Carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, and preparation method and application thereof

Abstract

The present application relates to the technical field of hydrogen production catalyst for water electrolysis, in particular to a carbon-coated iridium dioxide hydrogen production catalyst for water electrolysis, a preparation method and application thereof, wherein the preparation method of the carbon-coated iridium dioxide hydrogen production catalyst for water electrolysis comprises the following steps: preparing a carbon-coated iridium dioxide precursor powder by using iridium compounds, carboxyl carbon compounds and an oxidizing agent, then performing a calcination oxidation reaction, immediately performing a rapid cooling treatment after the calcination is completed to obtain an initial catalyst, and finally obtaining the carbon-coated iridium dioxide hydrogen production catalyst for water electrolysis by washing, filtering and heating drying. The prepared catalyst has excellent electrocatalytic activity and stability, and the catalyst crystal has a microporous structure and a high specific surface area. The nano structure with a high specific surface area is beneficial to further improving the catalytic activity, and the catalyst load of Ir is reduced while ensuring the catalytic activity, thereby significantly reducing the cost. The catalyst has a good application prospect in the hydrogen evolution and oxygen evolution reactions of water electrolysis.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen production catalyst for water electrolysis, in particular to a carbon-coated iridium dioxide hydrogen production catalyst for water electrolysis, a preparation method and application thereof. BACKGROUND

[0002] Hydrogen, as a clean and efficient energy carrier and storage medium, has been widely concerned by research institutions and industries, and is widely considered to be a very promising alternative to fossil fuels in the future. At present, water electrolysis is an environmentally friendly and efficient method for hydrogen production. Proton exchange membrane (PEM) water electrolysis is a very promising technology that can efficiently produce high-purity hydrogen. IrO2, as a commercial electrocatalyst for anode oxygen evolution reaction (OER) in proton exchange membrane (PEM) water electrolysis cell, can maintain stability under strong acid and high corrosion conditions, and has excellent thermal stability, high electrical conductivity and many other advantages, making it an ideal electrocatalyst material.

[0003] However, the most comprehensive anode electrocatalyst developed is based on iridium dioxide material, but there are still many problems to be solved. For example, the catalytic activity of iridium dioxide is still to be further improved compared with ruthenium dioxide; the electrochemical stability of iridium dioxide is still poor at high potential; in addition, the reserves of iridium element in the earth's crust are extremely low, resulting in the price of iridium dioxide being still very expensive.

[0004] At present, iridium dioxide material has broad application prospects in many catalytic reactions, but its shortcomings such as poor catalytic activity, stability to be further improved, and high price greatly limit its application. SUMMARY

[0005] In order to overcome the shortcomings of the prior art, the first purpose of the present application is to provide a preparation method of a carbon-coated iridium dioxide hydrogen production catalyst for water electrolysis. The electrocatalytic activity and stability of the carbon-coated iridium dioxide hydrogen production catalyst for water electrolysis prepared by the preparation method are significantly improved, and the loading of iridium dioxide is reduced while ensuring the improvement of catalytic activity, thereby significantly reducing the cost.

[0006] In order to overcome the shortcomings of the prior art, the second purpose of the present application is to provide a carbon-coated iridium dioxide hydrogen production catalyst for water electrolysis. The carbon-coated iridium dioxide hydrogen production catalyst for water electrolysis has the advantages of high catalytic activity, good stability and low cost.

[0007] The third purpose of the present application is to provide an application of a carbon-coated iridium dioxide hydrogen production catalyst for water electrolysis in water electrolysis hydrogen evolution and oxygen evolution reactions.

[0008] To achieve the first purpose of the application, the technical solution adopted by the present application is as follows:

[0009] The application provides a preparation method of a carbon-coated iridium dioxide water electrolysis hydrogen production catalyst.

[0010] S1, preparing carbon-coated iridium dioxide precursor powder: after mixing iridium compounds, carboxyl carbon compounds and oxidants in a solvent, heating reaction is performed to prepare carbon-coated iridium dioxide precursor powder;

[0011] S2, preparing an initial catalyst: after calcination of the carbon-coated iridium dioxide precursor powder, cooling is performed in an ice water bath or liquid nitrogen to prepare an initial catalyst;

[0012] S3, preparing a finished catalyst: after washing, filtering and heating drying of the initial catalyst, the carbon-coated iridium dioxide water electrolysis hydrogen production catalyst is prepared.

[0013] The preparation method of the carbon-coated iridium dioxide water electrolysis hydrogen production catalyst provided by the application adopts iridium compounds, carboxyl carbon compounds and oxidants to prepare carbon-coated iridium dioxide precursor powder, then performs calcination and oxidation reaction, immediately performs rapid cooling treatment after the calcination is completed to prepare an initial catalyst, and after washing, filtering and heating drying, the carbon-coated iridium dioxide water electrolysis hydrogen production catalyst is prepared. In the process of the calcination and oxidation reaction, the metal precursor and the oxidant are fused in air at a high temperature, the carboxyl carbon compound is chelated with Ir as a chelating agent and a structure directing agent to assist the crystal orientation, the crystal face anisotropic growth of the prepared carbon-coated iridium dioxide water electrolysis hydrogen production catalyst has a lattice stretching strain effect, and the electrocatalytic activity and stability of the catalyst can be significantly improved. The crystal of the carbon-coated iridium dioxide water electrolysis hydrogen production catalyst has a microporous structure and a high specific surface area. The nanometer structure with a high specific surface area is beneficial to further improve the catalytic activity, and the catalyst can ensure the catalytic activity while reducing the loading amount of Ir, thereby significantly reducing the cost. In addition, nitrogen dioxide and oxygen are formed in the calcination and fusion process, and the nitrogen dioxide and oxygen are released from the reaction system as by-products. The only solid by-product is a compound formed after the oxidation of the oxidant, which can be easily dissolved in water for separation.

[0014] Further, in the step S1, the iridium compound is one or a combination of two or more of chloroiridic acid, potassium chloroiridate or iridium chloride; wherein the iridium compound is used as a precursor of the catalytically active substance iridium dioxide, and the chloroiridic acid, potassium chloroiridate or iridium chloride is used as a precursor of the catalytically active substance iridium dioxide, which is beneficial to the heating reaction in the solvent to prepare the carbon-coated iridium dioxide precursor powder. And / or

[0015] The carboxyl carbon compound is one or a combination of two or more of glycine hydrochloride, benzene tricarboxylic acid, benzoic acid or cysteine; wherein the carboxyl carbon compound acts as a chelating agent and a structure directing agent, on the one hand, it can be chelated with Ir to form a stable structure, on the other hand, it can assist the crystal orientation, so that the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst has crystal anisotropic growth and lattice stretching strain effect, and can significantly improve the electrocatalytic activity and stability, and the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst crystal has a microporous structure, a high specific surface area, and thus has the advantages of good electrocatalytic activity and stability. and / or

[0016] The oxidizing agent is one or a combination of two of sodium nitrate, potassium nitrate, sodium bromide or potassium bromide; wherein the selected sodium nitrate, potassium nitrate, sodium bromide or potassium bromide as an oxidizing agent, on the one hand, has the advantage of good oxidation performance, can promote the oxidation reaction of iridium compound to generate iridium dioxide in calcination, on the other hand, the solid by-product generated after the reaction of the selected oxidizing agent with the iridium compound is easy to dissolve in water and be separated out. and / or

[0017] The solvent is one or a combination of two of deionized water, isopropyl alcohol or ethanol. Wherein the deionized water, isopropyl alcohol or ethanol as a solvent, facilitates the dissolution of the iridium compound, the carboxyl carbon compound and the oxidizing agent, and facilitates the solvothermal reaction, and has the advantage of low material cost.

[0018] Further, the molar ratio of the iridium compound to the carboxyl carbon compound is 1:(1-10); and / or

[0019] The molar ratio of the iridium compound to the oxidizing agent is 1:(3-30); and / or

[0020] The mass-volume ratio of the iridium compound to the solvent is 800mg:(20-25)mL.

[0021] Further, in the step S1, the mixing is by ultrasonic and / or stirring for 0.5h-12h. In the solvothermal reaction, by using ultrasonic and / or stirring, the uniformity of carbon coating can be promoted.

[0022] Further, in the step S1, the heating reaction is carried out in an oven at 80℃-120℃ for 2h-12h.

[0023] Further, in the step S2, the calcination is to place the carbon-coated iridium dioxide precursor powder in a crucible, then put it into a muffle furnace and heat to 350℃-500℃, and keep it in air atmosphere for 1.5h-2.5h; wherein the carbon-coated iridium dioxide precursor powder is subjected to oxidation reaction and chelation effect in air atmosphere by calcination.

[0024] and / or

[0025] The heating rate of the heating in the muffle furnace is 1℃ / min-10℃ / min. The heating rate can facilitate the reaction and form the crystal with the microporous structure.

[0026] Further, in the step S2, the rapid cooling is performed in the ice water bath or liquid nitrogen for 1h-2h. After the calcination is completed, the calcination product is placed in the ice water bath or liquid nitrogen for cooling, so that the calcination product can be rapidly cooled, and a part of the carboxyl carbon can be retained and better complexed on the surface of the material to form the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst.

[0027] Further, in the step S3, the initial catalyst is washed with deionized water for 1-3 times and filtered; and / or

[0028] In the step S3, the heating and drying is that the initial catalyst after washing and filtering is placed in the oven at 60℃-80℃ for drying for 20h-30h.

[0029] To achieve the second object of the present application, the technical scheme adopted by the present application is as follows:

[0030] The present application provides a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by the preparation method of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst.

[0031] To achieve the third object of the present application, the technical scheme adopted by the present application is as follows:

[0032] The present application provides the application of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst. The carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by the preparation method of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst is applied in the electrolytic water hydrogen evolution and oxygen evolution reactions.

[0033] Compared with the prior art, the present application has the following beneficial effects:

[0034] (1) The preparation method of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst of the present application adopts iridium compounds, carboxyl carbon compounds and oxidizing agents to prepare carbon-coated iridium dioxide precursor powder, then performs calcination oxidation reaction, and immediately performs rapid cooling treatment after the calcination is completed to prepare an initial catalyst, which is washed, filtered and heated and dried to prepare the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst. In the calcination oxidation reaction process, the metal precursor and the oxidizing agent are fused in the air at a high temperature, the carboxyl carbon compound is chelated with Ir as a chelating agent and a structure directing agent to assist the crystal orientation, so that the crystal face anisotropic growth of the prepared carbon-coated iridium dioxide electrolytic water hydrogen production catalyst has a lattice stretching strain effect, and the electrocatalytic activity and stability can be significantly improved. The crystal of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst has a microporous structure and a high specific surface area. The nanostructure with a high specific surface area is beneficial to further improving the catalytic activity, and the load of Ir is reduced while the catalytic activity is ensured, thereby significantly reducing the cost.

[0035] (2) The preparation method of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst of the present application performs calcination on the carbon-coated iridium dioxide precursor powder. Nitrogen dioxide and oxygen are formed in the calcination fusion process, and the nitrogen dioxide and oxygen are released from the reaction system as by-products. The only solid by-product is the compound formed after the oxidation reaction, which can be easily dissolved in water for separation.

[0036] (3) The preparation method of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst of the present application performs cooling on the calcination product in an ice water bath or liquid nitrogen after the calcination of the carbon-coated iridium dioxide precursor powder is completed, so that the calcination product can be rapidly cooled, and a part of the carboxyl carbon can be retained and better complexed on the surface of the material to form the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst.

[0037] (4) The preparation method of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst of the present application has the characteristics of simple process, simple operation, low production cost and suitability for large-scale production.

[0038] (5) The carbon-coated iridium dioxide electrolytic water hydrogen production catalyst of the present application has a nanostructure with micropores, a particle size of about 10 nm, and a nanostructure with a high specific surface area, which is beneficial to further improving the catalytic activity, and the load of Ir is reduced while the catalytic activity is ensured, thereby having the advantage of low cost.

[0039] (6) The application of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, the application of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst in the hydrogen evolution and oxygen evolution reaction of water electrolysis, can significantly improve the electrocatalytic activity and stability, and since the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst is a nano structure with high specific surface area, it is beneficial to further improve the catalytic activity, and at the same time of ensuring the catalytic activity, the load of Ir is reduced, thereby significantly reducing the cost. Therefore, the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by the application has good application prospect in the hydrogen evolution and oxygen evolution reaction of water electrolysis. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0041] Figure 1 is a TEM and lattice fringe diagram of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by the present application embodiment 1. Figure 1 In the figure, a is a TEM diagram, and b is a lattice fringe diagram.

[0042] Figure 2 is a TEM and lattice fringe diagram of an iridium dioxide electrocatalyst prepared by the present application comparative example 1. Figure 2 In the figure, c is a TEM diagram, and d is a lattice fringe diagram.

[0043] Figure 3 is a SEM diagram of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by the present application embodiment 1.

[0044] Figure 4 is a SEM diagram of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by comparative example 2.

[0045] Figure 5 is an XED diagram of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by the present application embodiment 1 to embodiment 4.

[0046] Figure 6 is an XRD diagram of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by the present application embodiment 1, embodiment 5 to embodiment 7.

[0047] Figure 7 is an XRD diagram of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by the present application embodiment 8 to embodiment 12.

[0048] Figure 8is an electrochemical performance test diagram of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Embodiment 1 to Embodiment 4 of the present application.

[0049] Figure 9 is an electrochemical performance test diagram of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Embodiment 1, Embodiment 5 to Embodiment 7 of the present application.

[0050] Figure 10 is an electrochemical performance test diagram of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Embodiment 8 to Embodiment 12 of the present application.

[0051] Figure 11 is an electrochemical performance test diagram of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Embodiment 1, an iridium dioxide electrocatalyst prepared in Comparative Example 1 and commercial iridium dioxide.

[0052] Figure 12 is an electrochemical stability test result diagram of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Embodiment 1, an iridium dioxide electrocatalyst prepared in Comparative Example 1 and commercial iridium dioxide.

[0053] Figure 13 is an electrochemical performance comparison diagram of carbon-coated iridium dioxide electrolytic water hydrogen production catalysts prepared in Embodiment 1 and Comparative Example 2.

[0054] Figure 14 is an XPS spectrum diagram of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst of Embodiment 1 and an iridium dioxide electrocatalyst of Comparative Example 1.

[0055] Figure 15 is an EDS spectrum diagram of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Embodiment 1 of the present application.

[0056] Figure 16 is an EDS spectrum diagram of an iridium dioxide electrocatalyst prepared in Comparative Example 1. DETAILED DESCRIPTION

[0057] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clearly understood, the present application will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, and are not used to limit the present application.

[0058] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0059] The OER mentioned in the present application refers to an oxygen evolution reaction of an electrocatalyst.

[0060] In the embodiments of the present application, a preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst comprises the following steps:

[0061] S1, preparing a carbon-coated iridium dioxide precursor powder: after mixing an iridium compound, a carboxyl carbon compound and an oxidizing agent in a solvent, heating reaction is performed to prepare the carbon-coated iridium dioxide precursor powder;

[0062] S2, preparing an initial catalyst: after calcination of the carbon-coated iridium dioxide precursor powder, cooling is performed in an ice water bath or liquid nitrogen to prepare the initial catalyst;

[0063] S3, preparing a finished catalyst: washing, filtering and heating drying are performed on the initial catalyst to prepare the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst.

[0064] In some embodiments, in the step S1, the iridium compound is one or a combination of two or more of chloroiridic acid, potassium chloroiridate or iridium chloride; and / or

[0065] the carboxyl carbon compound is one or a combination of two or more of glycine hydrochloride, benzene tricarboxylic acid, benzoic acid or cysteine; and / or

[0066] the oxidizing agent is one or a combination of two or more of sodium nitrate, potassium nitrate, sodium bromide or potassium bromide; and / or

[0067] the solvent is one or a combination of two or more of deionized water, isopropyl alcohol or ethanol.

[0068] In some embodiments, the molar ratio of the iridium compound to the carboxyl carbon compound is 1:(1-10); and / or

[0069] the molar ratio of the iridium compound to the oxidizing agent is 1:(3-30); and / or

[0070] the mass-volume ratio of the iridium compound to the solvent is 800mg:(20-25)mL.

[0071] In some embodiments, in the step S1, the mixing is performed by ultrasonic and / or stirring for 0.5h-12h.

[0072] In some embodiments, in the step S1, the heating reaction is performed in an oven at 80℃-120℃ for 2h-12h.

[0073] In some embodiments, in the step S2, the calcination is placing the carbon-coated iridium dioxide precursor powder in a crucible, then placing it in a muffle furnace to heat to 350-500℃, and keeping it in an air atmosphere for 1.5-2.5h; and / or

[0074] The heating rate of the placing in the muffle furnace is 1-10℃ / min.

[0075] In some embodiments, in the step S2, the rapid cooling is performed in an ice water bath or liquid nitrogen for 1-2h.

[0076] In some embodiments, in the step S3, the initial catalyst is washed with deionized water 1-3 times and filtered; and / or

[0077] In the step S3, the heating and drying is placing the washed and filtered initial catalyst in an oven at 60-80℃ for 20-30h.

[0078] In the embodiments of the present application, a carbon-coated iridium dioxide catalyst for water electrolysis hydrogen production is prepared by the above-mentioned method for preparing a carbon-coated iridium dioxide catalyst for water electrolysis hydrogen production.

[0079] In the embodiments of the present application, the application of a carbon-coated iridium dioxide catalyst for water electrolysis hydrogen production is the application of the carbon-coated iridium dioxide catalyst for water electrolysis hydrogen production prepared by the above-mentioned method for preparing a carbon-coated iridium dioxide catalyst for water electrolysis hydrogen production in water electrolysis hydrogen evolution and oxygen evolution reactions.

[0080] The following will be described in conjunction with specific embodiments.

[0081] Embodiment 1

[0082] A method for preparing a carbon-coated iridium dioxide catalyst for water electrolysis hydrogen production comprises the following steps:

[0083] S1, preparing a carbon-coated iridium dioxide precursor powder: chloroiridic acid, glycine hydrochloride, and sodium nitrate are added to isopropyl alcohol, mixed by ultrasonic oscillation for 0.5h, then reacted in an oven at 120℃ for 12h to obtain a carbon-coated iridium dioxide precursor powder;

[0084] In this embodiment, the molar ratio of chloroiridic acid to glycine hydrochloride is 1:5; the molar ratio of chloroiridic acid to sodium nitrate is 1:5; and the mass-volume ratio of chloroiridic acid to isopropyl alcohol is 800mg:23mL.

[0085] S2, preparation of the initial catalyst: the carbon-coated iridium dioxide precursor powder was placed in a crucible, then placed in a muffle furnace to be calcined at 450℃ with a heating rate of 5℃ / min, and after holding in an air atmosphere for 2h, the crucible was placed in an ice water bath for rapid cooling for 1.5h to prepare the initial catalyst;

[0086] S3, preparation of the finished catalyst: the initial catalyst was washed once with deionized water and filtered, then placed in an oven at 60℃ for drying for 24h to prepare the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst.

[0087] Example 2

[0088] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, different from example 1 is that the molar ratio of chloroiridic acid to glycine hydrochloride is 1:1. The rest of the preparation method is the same as example 1.

[0089] Example 3

[0090] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, different from example 1 is that the molar ratio of chloroiridic acid to glycine hydrochloride is 1:3. The rest of the preparation method is the same as example 1.

[0091] Example 4

[0092] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, different from example 1 is that the molar ratio of chloroiridic acid to glycine hydrochloride is 1:10. The rest of the preparation method is the same as example 1.

[0093] Example 5

[0094] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, different from example 1 is that in step S2, the calcination temperature of the carbon-coated iridium dioxide precursor powder in the muffle furnace is 350℃. The rest of the preparation method is the same as example 1.

[0095] Example 6

[0096] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, different from example 1 is that in step S2, the calcination temperature of the carbon-coated iridium dioxide precursor powder in the muffle furnace is 400℃. The rest of the preparation method is the same as example 1.

[0097] Example 7

[0098] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, different from example 1 is that in step S2, the calcination temperature of the carbon-coated iridium dioxide precursor powder in the muffle furnace is 500 DEG C. The rest of the preparation method is the same as example 1.

[0099] Example 8

[0100] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, comprising the following steps:

[0101] S1, preparing carbon-coated iridium dioxide precursor powder: chloro iridic acid, benzenetricarboxylic acid and potassium nitrate are added to ethanol, mixed by ultrasonic oscillation for 1h, and then reacted in an oven at 100 DEG C for 10h to prepare carbon-coated iridium dioxide precursor powder;

[0102] In this embodiment, the molar ratio of chloro iridic acid to benzenetricarboxylic acid is 1:5; the molar ratio of chloro iridic acid to potassium nitrate is 1:6; and the mass-volume ratio of chloro iridic acid to ethanol is 800mg:22mL.

[0103] S2, preparing an initial catalyst: the carbon-coated iridium dioxide precursor powder is placed in a crucible, then heated to 450 DEG C at a heating rate of 5 DEG C / min in a muffle furnace for calcination, and after holding in air atmosphere for 2h, the crucible is placed in an ice water bath for rapid cooling for 1h to prepare an initial catalyst;

[0104] S3, preparing a finished catalyst: the initial catalyst is washed with deionized water for 2 times, filtered, and then placed in an oven at 70 DEG C for drying for 25h to prepare a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst.

[0105] Example 9

[0106] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, different from example 8 is that the molar ratio of chloro iridic acid to benzenetricarboxylic acid is 1:1. The rest of the preparation method is the same as example 8.

[0107] Example 10

[0108] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, different from example 8 is that the molar ratio of chloro iridic acid to benzenetricarboxylic acid is 1:3. The rest of the preparation method is the same as example 8.

[0109] Example 11

[0110] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, different from example 8 is that the molar ratio of chloro iridic acid to benzenetricarboxylic acid is 1:7. The rest of the preparation method is the same as example 8.

[0111] Example 12

[0112] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, different from example 8 is that the molar ratio of chloroiridic acid to benzene tricarboxylic acid is 1:9. The rest of the preparation method is the same as example 8.

[0113] Example 13

[0114] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, comprising the following steps:

[0115] S1, preparing a carbon-coated iridium dioxide precursor powder: potassium chloroiridate, benzoic acid and sodium bromide are added to deionized water, mixed by stirring for 12h, and then reacted in an oven at 80℃ for 8h to obtain the carbon-coated iridium dioxide precursor powder;

[0116] In this embodiment, the molar ratio of potassium chloroiridate to benzoic acid is 1:1; the molar ratio of potassium chloroiridate to sodium bromide is 1:3; and the mass-volume ratio of potassium chloroiridate to deionized water is 800mg:20mL.

[0117] S2, preparing an initial catalyst: the carbon-coated iridium dioxide precursor powder is placed in a crucible, then heated to 400℃ at a heating rate of 1℃ / min in a muffle furnace, and then incubated in an air atmosphere for 2.5h, and then the crucible is placed in liquid nitrogen for rapid cooling for 1h to obtain the initial catalyst;

[0118] S3, preparing a finished catalyst: the initial catalyst is washed with deionized water for 3 times, filtered, and then dried in an oven at 80℃ for 20h to obtain the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst.

[0119] Example 14

[0120] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, comprising the following steps:

[0121] S1, preparing a carbon-coated iridium dioxide precursor powder: iridium chloride, cysteine and potassium bromide are added to isopropyl alcohol, mixed by stirring for 0.5h, and then reacted in an oven at 90℃ for 11h to obtain the carbon-coated iridium dioxide precursor powder;

[0122] In this embodiment, the molar ratio of iridium chloride to cysteine is 1:4; the molar ratio of iridium chloride to potassium bromide is 1:30; and the mass-volume ratio of iridium chloride to isopropyl alcohol is 800mg:25mL.

[0123] S2, preparing an initial catalyst: placing the carbon-coated iridium dioxide precursor powder in a crucible, then placing it in a muffle furnace to be calcined at 500℃ at a heating rate of 10℃ / min, and after keeping it in an air atmosphere for 1.5h, placing the crucible in an ice water bath to be rapidly cooled for 2h, thereby preparing the initial catalyst;

[0124] S3, preparing a finished catalyst: washing the initial catalyst with deionized water twice, filtering, and then placing it in an oven at 65℃ to be dried for 30h, thereby preparing the carbon-coated iridium dioxide catalyst for hydrogen production by water electrolysis.

[0125] Example 15

[0126] A method for preparing a carbon-coated iridium dioxide catalyst for hydrogen production by water electrolysis, comprising the following steps:

[0127] S1, preparing carbon-coated iridium dioxide precursor powder: adding chloroiridic acid, glycine hydrochloride, sodium nitrate, and potassium nitrate to ethanol, mixing using ultrasonic waves for 12h, and then reacting in an oven at 110℃ for 2h, thereby preparing the carbon-coated iridium dioxide precursor powder;

[0128] In this example, the molar ratio of chloroiridic acid to glycine hydrochloride was 1:7; the molar ratio of chloroiridic acid to oxidizing agent was 1:20; and the mass-volume ratio of chloroiridic acid to ethanol was 800mg:24mL.

[0129] S2, preparing an initial catalyst: placing the carbon-coated iridium dioxide precursor powder in a crucible, then placing it in a muffle furnace to be calcined at 400℃ at a heating rate of 4℃ / min, and after keeping it in an air atmosphere for 1.8h, placing the crucible in liquid nitrogen to be rapidly cooled for 1.3h, thereby preparing the initial catalyst;

[0130] S3, preparing a finished catalyst: washing the initial catalyst with deionized water once, filtering, and then placing it in an oven at 75℃ to be dried for 22h, thereby preparing the carbon-coated iridium dioxide catalyst for hydrogen production by water electrolysis.

[0131] Example 16

[0132] A method for preparing a carbon-coated iridium dioxide catalyst for hydrogen production by water electrolysis, comprising the following steps:

[0133] S1, preparing carbon-coated iridium dioxide precursor powder: adding chloroiridic acid, potassium chloroiridate, glycine hydrochloride, benzene tricarboxylic acid, and sodium nitrate to isopropyl alcohol, mixing using stirring for 5h, and then reacting in an oven at 95℃ for 6h, thereby preparing the carbon-coated iridium dioxide precursor powder;

[0134] In this embodiment, the molar ratio of iridium compound to glycine hydrochloride is 1:10; the molar ratio of iridium compound to sodium nitrate is 1:10; the mass-volume ratio of iridium compound to isopropyl alcohol is 800 mg:23 mL.

[0135] S2, preparing an initial catalyst: placing the carbon-coated iridium dioxide precursor powder in a crucible, then placing it in a muffle furnace to calcine at a heating rate of 8 ℃ / min to 470 ℃, and after holding in an air atmosphere for 2.1 h, placing the crucible in an ice water bath for rapid cooling for 1.8 h to prepare the initial catalyst;

[0136] S3, preparing a finished catalyst: washing the initial catalyst with deionized water 2 times and filtering, then placing it in an oven at 73 ℃ for drying for 26 h to prepare the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst.

[0137] Example 17

[0138] A carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by any one of the preparation methods of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst in the above examples 1 to 15, and the application of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst in the electrolytic water hydrogen evolution and oxygen evolution reactions.

[0139] Comparative Example 1

[0140] A preparation method of an iridium dioxide electrocatalyst, the difference between the present comparative example and example 1 is that in step S1, glycine hydrochloride is not added. The rest of the preparation method is the same as that of example 1.

[0141] Comparative Example 2

[0142] A preparation method of a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, the difference between the present embodiment and example 1 is that in step S2 of preparing an initial catalyst: placing the carbon-coated iridium dioxide precursor powder in a crucible, then placing it in a muffle furnace to calcine, after the muffle furnace stops heating, naturally cooling to room temperature before taking out the crucible to prepare the initial catalyst. The rest of the preparation method is the same as that of example 1.

[0143] (I) Transmission electron microscopy morphology characterization

[0144] A carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by example 1 and an iridium dioxide electrocatalyst prepared by comparative example 1 were respectively characterized by transmission electron microscopy (TEM). The TEM and lattice fringe images of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by example 1 are shown in Figure 1 The TEM and lattice fringe images of the iridium dioxide electrocatalyst prepared by comparative example 1 are shown in Figure 2 ​

[0145] Figure 1 In the figure, a is a TEM image, and b is a lattice fringe image. Figure 2 In the figure, c is a TEM image, and d is a lattice fringe image.

[0146] From Figure 1 and Figure 2 It can be seen by analyzing and comparing the TEM images of Figure 1 and Figure 2 The carbon-coated iridium dioxide electrolytic hydrogen production catalyst prepared in Example 1 has a uniform carbon protective layer wrapped on the surface of the particles, and the particle size is obviously smaller before and after comparison, please refer to a in Figure 1 and c in Figure 2 By analyzing and comparing the lattice fringe images of Figure 1 and Figure 2 It is also observed that the carbon-coated iridium dioxide electrolytic hydrogen production catalyst prepared in Example 1 has selective growth of crystal faces (101 in the figure) and lattice stretching strain, please refer to b in Figure 2 and d in Figure 2 .

[0147] (II) Morphology characterization by scanning electron microscope

[0148] The carbon-coated iridium dioxide electrolytic hydrogen production catalyst prepared in Example 1 and Comparative Example 2 was subjected to morphology characterization by scanning electron microscope (SEM). The SEM image of the carbon-coated iridium dioxide electrolytic hydrogen production catalyst prepared in Example 1 is shown in Figure 3 The SEM image of the carbon-coated iridium dioxide electrolytic hydrogen production catalyst prepared in Comparative Example 2 is shown in Figure 4 .

[0149] From Figure 3 It can be seen that the particles of the carbon-coated iridium dioxide electrolytic hydrogen production catalyst prepared in Example 1 are spherical and uniformly dispersed, and will not cluster into blocks, thereby making the prepared carbon-coated iridium dioxide electrolytic hydrogen production catalyst have a high specific surface area, which is beneficial to further improving the catalytic activity.

[0150] From Figure 4 It can be seen that because the carbon-coated iridium dioxide electrolytic hydrogen production catalyst prepared in Comparative Example 2 is not rapidly cooled after calcination and holding, most of the particles are agglomerated into blocks, thereby having a low specific surface area, resulting in poor electrocatalytic activity.

[0151] Therefore, the present application can make the particles of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst spherical, uniformly distributed, not clustered into blocks, and have a high specific surface area, thereby improving the electrocatalytic activity, by calcining and heat preserving the carbon-coated iridium dioxide precursor powder, then placing it in an ice water bath or liquid nitrogen for rapid cooling in the initial catalyst preparation step S2.

[0152] (III) X-ray diffraction analysis

[0153] The carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Example 1 to Example 4 was subjected to X-ray diffraction analysis (XRD), as shown in Figure 5 . Figure 5 In the figure, the curve marked "1:5" refers to Example 1, the curve marked "1:1" refers to Example 2, the curve marked "1:3" refers to Example 3, and the curve marked "1:10" refers to Example 4.

[0154] As can be seen from Figure 5 , the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by adding glycine hydrochloride with different molar content can prove that the glycine hydrochloride is successfully wrapped on the surface of the particles in the form of carbon coating, causing low-angle lattice shift.

[0155] The carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Example 1, Example 5 to Example 7 was subjected to X-ray diffraction analysis (XRD), as shown in Figure 6 . Figure 6 In the figure, the curve marked "450℃" refers to Example 1, the curve marked "350℃" refers to Example 5, the curve marked "400℃" refers to Example 6, and the curve marked "500℃" refers to Example 7.

[0156] As can be seen from Figure 6 , the crystallinity of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in the initial catalyst preparation step S2 is different under different calcination temperature conditions. It is shown that by adjusting the calcination temperature, the crystallinity of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst can also change significantly.

[0157] The carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Example 8 to Example 12 was subjected to X-ray diffraction analysis (XRD), as shown in Figure 7 . Figure 7 In the figure, the curve marked "1:5" refers to Example 8, the curve marked "1:1" refers to Example 9, the curve marked "1:3" refers to Example 10, the curve marked "1:7" refers to Example 11, and the curve marked "1:9" refers to Example 12.

[0158] Depend on Figure 7 It can be seen from the XRD pattern analysis that the carbon-coated iridium dioxide electrolysis hydrogen production catalysts prepared by adding different molar amounts of benzoic acid showed a peak of carboxyl carbon at a diffraction angle of about 13 degrees. As the amount of benzoic acid added increased, the peak intensity first became stronger and then weaker, reaching its peak value when the molar ratio of chloroiridium acid to benzoic acid was 1:5. Moreover, the carbon-coated iridium dioxide electrolysis hydrogen production catalyst of Example 8 showed the best OER activity, indicating that carboxyl carbon does indeed play an optimizing role in OER activity.

[0159] (iv) Electrochemical performance testing

[0160] The methods used for electrochemical performance testing are as follows:

[0161] (1) Preparation of working electrode: The catalyst slurry was prepared by mixing the catalyst powder (4 mg) with ultrapure water (500 μL), ethanol (500 μL) and Nafion solution (40 μL), and then drop-coated on glassy carbon electrode (or carbon paper) to achieve a catalyst loading of 125 μg / L.

[0162] (2) Electrolyte preparation: Add 7 mL of high-concentration perchloric acid to 1000 mL of ultrapure water and stir until room temperature to obtain 0.1 M HClO4 electrolyte.

[0163] (3) Electrochemical Testing: Electrochemical performance and stability were tested in a three-electrode battery system. In the three-electrode system, a graphite rod was used as the counter electrode, Ag / AgCl as the reference electrode, and the prepared catalyst as the working electrode in an electrolyte of 0.1 M HClO4. The system was connected to an electrochemical workstation to test its linear voltammetry (LSV) curve to evaluate its electrochemical oxygen evolution performance. Electrochemical tests were performed in an oxygen-saturated electrolyte of 0.1 M HClO4 at 25 °C. To ensure data reliability, the OER activity test was repeated three times, and the average of the three measurements was taken as the measured value. The potential was calibrated using a reversible hydrogen electrode for each measurement. The linear sweep voltammetry was performed from 1.2 V to 1.8 V at a scan rate of 5 mVs. -1 Stability assessment was conducted at 10 mA / cm². -1 Perform a time-potential method test.

[0164] According to the above electrochemical performance testing method, the carbon-coated iridium dioxide electrolytic hydrogen production catalysts prepared in Examples 1 to 4 were subjected to electrochemical performance tests respectively. If the test results are as follows... Figure 8 As shown. By Figure 8 It is known that among the carbon-coated iridium dioxide electrolysis hydrogen production catalysts prepared by adjusting the addition of glycine hydrochloride in different molar ratios, the molar ratio of iridium compound to carboxylated carbon compound is 1:5, which exhibits the best OER activity.

[0165] The carbon-coated iridium dioxide electrolytic hydrogen production catalysts prepared in Examples 1, 5 to 7 were subjected to electrochemical performance tests. If the test results are... Figure 9 As shown. By Figure 9 It can be seen that the OER activities of the carbon-coated iridium dioxide electrolysis water-to-hydrogen catalyst prepared under different calcination temperatures during the initial catalyst preparation in step S2 are different. Among them, the carbon-coated iridium dioxide electrolysis water-to-hydrogen catalyst prepared at a calcination temperature of 450℃ exhibits the best OER activity. Therefore, in Example 1, when the molar ratio of chloroiridium acid to glycine hydrochloride is 1:5 and the calcination temperature is 450℃, the carbon-coated iridium dioxide electrolysis water-to-hydrogen catalyst prepared has the lowest overpotential.

[0166] The carbon-coated iridium dioxide electrolytic hydrogen production catalysts prepared in Examples 8 to 12 were subjected to electrochemical performance tests. If the test results are... Figure 10 As shown. By Figure 10 It can be seen that, in Example 8, when the molar ratio of chloroiridium acid to triphenylcarboxylic acid is 1:5 and the calcination temperature is 450°C, the carbon-coated iridium dioxide electrolysis catalyst for hydrogen production has the smallest overpotential.

[0167] Therefore, the above tests show that when the molar ratio of iridium compound to carboxylated carbon compound is 1:5 and the calcination temperature is 450℃, the carbon-coated iridium dioxide electrolysis catalyst for hydrogen production has the smallest overpotential.

[0168] (V) Electrochemical performance and electrochemical impedance spectroscopy of Example 1, Comparative Example 1 and commercial iridium dioxide

[0169] The carbon-coated iridium dioxide electrolytic hydrogen production catalyst prepared in Example 1, the iridium dioxide electrocatalyst prepared in Comparative Example 1, and commercially available iridium dioxide were subjected to electrochemical performance tests. The electrochemical performance test results are as follows: Figure 11 As shown.

[0170] Depend on Figure 11 It is evident that carboxyl carbon compounds (such as glycine hydrochloride) significantly enhance electrochemical performance. The carbon-coated iridium dioxide electrolysis catalyst for hydrogen production prepared by coating iridium dioxide with carboxyl carbon compounds exhibits a significant advantage in electrochemical performance compared to Comparative Example 1 and the commercial iridium dioxide catalyst.

[0171] (vi) Electrochemical stability test

[0172] The carbon-coated iridium dioxide electrolytic hydrogen production catalyst prepared in Example 1, the iridium dioxide electrocatalyst prepared in Comparative Example 1, and commercially available iridium dioxide were subjected to electrochemical stability tests.

[0173] Using the above-described electrochemical performance testing method, the carbon-coated iridium dioxide electrolytic hydrogen production catalyst prepared in Example 1, the iridium dioxide electrocatalyst prepared in Comparative Example 1, and commercially available iridium dioxide were subjected to electrochemical testing for more than 90 hours. The test results are as follows: Figure 12 As shown.

[0174] Depend on Figure 12 It can be seen that the electrochemical stability of the iridium dioxide electrocatalyst prepared in Comparative Example 1 and commercially available iridium dioxide is relatively poor. However, the stability test of the carbon-coated iridium dioxide electrolysis hydrogen production catalyst prepared in this invention reaches more than 90 hours, which shows excellent durability compared with Comparative Example 1 and commercial iridium dioxide.

[0175] (vii) Comparison of electrochemical performance between Example 1 and Comparative Example 2

[0176] The carbon-coated iridium dioxide electrolysis catalysts for hydrogen production from water prepared in Example 1 and Comparative Example 2 were subjected to electrochemical performance tests, and the test results are as follows: Figure 13 As shown.

[0177] Depend on Figure 13 As can be seen, in Example 1, by calcining and holding the carbon-coated iridium dioxide precursor powder at a constant temperature in step S2 of the initial catalyst preparation, followed by rapid cooling in an ice-water bath or liquid nitrogen, the electrochemical performance of the carbon-coated iridium dioxide water electrolysis hydrogen production catalyst can be improved, resulting in better OER activity. In contrast, Comparative Example 2, due to the lack of rapid cooling after calcination and holding, resulted in a lower electrochemical performance of the prepared carbon-coated iridium dioxide water electrolysis hydrogen production catalyst compared to Example 1, thus leading to lower OER activity.

[0178] (viii) X-ray photoelectron spectroscopy analysis

[0179] The carbon-coated iridium dioxide electrolytic hydrogen production catalyst prepared in Example 1 and the iridium dioxide electrocatalyst prepared in Comparative Example 1 were subjected to X-ray photoelectron spectroscopy (XPS C 1s) analysis, respectively. The analysis results are as follows: Figure 14 As shown.

[0180] Depend on Figure 14 As can be seen, the XPS C 1s spectrum of the carbon-coated iridium dioxide electrolysis hydrogen production catalyst prepared in Example 1 showed an OC=O signal, indicating that some carboxyl carbon was retained on the material surface under rapid cooling.

[0181] (ix) EDS energy dispersive spectroscopy analysis

[0182] The carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Example 1 and the iridium dioxide electrocatalyst prepared in Comparative Example 1 were subjected to EDS spectrum analysis, and EDS images of elements C (red), Ir (blue) and O (green) were obtained, and the test results are shown in Figure 15 and 16 . Among them, the EDS spectrum analysis of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Example 1 is shown in Figure 15 , and the EDS spectrum analysis of the iridium dioxide electrocatalyst prepared in Comparative Example 1 is shown in Figure 16 .

[0183] According to the EDS spectrum analysis of Figure 15 and Figure 16 , the element content distribution of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Example 1 and the iridium dioxide electrocatalyst prepared in Comparative Example 1 is shown in Table 1. In addition, the element content distribution analysis of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Example 1 was also carried out after 90 hours of electrochemical stability test, as shown in Table 1.

[0184] Table 1 Element content distribution of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst of Example 1 and the iridium dioxide electrocatalyst of Comparative Example 1

[0185]

[0186] As can be seen from Table 1, the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared in Example 1 has a high carbon content of nearly 50% due to the presence of carboxyl carbon attached to the surface of the material. After 90 hours of electrochemical stability test of the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst of Example 1, the carbon content was still found to be stable at a certain level, indicating that the carboxyl carbon can indeed exist stably during the OER process and can prevent excessive dissolution of Ir.

[0187] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a carbon-coated iridium dioxide electrolytic water hydrogen production catalyst, characterized by, The method comprises the following steps: S1, preparing carbon-coated iridium dioxide precursor powder: after mixing iridium compound, carboxyl carbon compound and oxidizing agent in solvent, heating reaction is carried out to prepare carbon-coated iridium dioxide precursor powder; S2, preparing initial catalyst: after calcination of the carbon-coated iridium dioxide precursor powder, cooling in ice water bath or liquid nitrogen is carried out to prepare initial catalyst; S3, preparing finished catalyst: washing, filtering and heating drying of the initial catalyst are carried out to prepare the carbon-coated iridium dioxide electrolytic water hydrogen production catalyst. The oxidizing agent is one or a combination of two of sodium nitrate, potassium nitrate, sodium bromide or potassium bromide.

2. The preparation method of the carbon-coated iridium dioxide catalyst for hydrogen production by water electrolysis according to claim 1, characterized in that, In the step S1, the iridium compound is one or a combination of two or more of chloroiridic acid, potassium chloroiridate or iridium chloride; and / or The carboxyl carbon compound is one or a combination of two or more of glycine hydrochloride, benzene tricarboxylic acid, benzoic acid or cysteine; and / or The solvent is one or a combination of two of deionized water, isopropyl alcohol or ethanol.

3. The preparation method of the carbon-coated iridium dioxide catalyst for hydrogen production by water electrolysis according to claim 1, characterized in that, The molar ratio of the iridium compound to the carboxyl carbon compound is 1:(1-10); and / or The molar ratio of the iridium compound to the oxidizing agent is 1:(3-30); and / or The mass-volume ratio of the iridium compound to the solvent is 800mg:(20-25)mL.

4. The preparation method of a carbon-coated iridium dioxide electrolysis hydrogen production catalyst as described in claim 1, characterized in that, In the step S1, the mixing is carried out by ultrasonic and / or stirring for 0.5h-12h.

5. The method of claim 1, wherein the carbon-coated iridium dioxide hydrogen production catalyst is prepared by the steps of: preparing a solution of iridium chloride; adding a reducing agent to the solution of iridium chloride; and adding a carbon source to the solution of iridium chloride. In the step S1, the heating reaction is carried out in an oven at 80℃-120℃ for 2h-12h.

6. The preparation method of a carbon-coated iridium dioxide electrolysis hydrogen production catalyst as described in claim 1, characterized in that, In the step S2, the calcination is that the carbon-coated iridium dioxide precursor powder is placed in a crucible, then heated to 350℃-500℃ in a muffle furnace and kept in air atmosphere for 1.5h-2.5h; and / or The heating rate in the muffle furnace is 1℃ / min-10℃ / min.

7. The preparation method of the carbon-coated iridium dioxide catalyst for hydrogen production by water electrolysis according to claim 1, characterized in that, In the step S2, the cooling in ice water bath or liquid nitrogen is carried out for 1h-2h.

8. The preparation method of a carbon-coated iridium dioxide electrolysis hydrogen production catalyst as described in claim 1, characterized in that, In the step S3, the initial catalyst is washed with deionized water for 1-3 times and filtered; and / or In the step S3, the heating drying is that the washed and filtered initial catalyst is placed in an oven at 60℃-80℃ for 20h-30h.

9. A carbon-coated iridium dioxide catalyst for hydrogen production by water electrolysis, characterized by, The carbon-coated iridium dioxide electrolytic water hydrogen production catalyst is prepared by the method of any one of claims 1 to 8.

10. Use of a carbon-coated iridium dioxide catalyst for electrolysis of water to produce hydrogen, characterized in that, The carbon-coated iridium dioxide electrolytic water hydrogen production catalyst prepared by the method of any one of claims 1 to 8 is applied in electrolytic water hydrogen evolution and oxygen evolution reaction.

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