A defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst and its preparation method and application

Abstract

The present invention provides a defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst, its preparation method, and application. The method comprises sequentially preparing a carbon skeleton, a defective carbon-nitrogen skeleton, and a defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst, ultimately obtaining a defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst. In the present invention, the defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst can effectively improve the efficiency and performance of the anode reaction for hydrogen production from water electrolysis due to its high specific surface area, rich porous structure, prominent electron-donating structure, and excellent electrical conductivity.

Description

Technical Field

[0001] The present invention relates to a new energy technology for hydrogen production by electrolysis of water, and in particular to a defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst, and a preparation method and application thereof. Background Art

[0002] In recent years, to mitigate the greenhouse effect and energy shortages, the world has vigorously developed new energy and a low-carbon economy. Wind and solar power are gaining increasing attention as a new energy source. However, the fluctuations and poor stability of wind and solar power lead to waste. New energy hydrogen production technology, characterized by zero carbon emissions, zero pollution, and low energy consumption, can absorb wind and solar power and reduce waste. The membrane electrode, as the core of the proton exchange membrane water electrolysis system, fundamentally determines the system's performance, efficiency, lifespan, and cost. Because the activation overpotential of the oxygen evolution reaction on the anode side is much higher than that of the hydrogen evolution reaction at the cathode, improving the properties of the anode electrocatalyst is crucial. Anode catalysts primarily focus on iridium and rubidium-related materials, taking into account factors such as antioxidant properties, corrosion resistance, and stability. These two precious metals are scarce in China and are expensive. Developing low-iridium catalyst systems and loading structures to improve their performance is particularly important.

[0003] In recent years, researchers both domestically and internationally have conducted extensive research on anode catalysts for hydrogen production via proton exchange membrane electrolysis (PEM). To achieve rapid electron-proton coupling reactions, common approaches include constructing iridium-based precious metal nanoparticles, alloying precious metals with copper, cobalt, and other materials, or constructing precious metal oxides or binary or ternary mixed oxides. Catalyst supports include carbon, nitrogen, or carbide substrates. Currently, substrates with sufficient sustainability, specific surface area, and conductivity are difficult to achieve.

[0004] In research, single transition metal atoms have shown advantages such as high atomic utilization, good stability, and excellent electrochemical performance, thereby improving reaction efficiency. Experiments have shown that the synergistic catalysis of iridium and nickel atoms reduces the energy barrier for the conversion of H2O to O2, especially the energy barrier for the elementary reaction from *OH to *O, and improves the reaction kinetic parameters. Iron improves the conductivity of the system and synergistically reduces the overpotential of the anodic reaction with iridium and nickel. During the anodic oxygen evolution reaction, defective carbon and nitrogen materials, due to their special delocalized π bond structure, act as electron donors, providing more charges and nucleation sites for the catalytic reaction of iridium. Therefore, the use of defective carbon and nitrogen skeletons to support single-atom iridium / iron-nickel catalysts to catalyze anodic oxygen evolution in water electrolysis can effectively improve the efficiency and performance of hydrogen production from water electrolysis, and has strong application prospects in the field of hydrogen production from water electrolysis. However, no related research reports have been found so far. Summary of the Invention

[0005] In order to overcome the technical problems of the prior art, the present invention provides a defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst and a preparation method and application thereof.

[0006] As one aspect of the present invention, the present invention provides a method for preparing a defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst, which comprises the following steps:

[0007] The pretreated dicyandiamide is heated in a nitrogen atmosphere, cooled, and then heated again in an air atmosphere to obtain a carbon-nitrogen skeleton;

[0008] The carbon-nitrogen skeleton, lithium chloride, and isopropanol are mixed and ball-milled, and the mixed slurry is dried and then heated to obtain a powder; wherein the mass volume ratio of the carbon-nitrogen skeleton, lithium chloride powder, and isopropanol is (0.135-0.165 g): (1.76-2.00 g): (9.5-10.5 mL);

[0009] The powdered material is dispersed in a sulfuric acid solution and dried to obtain a defective carbon-nitrogen skeleton;

[0010] The defective framework material, iridium chloride, α-D-glucose and water are uniformly mixed and ultrasonicated, and a solid product is obtained by centrifugation. After drying, the solid product is heated under a nitrogen atmosphere to obtain a defective carbon-nitrogen framework-supported single-atom iridium catalyst; wherein the mass volume ratio of the defective framework material, iridium chloride, α-D-glucose and water is (0.725-0.775 g): (0.54-0.58 g): (14.03-14.21 g): (55-65 mL);

[0011] The defective carbon-nitrogen skeleton-supported single-atom iridium catalyst is dispersed in N,N-dimethylformamide and ultrasonicated, a mixture of nickel phthalocyanine and iron phthalocyanine is added, stirred and centrifuged, and the obtained solid is dried to obtain the defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst.

[0012] Preferably, when preparing the carbon-nitrogen skeleton, the heating rate of dicyandiamide at 550° C. is 2-3° C. / min.

[0013] Preferably, when preparing the defective carbon-nitrogen skeleton, the ball milling speed is 250 to 300 rpm / min.

[0014] Preferably, when preparing the defective carbon-nitrogen skeleton-supported single-atom iridium catalyst, it is necessary to heat from room temperature to 800° C. and maintain it for 2 hours, with a heating rate of 5 to 6° C. / min.

[0015] Preferably, the mass ratio of nickel phthalocyanine to iron phthalocyanine is 5:1 to 3:1.

[0016] As one aspect of the present invention, the present invention provides a defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst.

[0017] As one aspect of the present invention, the present invention provides an application of a defective carbon-nitrogen skeleton-loaded single-atom iridium / iron-nickel catalyst, which is: using 60wt% platinum / carbon as a cathode catalyst, a defective carbon-nitrogen skeleton-loaded single-atom iridium / iron-nickel catalyst as an anode catalyst, and Nafion 117 as a proton exchange membrane to prepare a membrane electrode, and constructing a single proton exchange membrane electrolyzer from the inside to the outside in the order of membrane electrode, porous current collector and bipolar plate.

[0018] Preferably, the platinum and anode catalyst loadings are 0.4 to 0.5 mg / cm 2 and 1.25-1.35 mg / cm 2 The active area of ​​the cathode and anode is controlled at 3.6-4 cm 2 .

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] In the present invention, the defective carbon-nitrogen skeleton-loaded single-atom iridium / iron-nickel catalyst can effectively improve the efficiency and performance of the anode reaction of hydrogen production by electrolysis of water due to its high specific surface area, rich porous structure, outstanding electron-donating structure and excellent electrical conductivity. Defective carbon-nitrogen materials, as electron donors, provide more charges and nucleation sites for the catalytic reaction of iridium due to their special delocalized π bond structure. The synergistic catalysis of iridium and nickel atoms reduces the energy barrier of the anode oxygen evolution reaction, especially the energy barrier of the highest potential *OH to *O elementary reaction, and improves the reaction kinetic parameters. Iron improves the electrical conductivity of the system and synergistically acts with iridium and nickel to reduce the overpotential of the anode reaction. The overpotential achieved by existing iridium / transition metal catalysts is generally 200-300mV@10mA / cm 2 , and the development of these catalysts is almost limited to element doping, etc., and the positive feedback catalysis between transition metals has not been improved. In addition, the existing catalysts loaded with C, N or carbide substrates are difficult to meet the requirements due to sustainability, specific surface area, and conductivity, and the catalytic performance needs to be strengthened. The present invention significantly improves the above-mentioned problems of existing catalysts through the method of defective carbon-nitrogen skeleton coupling and iridium-nickel-iron atomic synergistic catalysis, and provides a large number of active sites and pore structures. The anode reaction catalyst prepared by the present invention reduces the overpotential of the anode oxygen evolution reaction by 21%, and the iridium mass activity is reduced from 105 to 110 A / g Ir Increased to 932-956A / g Ir , the catalytic performance is improved by 5 to 6 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the technical roadmap of the present invention. DETAILED DESCRIPTION

[0022] The dicyandiamide, lithium chloride, isopropyl alcohol, sulfuric acid, iridium chloride, α-D-glucose, NN-dimethylformamide, nickel phthalocyanine and iron phthalocyanine used in the present invention were purchased from China National Pharmaceutical Group Chemical Reagent Co., Ltd.; Nafion proton exchange membrane was purchased from DuPont.

[0023] Example 1

[0024] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0025] like Figure 1 As shown, the preparation of the defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst and the catalytic oxygen evolution reaction at the anode of water electrolysis specifically include the following steps:

[0026] (1) First, a dicyandiamide aqueous solution (20 wt%) was freeze-dried for 24 h to obtain assembled dicyandiamide. Subsequently, the assembled dicyandiamide was treated in a 550°C vacuum tube furnace under a nitrogen atmosphere for 2 h. After cooling to room temperature, the resulting product was heated at 500°C in an air atmosphere for 1 h to obtain a carbon-nitrogen skeleton. This carbon-nitrogen skeleton is a graphene-like structure with a nitrogen-carbon ratio of 1.28 to 1.35 and a specific surface area of ​​25 to 30 m 2 / g, and the conductivity is 3.8~4.4×10 -5 The assembled dicyandiamide was treated at 550°C at a heating rate of 2-3°C / min.

[0027] (2) Take 0.15g of the carbon-nitrogen skeleton in step (1), 1.88g of lithium chloride powder and 10mL of isopropanol and add them to a ball mill for processing for 1.5h. Then place the mixed slurry in a 60℃ vacuum oven to dry, then place it in an alumina crucible and heat it in a 550℃ vacuum tube furnace for 2h. After that, disperse the treated powder into a 5wt% sulfuric acid solution. Rinse the mixture with deionized water several times until the pH of the rinse liquid is neutral, and then dry it in a 60℃ vacuum oven to obtain a defective carbon-nitrogen skeleton. This defective carbon-nitrogen skeleton is a graphene-like structure with a nitrogen-carbon ratio of 0.68-0.73 and a specific surface area of ​​420-445m 2 / g, electrical conductivity is 0.093~0.11S / cm. The ball milling speed is 250~300rpm / min.

[0028] (3) 0.75 g of the defective framework material from step (2), 0.56 g of iridium chloride, 14.12 g of α-D-glucose, and 60 mL of deionized water were uniformly mixed and sonicated for 1 h. The mixture was then centrifuged four times with deionized water, and the resulting solid product was dried in an 80°C oven for 18 h.

[0029] (4) The solid product obtained in step (3) was transferred to a vacuum tube furnace filled with nitrogen atmosphere, and heated from room temperature to 800 ° C at a certain heating rate and maintained for 2 hours to obtain a defective carbon-nitrogen skeleton-supported single-atom iridium catalyst. This catalyst has a high thermal conductivity at 1.6 A / cm 2 Under the conditions of 1.79-1.82 V, the iridium mass activity of the catalyst is 750-788 A / g. Ir , ohmic impedance is 36.2~39.9mΩ / cm 2 The heating rate is 5-6°C / min.

[0030] (5) Take 1.25g of the sample obtained in step (4) and disperse it in 110mL of N,N-dimethylformamide and ultrasonicate for 1h. Then disperse 115mg of a mixture of nickel phthalocyanine and iron phthalocyanine into the ultrasonicated liquid and stir it at room temperature for 12h. Finally, the obtained liquid was centrifuged four times with deionized water to obtain a black solid, which was placed in an oven at 60℃ and dried for 12h to obtain a defective carbon nitrogen skeleton supported single atom iridium / iron-nickel catalyst. This catalyst has a high conductivity at 1.6A / cm 2 Under the conditions of , the voltage is 1.53 ~ 1.61V, and the iridium mass activity of the catalyst is 932 ~ 956A / g Ir , ohmic impedance is 15.5~16.8mΩ / cm 2 The mass ratio of nickel phthalocyanine to iron phthalocyanine is 5:1 to 3:1.

[0031] (6) A membrane electrode was prepared using 60wt% platinum / carbon as the cathode catalyst, the sample obtained in step (5) as the anode catalyst, and Nafion 117 as the proton exchange membrane. A single proton exchange membrane electrolyzer was constructed from the inside out in the order of membrane electrode, porous current collector, and bipolar plate. During the anode oxygen evolution reaction, the defective carbon-nitrogen material, due to its special delocalized π bond structure, acts as an electron donor, providing more charges and nucleation sites for the catalytic reaction of iridium. The synergistic catalysis of iridium and nickel atoms reduces the energy barrier for the conversion of H2O to O2, especially the energy barrier for the elementary reaction from *OH to *O, and improves the reaction kinetic parameters. Iron improves the conductivity of the system and synergistically reduces the anode reaction overpotential with iridium and nickel, making 10mA / cm 2 The overpotential is lower than 170mV, which is 21% lower than the overpotential of the existing catalyst anode. The platinum and anode catalyst loadings are 0.4-0.5mg / cm 2 and 1.25-1.35 mg / cm 2 The active area of ​​the cathode and anode is controlled at 3.6-4 cm 2 The treatment temperature and treatment time of the vacuum tube furnace were optimized through multiple experimental measurements, and it was finally determined that the best experimental results were achieved when the treatment temperature in steps 1 and 2 was 550°C, the treatment temperature in step 4 was 800°C, and the treatment time was 2h.

[0032] Example 2

[0033] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0034] like Figure 1 As shown, the preparation of the defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst and the catalytic oxygen evolution reaction at the anode of water electrolysis specifically include the following steps:

[0035] (1) First, a dicyandiamide aqueous solution (20 wt%) was freeze-dried for 24 h to obtain assembled dicyandiamide. Subsequently, the assembled dicyandiamide was treated in a 550°C vacuum tube furnace under a nitrogen atmosphere for 2 h. After cooling to room temperature, the resulting product was heated at 500°C in an air atmosphere for 1 h to obtain a carbon-nitrogen skeleton. This carbon-nitrogen skeleton is a graphene-like structure with a nitrogen-carbon ratio of 1.28 to 1.35 and a specific surface area of ​​25 to 30 m 2 / g, and the conductivity is 3.8~4.4×10 -5 The assembled dicyandiamide was treated at 550°C at a heating rate of 2-3°C / min.

[0036] (2) Take 0.135g of the carbon-nitrogen skeleton in step (1), 2.00g of lithium chloride powder and 9.5mL of isopropanol and add them to a ball mill for processing for 1.5h. Then place the mixed slurry in a 60℃ vacuum oven to dry, then place it in an alumina crucible and heat it in a 550℃ vacuum tube furnace for 2h. After that, disperse the treated powder into a 5wt% sulfuric acid solution. Rinse the mixture with deionized water several times until the pH of the rinse liquid is neutral, and then dry it in a 60℃ vacuum oven to obtain a defective carbon-nitrogen skeleton. This defective carbon-nitrogen skeleton is a graphene-like structure with a nitrogen-carbon ratio of 0.63 to 0.78 and a specific surface area of ​​409 to 420m 2 / g, electrical conductivity is 0.092~0.095S / cm. The ball milling speed is 250~300rpm / min.

[0037] (3) 0.725 g of the defective framework material from step (2), 0.58 g of iridium chloride, 14.03 g of α-D-glucose, and 55 mL of deionized water were uniformly mixed and sonicated for 1 h. The mixture was then centrifuged four times with deionized water, and the resulting solid product was dried in an 80°C oven for 18 h.

[0038] (4) The solid product obtained in step (3) was transferred to a vacuum tube furnace filled with nitrogen atmosphere, and heated from room temperature to 800 ° C at a certain heating rate and maintained for 2 hours to obtain a defective carbon-nitrogen skeleton-supported single-atom iridium catalyst. This catalyst has a high thermal conductivity at 1.6 A / cm 2 Under the conditions of , the voltage is 1.79 ~ 1.82V, and the iridium mass activity of the catalyst is 735 ~ 742A / gIr , ohmic impedance is 40.6~42.2mΩ / cm 2 The heating rate is 5-6°C / min.

[0039] (5) Take 1.25g of the sample obtained in step (4) and disperse it in 110mL of N,N-dimethylformamide and ultrasonicate for 1h. Then disperse 115mg of a mixture of nickel phthalocyanine and iron phthalocyanine into the ultrasonicated liquid and stir it at room temperature for 12h. Finally, the obtained liquid was centrifuged four times with deionized water to obtain a black solid, which was placed in an oven at 60℃ and dried for 12h to obtain a defective carbon nitrogen skeleton supported single atom iridium / iron-nickel catalyst. This catalyst has a high conductivity at 1.6A / cm 2 Under the conditions of 1.53~1.61V, the iridium mass activity of the catalyst is 910~922A / g Ir , ohmic impedance is 17.2~18.3mΩ / cm 2 The mass ratio of nickel phthalocyanine to iron phthalocyanine is 5:1 to 3:1.

[0040] (6) A membrane electrode was prepared using 60wt% platinum / carbon as the cathode catalyst, the sample obtained in step (5) as the anode catalyst, and Nafion 117 as the proton exchange membrane. A single proton exchange membrane electrolyzer was constructed from the inside out in the order of membrane electrode, porous current collector, and bipolar plate. During the anode oxygen evolution reaction, the defective carbon-nitrogen material, due to its special delocalized π bond structure, acts as an electron donor, providing more charges and nucleation sites for the catalytic reaction of iridium. The synergistic catalysis of iridium and nickel atoms reduces the energy barrier for the conversion of H2O to O2, especially the energy barrier for the elementary reaction from *OH to *O, and improves the reaction kinetic parameters. Iron improves the conductivity of the system and synergistically reduces the anode reaction overpotential with iridium and nickel, making 10mA / cm 2 The overpotential is less than 180mV, which is 15% lower than the overpotential of the existing catalyst anode. The platinum and anode catalyst loadings are 0.4-0.5mg / cm 2 and 1.25-1.35 mg / cm 2 The active area of ​​the cathode and anode is controlled at 3.6-4 cm 2 .

[0041] Example 3

[0042] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0043] like Figure 1 As shown, the preparation of the defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst and the catalytic oxygen evolution reaction at the anode of water electrolysis specifically include the following steps:

[0044] (1) First, a dicyandiamide aqueous solution (20 wt%) was freeze-dried for 24 h to obtain assembled dicyandiamide. Subsequently, the assembled dicyandiamide was treated in a 550°C vacuum tube furnace under a nitrogen atmosphere for 2 h. After cooling to room temperature, the resulting product was heated at 500°C in an air atmosphere for 1 h to obtain a carbon-nitrogen skeleton. This carbon-nitrogen skeleton is a graphene-like structure with a nitrogen-carbon ratio of 1.28 to 1.35 and a specific surface area of ​​25 to 30 m 2 / g, and the conductivity is 3.8~4.4×10 -5 The assembled dicyandiamide was treated at 550°C at a heating rate of 2-3°C / min.

[0045] (2) Take 0.165g of the carbon-nitrogen skeleton in step (1), 1.76g of lithium chloride powder and 10.5mL of isopropanol and add them to a ball mill for processing for 1.5h. Then place the mixed slurry in a 60℃ vacuum oven to dry, then place it in an alumina crucible and heat it in a 550℃ vacuum tube furnace for 2h. After that, disperse the treated powder into a 5wt% sulfuric acid solution. Rinse the mixture with deionized water several times until the pH of the rinse liquid is neutral, and then dry it in a 60℃ vacuum oven to obtain a defective carbon-nitrogen skeleton. This defective carbon-nitrogen skeleton is a graphene-like structure with a nitrogen-carbon ratio of 0.71-0.73 and a specific surface area of ​​440-459m 2 / g, electrical conductivity is 0.11-0.125S / cm, and the ball milling speed is 250-300rpm / min.

[0046] (3) 0.775 g of the defective framework material from step (2), 0.54 g of iridium chloride, 14.21 g of α-D-glucose, and 55 mL of deionized water were uniformly mixed and sonicated for 1 h. The mixture was then centrifuged four times with deionized water, and the resulting solid product was dried in an 80°C oven for 18 h.

[0047] (4) The solid product obtained in step (3) was transferred to a vacuum tube furnace filled with nitrogen atmosphere, and heated from room temperature to 800 ° C at a certain heating rate and maintained for 2 hours to obtain a defective carbon-nitrogen skeleton-supported single-atom iridium catalyst. This catalyst has a high thermal conductivity at 1.6 A / cm 2 Under the conditions of , the voltage is 1.79 ~ 1.82V, and the iridium mass activity of the catalyst is 740 ~ 745A / g Ir , ohmic impedance is 41.3~42.6mΩ / cm 2 The heating rate is 5-6°C / min.

[0048] (5) Take 1.25g of the sample obtained in step (4) and disperse it in 110mL of N,N-dimethylformamide and ultrasonicate for 1h. Then disperse 115mg of a mixture of nickel phthalocyanine and iron phthalocyanine into the ultrasonicated liquid and stir it at room temperature for 12h. Finally, the obtained liquid was centrifuged four times with deionized water to obtain a black solid, which was placed in an oven at 60℃ and dried for 12h to obtain a defective carbon nitrogen skeleton supported single atom iridium / iron-nickel catalyst. This catalyst has a high conductivity at 1.6A / cm 2 Under the conditions of 1.53~1.61V, the iridium mass activity of the catalyst is 901~915A / g Ir , ohmic impedance is 17.8~18.9mΩ / cm 2 The mass ratio of nickel phthalocyanine to iron phthalocyanine is 5:1 to 3:1.

[0049] (6) A membrane electrode was prepared using 60wt% platinum / carbon as the cathode catalyst, the sample obtained in step (5) as the anode catalyst, and Nafion 117 as the proton exchange membrane. A single proton exchange membrane electrolyzer was constructed from the inside out in the order of membrane electrode, porous current collector, and bipolar plate. During the anode oxygen evolution reaction, the defective carbon-nitrogen material, due to its special delocalized π bond structure, acts as an electron donor, providing more charges and nucleation sites for the catalytic reaction of iridium. The synergistic catalysis of iridium and nickel atoms reduces the energy barrier for the conversion of H2O to O2, especially the energy barrier for the elementary reaction from *OH to *O, and improves the reaction kinetic parameters. Iron improves the conductivity of the system and synergistically reduces the anode reaction overpotential with iridium and nickel, making 10mA / cm 2 The overpotential is lower than 185mV, which is 14% lower than the overpotential of the existing catalyst anode. The platinum and anode catalyst loadings are 0.4-0.5mg / cm 2 and 1.25-1.35 mg / cm 2 The active area of ​​the cathode and anode is controlled at 3.6-4 cm 2 .

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst, characterized in that: The following steps are included: The pretreated dicyandiamide is heated in a nitrogen atmosphere, cooled, and then heated again in an air atmosphere to obtain a carbon-nitrogen skeleton; The carbon-nitrogen skeleton, lithium chloride, and isopropanol were mixed and ball-milled, and the mixed slurry was dried and then heated to obtain a powder; wherein the mass volume ratio of the carbon-nitrogen skeleton, lithium chloride powder, and isopropanol was (0.135-0.165 g): (1.76-2.00 g): (9.5-10.5 mL); The powdered material is dispersed in a sulfuric acid solution and dried to obtain a defective carbon-nitrogen skeleton; The defective framework material, iridium chloride, α-D-glucose and water were uniformly mixed and ultrasonicated, and a solid product was obtained after centrifugation. After drying, the solid product was heated under a nitrogen atmosphere to obtain a defective carbon-nitrogen framework-supported single-atom iridium catalyst. The mass volume ratio of defective framework material, iridium chloride, α-D-glucose and water is (0.725-0.775 g): (0.54-0.58 g): (14.03-14.21 g): (55-65 mL); The defective carbon-nitrogen skeleton-supported single-atom iridium catalyst is dispersed in N,N-dimethylformamide and ultrasonicated, a mixture of nickel phthalocyanine and iron phthalocyanine is added, stirred and centrifuged, and the obtained solid is dried to obtain the defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst.

2. The method for preparing the defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst according to claim 1, characterized in that: When preparing the carbon-nitrogen skeleton, dicyandiamide was treated in a vacuum tube furnace at 550°C under a nitrogen atmosphere for 2 h, and the heating rate of dicyandiamide at 550°C was 2~3°C / min.

3. The method for preparing the defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst according to claim 1, characterized in that: When preparing defective carbon-nitrogen skeletons, the ball milling speed is 250~300 rpm / min.

4. The method for preparing the defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst according to claim 1, characterized in that: When preparing defective carbon-nitrogen skeleton-supported single-atom iridium catalysts, it is necessary to heat from room temperature to 800 °C and maintain it for 2 hours, with a heating rate of 5~6 °C / min.

5. The method for preparing the defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst according to claim 1, characterized in that: The mass ratio of nickel phthalocyanine to iron phthalocyanine is 5:1~3:

1.

6. A defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst prepared by the preparation method of the defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst according to any one of claims 1 to 5.

7. Use of the defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst according to claim 6, characterized in that: A membrane electrode was prepared using 60 wt% platinum / carbon as the cathode catalyst, a defective carbon-nitrogen skeleton-loaded single-atom iridium / iron-nickel catalyst as the anode catalyst, and Nafion 117 as the proton exchange membrane. A single proton exchange membrane electrolyzer was constructed from the inside out in the order of membrane electrode, porous current collector, and bipolar plate.

8. The use of the defective carbon-nitrogen skeleton-supported single-atom iridium / iron-nickel catalyst according to claim 7, characterized in that: The platinum and anode catalyst loadings were 0.4~0.5 mg / cm 2 and 1.25-1.35 mg / cm 2 The active area of ​​the anode and cathode is controlled at 3.6~4 cm 2 .

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