the IrO2 active component on the surface of the CeO2 substrate is 10-90%; the mass ratio of the IrO2 active component to the CeO2 substrate is 0.1-10:100.

[0009] Preferably, the IrO2 active component is in a granular form, and the diameter of the IrO2 active component is 10 to 40 nm.

[0010] Preferably, the CeO2 substrate is in the form of a thin sheet, and the area of the CeO2 substrate is 100 to 1,000,000 nm. 2 , the thickness of the CeO2 substrate is 30 to 100 nm.

[0011] The present invention provides a method for preparing the bimetallic oxide catalyst described in the above technical solution, comprising the following steps:

[0012] (1) CeO2 flakes were prepared on the surface of carbon paper by anodic electrodeposition;

[0013] (2) IrO2 particles were prepared on the surface of carbon paper loaded with CeO2 flakes by anodic electrodeposition;

[0014] (3) calcining the carbon paper loaded with CeO2 flakes and IrO2 particles to obtain the bimetallic oxide catalyst.

[0015] Preferably, the step (1) of preparing CeO2 flakes on the surface of carbon paper by anodic electrodeposition includes: using carbon paper as an anode and an aqueous solution of trivalent cerium salt, stabilizer and CH3CH2OH as an electrolyte solution to perform electrochemical oxidation to prepare CeO2 flakes on the surface of carbon paper.

[0016] Preferably, the step (2) of preparing IrO2 particles on the surface of carbon paper loaded with CeO2 flakes by using anodic electrodeposition includes: using carbon paper loaded with CeO2 flakes as an anode, using an aqueous solution of trivalent iridium salt and a stabilizer as an electrolyte solution, performing electrochemical oxidation, and preparing IrO2 particles on the surface of carbon paper loaded with CeO2 flakes.

[0017] Preferably, the calcination temperature in step (3) is 500-800° C.; and the calcination time is more than 2 hours.

[0018] The present invention provides the use of the bimetallic oxide catalyst described in the above technical solution or the bimetallic oxide catalyst prepared by the preparation method described in the above technical solution in the anode of water electrolysis.

[0019] The present invention provides a bimetallic oxide catalyst comprising a CeO2 substrate and an IrO2 active component disposed on the surface of the CeO2 substrate. The present invention constructs a CeO2-IrO2 bimetallic oxide by introducing CeO2 into IrO2, thereby optimizing the inherent electronic structure of the IrO2 active site while reducing the amount of precious metal Ir. Compared with pure IrO2 catalysts, the CeO2-IrO2 bimetallic oxide catalyst provided by the present invention has lower cost and higher catalytic activity for OER. In addition, the CeO2-IrO2 bimetallic oxide designed by the present invention forms a heterojunction, which will facilitate anchoring the IrO2 active component on the surface of the CeO2 substrate and promoting discrete and uniform distribution of the IrO2 active component. Compared with pure IrO2 catalysts, the stability performance and mass activity of the CeO2-IrO2 bimetallic oxide catalyst provided by the present invention are improved.

[0020] The present invention provides a method for preparing the bimetallic oxide catalyst described in the above technical solution. Compared with common preparation methods of precious metal oxide catalysts such as the Adams melting method, thermal decomposition method and hydrothermal method, the anodic electrodeposition method adopted in the present invention can simply and controllably prepare a CeO2-IrO2 bimetallic oxide catalyst with a heterojunction.

[0021] In the present invention, when CeO2-IrO2 bimetallic oxide catalyst is used as the anode of PEM water electrolysis, it reaches 10mA·cm compared with the commercial pure IrO2 catalyst. -2 The required overpotential was reduced by 20-120 mV, and the mass activity was increased by 1-7 mA·μg Ir -1 , the stability performance is enhanced by at least 2 times, while the amount of precious metal Ir is reduced by more than 20%. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a SEM image of the carbon paper in Example 1 of the present invention at a scale of 500 nm (the inset is a SEM image at a scale of 50 nm);

[0023] Figure 2 This is a SEM image of the carbon paper loaded with CeO2 flakes prepared in Example 1 of the present invention at a scale of 500 nm (the inset is a SEM image at a scale of 50 nm);

[0024] Figure 3 SEM image of the carbon paper loaded with CeO2 flakes and IrO2 particles prepared in Example 1 of the present invention at a scale of 500 nm (the inset is an SEM image at a scale of 50 nm). DETAILED DESCRIPTION

[0025] The present invention provides a bimetallic oxide catalyst comprising a CeO2 substrate and an IrO2 active component arranged on the surface of the CeO2 substrate.

[0026] The bimetallic oxide catalyst provided by the present invention includes a CeO2 substrate. In the present invention, the CeO2 substrate is preferably in the form of a thin sheet, and the area of the CeO2 substrate is preferably 100 to 1,000,000 nm. 2 , more preferably 250000~400000nm 2 ; The thickness of the CeO2 substrate is preferably 30 to 100 nm, more preferably 30 to 60 nm.

[0027] The bimetallic oxide catalyst provided herein includes an IrO2 active component disposed on the surface of a CeO2 substrate. In the present invention, the IrO2 active component and the CeO2 substrate are preferably connected via a heterojunction. In the present invention, the IrO2 active component is preferably in a granular form, and the diameter of the IrO2 active component is preferably 10 to 40 nm, more preferably 20 to 30 nm.

[0028] In the present invention, the coverage of the IrO2 active component on the surface of the CeO2 substrate is preferably 10-90%, more preferably 40-80%, and further preferably 60%; the mass ratio of the IrO2 active component to the CeO2 substrate is preferably 0.1-10:100, more preferably 0.5-8:100, and further preferably 3:100.

[0029] The present invention provides a method for preparing the bimetallic oxide catalyst described in the above technical solution, comprising the following steps:

[0030] (1) CeO2 flakes were prepared on the surface of carbon paper by anodic electrodeposition;

[0031] (2) IrO2 particles were prepared on the surface of carbon paper loaded with CeO2 flakes by anodic electrodeposition;

[0032] (3) calcining the carbon paper loaded with CeO2 flakes and IrO2 particles to obtain the bimetallic oxide catalyst.

[0033] The present invention utilizes anodic electrodeposition to prepare CeO2 flakes on the surface of carbon paper. Prior to preparing the CeO2 flakes, the present invention preferably further comprises pre-treating the carbon paper. In the present invention, the pre-treatment preferably includes sequentially performing acetone washing, ethanol washing, acid washing, water washing, and drying. In the present invention, the acetone washing is preferably performed using an acetone solution with a purity of 99 wt% or greater; the ethanol washing is preferably performed using an ethanol solution with a purity of 99 wt% or greater. In the present invention, the hydrogen ion concentration of the acid washing solution is preferably 0.01 to 1 mol / L, more preferably 0.1 mol / L; the acid washing solution is preferably an aqueous HCl solution. In the present invention, the acetone washing, ethanol washing, and acid washing are preferably ultrasonic washing; the duration of each ultrasonic washing is preferably 20 minutes or longer, more preferably 30 minutes. In the present invention, the water washing is preferably deionized water washing. Water washing to neutrality is preferred. The present invention ensures complete removal of impurities from the carbon paper surface by sequentially performing acetone washing, ethanol washing, acid washing, and water washing.

[0034] In the present invention, the method of preparing CeO2 flakes on the surface of carbon paper by anodic electrodeposition preferably includes: using carbon paper as an anode, using an aqueous solution of a trivalent cerium salt, a stabilizer and CH3CH2OH as an electrolyte solution, and performing electrochemical oxidation to prepare CeO2 flakes on the surface of carbon paper. In the present invention, the trivalent cerium salt preferably includes Ce(NO3)3 or CeCl3, more preferably Ce(NO3)3. In the present invention, the stabilizer preferably includes acetic acid or acetate; the acetate preferably includes CH3COONH4 or CH3COONa, more preferably CH3COONH4. In the present invention, the NH4 + It can refine the grains of CeO2 thin films.

[0035] In the present invention, CH3CH2OH acts as an additive in the electrolyte solution, which can improve the density of the CeO2 film.

[0036] In the present invention, the concentration of the trivalent cerium salt in the electrolyte solution is preferably 0.01 to 0.1 mol / L, more preferably 0.05 mol / L; the concentration of the stabilizer is preferably 0.01 to 1 mol / L, more preferably 0.1 mol / L; and the volume percentage of CH3CH2OH in the electrolyte solution is preferably 10 to 40%, more preferably 10 to 30%. During the electrochemical oxidation, the temperature and pH of the electrolyte solution are preferably maintained constant. During the electrochemical oxidation, the temperature of the electrolyte solution is preferably 30 to 70°C, more preferably 50 to 60°C; the pH of the electrolyte solution is preferably 5 to 7, more preferably 6.2. During the electrochemical oxidation, the potential of the electrochemical oxidation is preferably 0.8 to 1.6 V, more preferably 1.2 to 1.4 V; and the duration of the electrochemical oxidation is preferably 10 to 60 min, more preferably 30 to 40 min. During the electrochemical oxidation, the cathode is preferably graphite or platinum sheet.

[0037] After obtaining the carbon paper loaded with CeO2 flakes, the present invention adopts an anodic electrodeposition method to prepare IrO2 particles on the surface of the carbon paper loaded with CeO2 flakes.

[0038] In the present invention, the method of preparing IrO2 particles on the surface of carbon paper loaded with CeO2 flakes by anodic electrodeposition preferably includes: using the carbon paper loaded with CeO2 flakes as the anode and an aqueous solution of a trivalent iridium salt and a stabilizer as the electrolyte solution to perform electrochemical oxidation to prepare IrO2 particles on the surface of the carbon paper loaded with CeO2 flakes. In the present invention, the trivalent iridium salt preferably includes IrCl3 or iridium sulfate, more preferably IrCl3. In the present invention, the stabilizer preferably includes acetic acid or acetate; the acetate preferably includes CH3COONH4 or CH3COONa, more preferably CH3COONH4.

[0039] In the present invention, the concentration of the trivalent iridium salt in the electrolyte solution is preferably 0.001 to 0.1 mol / L, more preferably 0.004 mol / L; the concentration of the stabilizer is preferably 0.01 to 0.1 mol / L, more preferably 0.02 mol / L. In the present invention, when performing the electrochemical oxidation, the pH value of the electrolyte solution is preferably kept constant at room temperature. In the present invention, the pH value of the electrolyte solution is preferably 9 to 12, more preferably 10.2 to 11. In the present invention, the potential of the electrochemical oxidation is preferably 0.6 to 1.0 V, more preferably 0.8 V; the time of the electrochemical oxidation is preferably 5 to 30 min, more preferably 15 to 20 min. In the present invention, when performing the electrochemical oxidation, the cathode is preferably graphite or platinum sheet.

[0040] After obtaining the carbon paper loaded with CeO2 flakes and IrO2 particles, the present invention calcines the carbon paper loaded with CeO2 flakes and IrO2 particles to obtain the bimetallic oxide catalyst. In the present invention, the calcination is preferably performed in a high-temperature furnace. In the present invention, the calcination temperature is preferably 500-800°C, more preferably 600-700°C; the calcination time is preferably at least 2 hours, more preferably 4 hours. The present invention calcines the carbon paper loaded with CeO2 flakes and IrO2 particles at a high temperature to ensure complete decarburization.

[0041] The present invention provides the use of the bimetallic oxide catalyst described in the above technical solution or the bimetallic oxide catalyst prepared by the preparation method described in the above technical solution in a water electrolysis anode, preferably used in a proton exchange membrane (PEM) water electrolysis anode.

[0042] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] Example 1

[0044] Pretreatment of carbon paper: The carbon paper was ultrasonically cleaned in a 99.9 wt% acetone solution, a 99.9 wt% ethanol solution, and a 0.1 mol / L HCl solution for 30 min, respectively. Finally, the carbon paper was rinsed with deionized water and dried thoroughly to obtain the pretreated carbon paper, which was then stored in a 99.9 wt% acetone solution until use.

[0045] Preparation of CeO2 flakes: An aqueous solution containing 0.05 mol / L Ce(NO3)3, 0.1 mol / L CH3COONH4 and 10% (volume percentage) CH3CH2OH was prepared as the electrolyte solution in an electrolytic cell. Pretreated carbon paper was used as the anode and a platinum sheet was used as the cathode. The temperature of the electrolyte solution was maintained at 50°C and the pH value was 6.2. Electrochemical oxidation was performed at a potential of 1.2 V for 30 minutes to obtain CeO2 flakes on the surface of the carbon paper.

[0046] Preparation of IrO2 particles: An aqueous solution containing 0.004 mol / L IrCl3 and 0.02 mol / L CH3COONH4 was prepared as the electrolyte solution in an electrolytic cell. Carbon paper loaded with CeO2 flakes was used as the anode and a platinum sheet was used as the cathode. The pH value of the electrolyte solution was maintained at 10.2 at room temperature. Electrochemical oxidation was performed at a potential of 0.8 V for 15 minutes to obtain IrO2 particles on the surface of the carbon paper loaded with CeO2 flakes.

[0047] Calcination treatment at high temperature: The carbon paper loaded with CeO2 flakes and IrO2 particles was placed in a furnace and calcined at 600°C for 4 hours to obtain a bimetallic oxide catalyst.

[0048] In the bimetallic oxide catalyst prepared in this embodiment, a heterojunction is formed between the CeO2 substrate and the IrO2 active component; the coverage of the IrO2 active component on the surface of the CeO2 substrate is 60%; the mass ratio of the IrO2 active component to the CeO2 substrate is 3:100; the IrO2 active component is in the form of particles with a diameter of 20 to 30 nm; the CeO2 substrate is in the form of flakes with an area of 250,000 nm 2 , the thickness of the thin film is 30nm.

[0049] When the bimetallic oxide catalyst prepared in this example is used as the anode of PEM water electrolysis, compared with the commercial pure IrO2 catalyst (overpotential: 350mV, mass activity: 0.6mA·μg Ir -1 , Stability: 40h, Amount of precious metal Ir: 2mg / cm 2 ), which reaches 10 mA·cm -2 The overpotential required for the current density was reduced by 130 mV; its mass activity at an overpotential of 300 mV was increased by 6.4 mA·μg Ir -1 ; At 10mA·cm -2 The service life under the current density is 200h, that is, the stability performance is enhanced by 5 times; the amount of precious metal Ir added is 0.8mg / cm 2 , significantly reducing the amount of precious metal Ir used and reducing costs.

[0050] The SEM image of the carbon paper used in this embodiment is as follows Figure 1 As shown in FIG, when the carbon paper is magnified from a 500 nm scale to a 50 nm scale, it can be observed that the microscopic morphology of the carbon paper is a vermicular interlaced structure.

[0051] The SEM image of the carbon paper loaded with CeO2 flakes prepared in this example is as follows: Figure 2 As shown, it can be seen that CeO2 is in the form of thin flakes and is evenly distributed on the carbon paper. When the carbon paper loaded with CeO2 flakes is enlarged from the 500nm scale to the 50nm scale, it can be observed that CeO2 has good crystallinity.

[0052] The SEM image of the carbon paper loaded with CeO2 flakes and IrO2 particles prepared in this example is as follows: Figure 3As shown in the figure, at the 500nm scale, some discretely distributed flakes can be observed. When the scale is magnified to 50nm, some extremely fine particles can be observed distributed on the flakes. Figure 2 By comparison, the flakes correspond to CeO2 and the granular materials correspond to IrO2.

[0053] Example 2

[0054] Pretreatment of carbon paper: The carbon paper was ultrasonically cleaned in a 99.9 wt% acetone solution, a 99.9 wt% ethanol solution, and a 0.1 mol / L HCl solution for 30 min, respectively. Finally, the carbon paper was rinsed with deionized water and dried thoroughly to obtain the pretreated carbon paper, which was then stored in a 99.9 wt% acetone solution until use.

[0055] Preparation of CeO2 flakes: An aqueous solution containing 0.05 mol / L Ce(NO3)3, 0.1 mol / L CH3COONH4 and 10% (volume percentage) CH3CH2OH was prepared as the electrolyte solution in an electrolytic cell. Pretreated carbon paper was used as the anode and a platinum sheet was used as the cathode. The temperature of the electrolyte solution was maintained at 50°C and the pH value was 6.2. Electrochemical oxidation was performed at a potential of 1.4 V for 60 minutes to obtain CeO2 flakes on the surface of the carbon paper.

[0056] Preparation of IrO2 particles: An aqueous solution containing 0.004 mol / L IrCl3 and 0.02 mol / L CH3COONH4 was prepared as the electrolyte solution in an electrolytic cell. Carbon paper loaded with CeO2 flakes was used as the anode and a platinum sheet was used as the cathode. The pH value of the electrolyte solution was maintained at 10.2 at room temperature. Electrochemical oxidation was performed at a potential of 0.8 V for 15 minutes to obtain IrO2 particles on the surface of the carbon paper loaded with CeO2 flakes.

[0057] Calcination treatment at high temperature: The carbon paper loaded with CeO2 flakes and IrO2 particles was placed in a furnace and calcined at 600°C for 4 hours to obtain a bimetallic oxide catalyst.

[0058] In the bimetallic oxide catalyst prepared in this embodiment, a heterojunction is formed between the CeO2 substrate and the IrO2 active component; the coverage of the IrO2 active component on the surface of the CeO2 substrate is 40%; the mass ratio of the IrO2 active component to the CeO2 substrate is 0.5:100; the IrO2 active component is in the form of particles with a diameter of 20 to 30 nm; the CeO2 substrate is in the form of flakes with an area of 400,000 nm 2 , the thickness of the thin film is 60nm.

[0059] When the bimetallic oxide catalyst prepared in this example is used as the anode of PEM water electrolysis, compared with the commercial pure IrO2 catalyst (overpotential: 350mV, mass activity: 0.6mA·μg Ir -1 , Stability: 40h, Amount of precious metal Ir: 2mg / cm 2 ), which reaches 10 mA·cm -2 The overpotential required for the current density was reduced by 100 mV; its mass activity at an overpotential of 300 mV increased by 1.8 mA·μg Ir -1 ; At 10mA·cm -2 The service life under the current density is 120h, that is, the stability performance is enhanced by 3 times; the amount of precious metal Ir added is 0.8mg / cm 2 , significantly reducing the amount of precious metal Ir used and reducing costs.

[0060] Example 3

[0061] Pretreatment of carbon paper: The carbon paper was ultrasonically cleaned in a 99.9 wt% acetone solution, a 99.9 wt% ethanol solution, and a 0.1 mol / L HCl solution for 30 min, respectively. Finally, the carbon paper was rinsed with deionized water and dried thoroughly to obtain the pretreated carbon paper, which was then stored in a 99.9 wt% acetone solution until use.

[0062] Preparation of CeO2 flakes: An aqueous solution containing 0.05 mol / L Ce(NO3)3, 0.1 mol / L CH3COONH4 and 10% (volume percentage) CH3CH2OH was prepared as the electrolyte solution in an electrolytic cell. Pretreated carbon paper was used as the anode and a platinum sheet was used as the cathode. The temperature of the electrolyte solution was maintained at 50°C and the pH value was 6.2. Electrochemical oxidation was performed at a potential of 1.2 V for 30 minutes to obtain CeO2 flakes on the surface of the carbon paper.

[0063] Preparation of IrO2 particles: An aqueous solution containing 0.004 mol / L IrCl3 and 0.02 mol / L CH3COONH4 was prepared as the electrolyte solution in an electrolytic cell. Carbon paper loaded with CeO2 flakes was used as the anode and a platinum sheet was used as the cathode. The pH value of the electrolyte solution was maintained at 10.2 at room temperature. Electrochemical oxidation was performed at a potential of 0.8 V for 30 minutes to obtain IrO2 particles on the surface of the carbon paper loaded with CeO2 flakes.

[0064] Calcination treatment at high temperature: The carbon paper loaded with CeO2 flakes and IrO2 particles was placed in a furnace and calcined at 600°C for 4 hours to obtain a bimetallic oxide catalyst.

[0065] In the bimetallic oxide catalyst prepared in this embodiment, a heterojunction is formed between the CeO2 substrate and the IrO2 active component; the coverage of the IrO2 active component on the surface of the CeO2 substrate is 80%; the mass ratio of the IrO2 active component to the CeO2 substrate is 8:100; the IrO2 active component is in the form of particles with a diameter of 30 to 40 nm; the CeO2 substrate is in the form of flakes with an area of 250,000 nm 2 , the thickness of the thin film is 30nm.

[0066] When the bimetallic oxide catalyst prepared in this example is used as the anode of PEM water electrolysis, compared with the commercial pure IrO2 catalyst (overpotential: 350mV, mass activity: 0.6mA·μg Ir -1 , Stability: 40h, Amount of precious metal Ir: 2mg / cm 2 ), which reaches 10 mA·cm -2 The overpotential required for the current density was reduced by 130 mV; its mass activity at an overpotential of 300 mV was increased by 3.0 mA·μg Ir -1 ; At 10mA·cm -2 The service life under the current density is 60h, that is, the stability performance is enhanced by 1.5 times; the amount of precious metal Ir added is 1.6mg / cm 2 , reducing the amount of precious metal Ir used and reducing costs.

[0067] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A bimetallic oxide catalyst, characterized in that: It includes a CeO2 substrate and an IrO2 active component arranged on the surface of the CeO2 substrate; the IrO2 active component and the CeO2 substrate are connected through a heterojunction; the coverage rate of the IrO2 active component on the surface of the CeO2 substrate is 40-80%; the IrO2 active component is granular, and the diameter of the IrO2 active component is 10-40nm; the CeO2 substrate is in the form of a thin sheet.

2. The bimetallic oxide catalyst according to claim 1, characterized in that The mass ratio of the IrO2 active component to the CeO2 substrate is 0.1-10:

100.

3. The bimetallic oxide catalyst according to claim 1, characterized in that The area of the CeO2 substrate is 100 to 1,000,000 nm. 2 , the thickness of the CeO2 substrate is 30 to 100 nm.

4. The method for preparing the bimetallic oxide catalyst according to any one of claims 1 to 3, comprising the following steps: (1) CeO2 flakes were prepared on the surface of carbon paper by anodic electrodeposition; (2) IrO2 particles were prepared on the surface of carbon paper loaded with CeO2 flakes by anodic electrodeposition; (3) calcining the carbon paper loaded with CeO2 flakes and IrO2 particles to obtain the bimetallic oxide catalyst.

5. The preparation method according to claim 4, characterized in that The step (1) of preparing CeO2 flakes on the surface of carbon paper by anodic electrodeposition includes: using carbon paper as an anode and an aqueous solution of trivalent cerium salt, stabilizer and CH3CH2OH as an electrolyte solution to perform electrochemical oxidation to prepare CeO2 flakes on the surface of carbon paper.

6. The preparation method according to claim 4, characterized in that The step (2) of preparing IrO2 particles on the surface of carbon paper loaded with CeO2 flakes by anodic electrodeposition includes: using carbon paper loaded with CeO2 flakes as an anode, using an aqueous solution of trivalent iridium salt and a stabilizer as an electrolyte solution, and performing electrochemical oxidation to prepare IrO2 particles on the surface of carbon paper loaded with CeO2 flakes.

7. The preparation method according to claim 4, characterized in that The calcination temperature in step (3) is 500-800° C.; the calcination time is more than 2 hours.

8. Use of the bimetallic oxide catalyst according to any one of claims 1 to 3 or the bimetallic oxide catalyst prepared by the preparation method according to any one of claims 4 to 7 in the anode of water electrolysis.

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