Hydrogen production catalyst as well as preparation method and application thereof

Abstract

The invention relates to the technical field of materials, and particularly discloses a hydrogen production catalyst and a preparation method and application thereof. The method for preparing the catalyst comprises the following steps: (1) dissolving metal salt in ethanol to obtain a metal salt solution, and fully mixing the metal salt solution with water and 1, 2-epoxybutane to obtain a precursor solution; the volume ratio of the water to the 1, 2-epoxybutane is 1: (1-5); (2) fully infiltrating a foamed nickel matrix in the precursor solution; (3) carrying out drying and curing treatment on the infiltrated foamed nickel substrate by adopting Joule heating equipment; the treatment time is 1-10 seconds; and (4) heat treatment is conducted in the atmosphere, the heat treatment temperature ranges from 200 DEG C to 500 DEG C, and the time ranges from 0.5 h to 3 h. The catalyst is high in loading capacity, low in overpotential, stable in performance, suitable for the field of hydrogen production through water electrolysis, simple, convenient and efficient in preparation process, low in cost and good in industrial application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of materials, and in particular, to a hydrogen production catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] Hydrogen production by electrolyzing water has become a research hotspot in the field of clean energy as a green and sustainable hydrogen production technology. Its core lies in developing efficient electrolyzed water catalysts to improve the performance of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). However, existing catalysts still face challenges in terms of activity, stability, cost, and feasibility of large-scale application. Improving the activity and stability of the catalyst while reducing the preparation cost is the key to solving the bottleneck of hydrogen production by electrolyzing water.

[0003] Currently, transition metal-based catalysts have received extensive attention due to their excellent activity and stability in alkaline electrolyzed water. Among them, foam metals (such as nickel foam) have become ideal catalyst substrates due to their three-dimensional porous structure, high specific surface area, and good electrical conductivity. However, existing foam metal-based catalysts have significant problems in practical applications: one is the low loading of active components, usually less than 1Mg / cm 2 , which is difficult to meet the requirements of high current density in industrialization; the second is the weak binding force between the catalyst and the substrate, which is easy to fall off, resulting in poor stability and short lifespan; the third is that traditional preparation methods (such as solution deposition, oven drying, or high-temperature roasting) take a long time (from several hours to several days), consume high energy, and have low efficiency, restricting rapid large-scale production.

[0004] For example, CN111101151A reports a molybdenum-doped cobalt selenide nickel foam composite electrode, which exhibits efficient bifunctional catalytic activity and is suitable for industrial water electrolysis, but the problem of poor binding between the catalyst and the substrate remains unsolved. CN118086955A proposes a method for preparing a structured electrolyzed water catalyst by sulfur / phosphorus / nitrogen reduction roasting, which improves the surface activity and stability, but the process is complex and the equipment requirements are high, increasing the production difficulty. CN114016050A discloses an iron-molybdenum-doped nickel sulfide / nickel foam bifunctional electrode, which shows certain performance advantages, but the long-term stability of the substrate is insufficient, and the preparation process takes a long time.

[0005] In summary, the existing technology has obvious deficiencies in achieving high loading, strong binding force, and rapid preparation, and the process complexity and high cost further limit its industrial application. Therefore, developing a simple and efficient preparation method for electrolyzed water catalysts that takes into account high loading and rapid preparation has become an urgent technical problem to be solved. Summary of the Invention

[0006] One of the objectives of the present invention is to provide a hydrogen production catalyst with high loading, long lifespan, good stability, and short preparation cycle.

[0007] The present invention provides a method for preparing a catalyst, which includes: (1) Dissolving a metal salt in ethanol to obtain a metal salt solution, and then fully mixing it with water and 1,2-epoxybutane to obtain a precursor solution; The concentration of the metal salt in the metal salt solution is 0.01 - 2.0 M; The volume ratio of the total volume of the metal salt solution to water and 1,2-epoxybutane is 5:(1 - 3); The volume ratio of water to 1,2-epoxybutane is 1:(1 - 5); (2) Fully immersing a clean nickel foam substrate in the precursor solution prepared in step (1); (3) Using a Joule heating device to perform drying and curing treatments on the immersed nickel foam substrate obtained in step (2); the time for the drying and curing treatments is 1 - 10 seconds; (4) Performing heat treatment in an atmosphere, the temperature of the heat treatment is 200 - 500 °C (preferably, 200 - 450 °C), the time for the heat treatment is 0.5 - 3 hours (preferably, 1 - 3 hours), and the gas in the atmosphere includes one or more of argon, nitrogen, hydrogen, and ammonia.

[0008] The present invention first uses the room-temperature sol-gel method to prepare a gel-like precursor solution with a specific composition, adjusts the hydrolysis rate by controlling the ratio of water and 1,2-epoxybutane, ensures the uniform distribution and high loading amount of metal elements in the gel, and prepares a specific gel-like metal hydroxide. Then, by utilizing the confinement adsorption effect of the gel-like precursor solution in the pore structure of the nickel foam (realized by the viscosity of the gel-like precursor solution and the three-dimensional pore structure of the nickel foam), the active components are uniformly distributed and firmly attached on the surface and inside the pores of the nickel foam substrate, avoiding shedding during subsequent treatments. Then, first use a Joule heating device to perform rapid drying and curing treatments on the immersed nickel foam substrate, and then perform heat treatment in different atmospheres according to the usage requirements. The finally obtained catalyst has a high loading amount, good stability, and can significantly shorten the treatment time compared with traditional room-temperature drying or oven drying.

[0009] In the method of the present invention, the heat treatment can be carried out in different atmospheres to regulate the composition and performance of the catalyst according to the application scenario of the catalyst (such as the bifunctional catalytic activity of the catalyst in the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER)).

[0010] In the method of the present invention, the metal salt is selected from one or more of nickel nitrate, cobalt nitrate, iron nitrate, copper nitrate, chromium nitrate, manganese nitrate, molybdenum chloride, tungsten chloride, ruthenium chloride, and iridium chloride.

[0011] Specifically, according to the solubility of the metal salt and the requirements of the electrode performance, the concentration of the metal salt in the metal salt solution can be flexibly adjusted (preferably 0.15 - 2 M). The gel-like precursor solution (gel-like metal hydroxide) contains one or more metal elements selected from nickel, cobalt, iron, copper, chromium, manganese, molybdenum, tungsten, ruthenium, and iridium. When multiple metal elements are used in combination, the performance of the catalyst can be improved through synergistic effects.

[0012] In the catalyst of the present invention, 0.5 - 200 mg of the active metal component can be loaded on the surface of each square centimeter of the nickel foam substrate, and the loading amount of the active metal component can be adjusted by the concentration of the metal salt.

[0013] In step (3) of the method of the present invention, during the drying and curing treatment, the voltage of the Joule heating device is 8 - 15 V, and the current is 3 - 8 A.

[0014] The Joule heating device is powered by a DC power supply, and uses the current between the electrodes to generate a thermal effect to achieve rapid drying and curing of the infiltrated substrate, shortening the treatment time by more than 95% compared with the traditional oven heating method.

[0015] In step (1) of the method of the present invention, the time for sufficient mixing is 30 - 60 minutes.

[0016] In step (2) of the method of the present invention, the time for sufficient infiltration is 10 - 20 minutes.

[0017] In step (4) of the method of the present invention, the heating rate during the heat treatment is 1 - 5 °C / minute.

[0018] In the method of the present invention, the cleaning method of the nickel foam substrate includes: sequentially ultrasonic cleaning with hydrochloric acid, water, and ethanol for 10 - 15 minutes, and then performing vacuum drying.

[0019] Before infiltration, the nickel foam substrate can remove the surface oxide layer and impurities through ultrasonic cleaning. The cleaning solution is preferably 3M HCl solution, deionized water, and ethanol in sequence, and then it can be dried under vacuum conditions of 50 °C and -0.1 MPa.

[0020] The present invention also provides a catalyst prepared by the above method.

[0021] The catalyst of the present invention has an active layer with a high loading amount of the active metal component, and the loading amount is 0.5 - 200 mg / cm 2 , and shows a low overpotential and excellent long-term stability in the electrolysis of water reaction, wherein the metal is selected from one or more of nickel, cobalt, iron, copper, chromium, manganese, molybdenum, tungsten, ruthenium, and iridium.

[0022] The catalyst of the present invention in 1M KOH electrolyte, the current density is 100 mA / cm 2When the overpotential of the oxygen evolution reaction (OER) is lower than 320 mV and the overpotential of the hydrogen evolution reaction (HER) is lower than 160 mV.

[0023] The present invention also provides an application of the above catalyst in hydrogen production by electrolyzing water.

[0024] The catalyst of the present invention is a structured electrolyzed water catalyst. By optimizing the surface structure design, the electrocatalytic performance of the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) in electrolyzed water can be significantly improved, and it is particularly suitable for the industrial application of alkaline electrolyzed water for hydrogen production.

[0025] The present invention also provides a method for hydrogen production, which includes the step of electrolyzing water with the above catalyst.

[0026] The beneficial effects of the present invention are at least as follows: High loading and strong binding force: Through the confined adsorption of a specific gel-like precursor solution, the present invention realizes a high loading amount (0.5 - 200 Mg / cm 2 ) of the active component on the nickel foam substrate, and binds firmly to the substrate, effectively reducing shedding during use, and improving the stability and lifespan of the catalyst.

[0027] Rapid preparation and low energy consumption: Through Joule heating technology, the present invention shortens the drying and curing time to 1 - 10 seconds, saving more than 95% of the time compared with traditional oven heating, with low energy consumption, and significantly improving production efficiency.

[0028] Simple process and low cost: The present invention does not require high-temperature and high-pressure equipment, has a simple process, uses ethanol as a solvent, the metal salt raw materials are widely available, the preparation process is safe and simple, and the equipment and production costs are reduced.

[0029] Excellent catalytic performance: The catalyst prepared by the present invention has a low overpotential and high stability, can reduce the energy consumption of the electrolyzed water reaction, improve the hydrogen production efficiency, maintain activity during long-term operation, and has excellent industrial application prospects.

[0030] Generally speaking, the structured electrolyzed water catalyst and its preparation method provided by the present invention significantly improve the catalyst performance and production efficiency through high loading design and rapid preparation process, and provide an efficient and low-cost solution for the field of hydrogen production by electrolyzing water. Description of the Drawings

[0031] Figure 1 It is a scanning electron microscope (SEM) image of the catalyst prepared in Example 1, with a scale of 500 μm.

[0032] Figure 2It is the linear sweep voltammetry (LSV) curve diagram of the catalyst prepared in Example 1. In the figure, a is the LSV curve of OER, and b is the LSV curve of HER.

[0033] Figure 3 It is the linear sweep voltammetry (LSV) curve diagram of the catalyst prepared in Example 2. In the figure, a is the LSV curve of OER, and b is the LSV curve of HER.

[0034] Figure 4 It is the linear sweep voltammetry (LSV) curve diagram of the catalyst prepared in Example 3. In the figure, a is the LSV curve of OER, and b is the LSV curve of HER.

[0035] Figure 5 It is the scanning electron microscope (SEM) image of the catalyst prepared in Example 4, with a scale of 500 μm.

[0036] Figure 6 It is the linear sweep voltammetry (LSV) curve diagram of the catalyst prepared in Example 4. In the figure, a is the LSV curve of OER, and b is the LSV curve of HER.

[0037] Figure 7 It is the linear sweep voltammetry (LSV) curve diagram of the catalyst prepared in Example 5. In the figure, a is the LSV curve of OER, and b is the LSV curve of HER. Detailed implementation mode

[0038] The preferred implementation modes of the present invention will be described in detail below in conjunction with examples. It should be understood that the following examples are given only for illustrative purposes and are not used to limit the scope of the present invention. Those skilled in the art can make various modifications and substitutions to the present invention without departing from the purpose and spirit of the present invention.

[0039] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels or prepared by conventional methods in the art. The nickel foam substrate used in the examples of the present invention is purchased from Shengnuonuo Energy Mall, with a surface density of 280 g / m 3 , and the porosity is 95%.

[0040] Example 1: Preparation of Ni-based high-loading structured electrolytic water catalyst Prepare a 50 ML ethanol solution containing 1.0 M nickel nitrate as the precursor solution (metal salt solution). After stirring evenly, add 5 ML of deionized water and 10 ML of 1,2-epoxybutane (the volume ratio of water to 1,2-epoxybutane is 1:2), and stir at room temperature for 30 minutes to form a uniform gel-like Ni-based precursor solution.

[0041] A 5 cm × 5 cm nickel foam substrate was ultrasonically cleaned with 3M HCl solution, deionized water, and ethanol for 15 minutes each to remove the surface oxide layer and impurities, and then dried under vacuum conditions of 50 °C and -0.1 MPa for 30 minutes. The clean nickel foam was immersed in the gel-like precursor solution for 10 minutes, and the active components were uniformly attached to the pore structure of the nickel foam by the confinement adsorption of the gel. The immersed nickel foam substrate was placed in a Joule heating device, and a thermal effect was generated through a DC power supply (voltage 10V, current 5A) to quickly dry and cure for 5 seconds, obtaining a preliminary sample. The obtained sample was placed in a tubular furnace, heated to 350 °C at a rate of 3 °C / minute under a hydrogen atmosphere, held for 3 hours, and then naturally cooled to obtain a Ni-based structured electrolysis water catalyst. Microscopic observation of this catalyst showed that the SEM image is shown in Figure 1 。

[0042] After measurement, the loading amount of the active components of this catalyst is 10.2 Mg / cm 2 . In a 1M KOH electrolyte solution, a three-electrode test system (Hg / HgO as the reference electrode and graphite as the counter electrode) was used for the hydrogen production reaction. The scanning rate was 5 mV / s, and the current density was 100 mA / cm 2 . When the overpotential of the oxygen evolution reaction (OER) was 319 mV and the overpotential of the hydrogen evolution reaction (HER) was 159 mV, and there was no obvious performance decay after continuous operation for 100 hours.

[0043] The linear sweep voltammetry (LSV) curve of this catalyst is shown in Figure 2 。

[0044] Example 2: Preparation of a CoMo-based high-loading structured electrolysis water catalyst A 50 mL ethanol solution containing 0.1M cobalt nitrate and 0.05M molybdenum chloride was prepared as the precursor solution. After stirring evenly, 2.5 mL of deionized water and 7.5 mL of 1,2-epoxybutane (the volume ratio of water to 1,2-epoxybutane is 1:3) were added, and the mixture was stirred at room temperature for 40 minutes to form a gel-like CoMo-based precursor solution.

[0045] After a 5 cm × 5 cm nickel foam substrate was cleaned and dried according to the method of Example 1, it was immersed in the prepared gel-like precursor solution for 15 minutes, and the confinement adsorption of the active components was realized by the viscosity of the gel and the three-dimensional pore structure of the nickel foam. The immersed nickel foam substrate was placed in a Joule heating device, and a DC power supply (voltage 12V, current 4A) was applied to quickly dry and cure for 8 seconds, obtaining a preliminary sample. The obtained sample was placed in a tubular furnace, heated to 400 °C at a rate of 1 °C / minute under an argon atmosphere, held for 2 hours, and then naturally cooled to obtain a CoMo-based structured electrolysis water catalyst.

[0046] The loading amount of the active component of this catalyst was measured to be 5.8 Mg / cm 2 . In a 1 M KOH electrolyte solution, a three-electrode test system (Hg / HgO as the reference electrode and graphite as the counter electrode) was used for the hydrogen production reaction. The scanning rate was 5 mV / s, and the current density was 100 mA / cm 2 . When the current density was 100 mA / cm, the overpotential of OER was 268 mV, and the overpotential of HER was 93 mV. The performance remained stable after continuous operation for 120 hours.

[0047] The linear sweep voltammetry (LSV) curve of this catalyst is shown in Figure 3 .

[0048] Example 3: Preparation of a FeNi-based structured electrolytic water catalyst A 50 mL ethanol solution containing 0.1 M iron nitrate and 0.1 M nickel nitrate was prepared as a precursor solution. After stirring evenly, 4 mL of deionized water and 16 mL of 1,2-epoxybutane (the volume ratio of water to 1,2-epoxybutane was 1:4) were added, and the mixture was stirred at room temperature for 50 minutes to form a gel-like FeNi-based precursor solution.

[0049] After a 5 cm × 5 cm nickel foam substrate was cleaned and dried according to the method of Example 1, it was immersed in the prepared gel-like precursor solution for 20 minutes to ensure that the active components were firmly attached through confined adsorption. The immersed nickel foam substrate was placed in a Joule heating device, and a DC power supply (voltage 15 V, current 6 A) was applied for rapid drying and curing for 10 seconds to obtain a preliminary sample. The obtained sample was placed in a tubular furnace and heated to 400 °C at a rate of 5 °C per minute in a mixed atmosphere of ammonia and nitrogen (volume ratio 1:3), held at this temperature for 1 hour, and then cooled naturally to obtain a FeNi-based structured electrolytic water catalyst.

[0050] The loading amount of the active component of this catalyst was measured to be 8.5 Mg / cm 2 . In a 1 M KOH electrolyte solution, a three-electrode test system (Hg / HgO as the reference electrode and graphite as the counter electrode) was used for the hydrogen production reaction. The scanning rate was 5 mV / s, and the current density was 100 mA / cm 2 . When the current density was 100 mA / cm, the overpotential of OER was 251 mV, and the overpotential of HER was 109 mV. The excellent performance was still maintained after continuous operation for 150 hours.

[0051] The linear sweep voltammetry (LSV) curve of this catalyst is shown in Figure 4 .

[0052] Example 4: Preparation of a Ru-based structured electrolytic water catalyst Prepare a 50 mL ethanol solution containing 2.0 M ruthenium chloride as the precursor solution. After stirring evenly, add 5 mL of deionized water and 25 mL of 1,2-epoxybutane (the volume ratio of water to 1,2-epoxybutane is 1:5), and stir at room temperature for 60 minutes to form a gel-like Ru-based precursor solution.

[0053] After cleaning and drying a 5 cm × 5 cm nickel foam substrate according to the method of Example 1, immerse it in the prepared gel-like precursor solution and soak for 20 minutes to achieve the attachment of high-concentration active components by confined adsorption. Place the immersed nickel foam in a Joule heating device, apply a DC power supply (voltage 15 V, current 8 A), and quickly dry and cure for 10 seconds to obtain a preliminary sample. Place the obtained sample in a tubular furnace, heat it to 200 °C at a rate of 2 °C / min under a nitrogen atmosphere, hold for 3 hours, and then cool naturally to obtain a Ru-based structured electrolytic water catalyst. Conduct microscopic observation on this catalyst, and the SEM image is shown in Figure 5 .

[0054] It is measured that the loading amount of the active component of this catalyst is 135.6 Mg / cm 2 . In a 1 M KOH electrolyte, a three-electrode test system (Hg / HgO as the reference electrode and graphite as the counter electrode) is used for the hydrogen production reaction. The scanning rate is 5 mV / s, and the current density is 100 mA / cm 2 When the OER overpotential is 271 mV and the HER overpotential is 89 mV, the performance is stable after continuous operation for 200 hours.

[0055] The linear sweep voltammetry (LSV) curve of this catalyst is shown in Figure 6 .

[0056] Example 5: Preparation of NiCuW-based structured electrolytic water catalyst Prepare a 50 mL ethanol solution containing 0.09 M nickel nitrate, 0.01 M copper nitrate, and 0.05 M tungsten chloride as the precursor solution. After stirring evenly, add 5 mL of deionized water and 5 mL of 1,2-epoxybutane (the volume ratio of water to 1,2-epoxybutane is 1:1), and stir at room temperature for 30 minutes to form a gel-like NiCuW precursor solution.

[0057] After cleaning and drying a 5 cm × 5 cm nickel foam substrate according to the method of Example 1, immerse it in the prepared gel-like precursor solution and soak for 15 minutes to make the active components attach by the confined adsorption of the gel. Place the immersed nickel foam in a Joule heating device, apply a DC power supply (voltage 8 V, current 3 A), and quickly dry and cure for 2 seconds to obtain a preliminary sample. Place the obtained sample in a tubular furnace, heat it to 450 °C at a rate of 4 °C / min under an ammonia atmosphere, hold for 1.5 hours, and then cool naturally to obtain a NiCuW-based structured electrolytic water catalyst.

[0058] The loading amount of the active component of this catalyst was measured to be 13.2 Mg / cm 2 . In a 1 M KOH electrolyte solution, a three-electrode test system (Hg / HgO as the reference electrode and graphite as the counter electrode) was used for hydrogen production reaction. The scanning rate was 5 mV / s and the current density was 100 mA / cm 2 . When the current density was 100 mA / cm², the overpotential of OER was 307 mV and the overpotential of HER was 67 mV. The performance was stable after continuous operation for 200 hours.

[0059] The linear sweep voltammetry (LSV) curve of this catalyst is shown in Figure 7 .

[0060] Comparative Example 1: Preparation without Joule heating drying A 50 mL ethanol solution containing 1.0 M nickel nitrate was prepared as a precursor solution. After stirring evenly, 5 mL of deionized water and 10 mL of 1,2-epoxybutane (the volume ratio of water to 1,2-epoxybutane was 1:2) were added, and the mixture was stirred at room temperature for 30 minutes to form a gel-like Ni-based precursor solution. A 5 cm × 5 cm nickel foam substrate was cleaned and dried according to the method of Example 1, and then immersed in the prepared gel-like precursor solution for 10 minutes. Omitting the Joule heating drying step, the infiltrated sample was directly placed in a tube furnace under hydrogen protection, heated to 350 °C at a rate of 3 °C per minute, and calcined for 3 hours to obtain the catalyst.

[0061] The loading amount of the active component of this catalyst was measured to be 2.1 Mg / cm 2 . In a 1 M KOH electrolyte solution, a three-electrode test system (Hg / HgO as the reference electrode and graphite as the counter electrode) was used for hydrogen production reaction. The scanning rate was 5 mV / s and the current density was 100 mA / cm 2 . When the current density was 100 mA / cm², the overpotential of OER was 350 mV and the overpotential of HER was 330 mV. Moreover, the active component significantly peeled off after operating for 50 hours and the performance decreased significantly.

[0062] Comparative Example 2: Preparation without gel-like precursor A 50 mL ethanol solution containing 0.1 M cobalt nitrate and 0.05 M molybdenum chloride was prepared as a precursor solution. Water and 1,2-epoxybutane were not added and the mixture was stirred evenly. A 5 cm × 5 cm nickel foam substrate was cleaned and dried according to the method of Example 1, and then immersed in the prepared solution for 15 minutes. The infiltrated nickel foam was placed in a Joule heating device, and a DC power supply (voltage 12 V, current 4 A) was applied to quickly dry and cure for 8 seconds. The obtained sample was placed in a tube furnace, heated to 400 °C at a rate of 1 °C per minute under an argon atmosphere, held for 2 hours and then cooled naturally to obtain the catalyst.

[0063] The loading amount of the active component of the catalyst was measured to be 5.6 Mg / cm 2 . In a 1 M KOH electrolyte, a three-electrode test system (Hg / HgO as the reference electrode and graphite as the counter electrode) was used for the hydrogen production reaction. The scanning rate was 5 mV / s and the current density was 100 mA / cm 2 . When the overpotential of OER was 340 mV and the overpotential of HER was 320 mV, the activity decreased significantly after running for 60 hours.

[0064] Comparative Example 3: Changing the ratio of water to 1,2-epoxybutane A 50 mL ethanol solution containing 1.0 M nickel nitrate was prepared as a precursor solution. After stirring evenly, 5 mL of deionized water and 50 mL of 1,2-epoxybutane (the volume ratio of water to 1,2-epoxybutane was 1:10) were added. After stirring at room temperature for 30 minutes, the solution formed an uneven gel and some precipitation occurred.

[0065] After a 5 cm × 5 cm nickel foam substrate was cleaned and dried according to the method of Example 1, it was immersed in the solution prepared in step (1) for 10 minutes. The immersed nickel foam was placed in a Joule heating device, and a DC power supply (voltage 10 V, current 5 A) was applied to quickly dry and cure for 5 seconds to obtain a preliminary sample. The obtained sample was placed in a tubular furnace and heated to 350 °C at a rate of 3 °C per minute in a hydrogen atmosphere, and then naturally cooled after holding for 3 hours to obtain the catalyst.

[0066] The loading amount of the active component of the catalyst was measured to be 3.5 Mg / cm 2 . In a 1 M KOH electrolyte, a three-electrode test system (Hg / HgO as the reference electrode and graphite as the counter electrode) was used for the hydrogen production reaction. The scanning rate was 5 mV / s and the current density was 100 mA / cm 2 . When the overpotential of the oxygen evolution reaction (OER) was 380 mV and the overpotential of the hydrogen evolution reaction (HER) was 289 mV, the activity decreased significantly after running for 80 hours.

[0067] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A method for preparing a catalyst, characterized in that, Comprising: (1) Dissolve a metal salt in ethanol to obtain a metal salt solution, and then fully mix it with water and 1,2-epoxybutane to obtain a precursor solution; The concentration of the metal salt in the metal salt solution is 0.01 - 2.0 M; The volume ratio of the total volume of the metal salt solution, water and 1,2-epoxybutane is 5:(1 - 3); The volume ratio of water and 1,2-epoxybutane is 1:(1 - 5); (2) Fully immerse a clean nickel foam substrate in the precursor solution prepared in step (1); (3) Use a Joule heating device to perform drying and curing treatments on the immersed nickel foam substrate obtained in step (2); the time for the drying and curing treatments is 1 - 10 seconds; (4) Perform heat treatment in an atmosphere, the temperature of the heat treatment is 200 - 500 °C, the time of the heat treatment is 0.5 - 3 hours, and the gas in the atmosphere includes one or more of argon, nitrogen, hydrogen, and ammonia.

2. The method according to claim 1, characterized in that, The metal salt is selected from one or more of nickel nitrate, cobalt nitrate, iron nitrate, copper nitrate, chromium nitrate, manganese nitrate, molybdenum chloride, tungsten chloride, ruthenium chloride, and iridium chloride.

3. The method according to claim 2, wherein In step (3), during the drying and curing treatments, the voltage of the Joule heating device is 8 - 15 V, and the current is 3 - 8 A.

4. The method according to any one of claims 1 to 3, characterized in that, In step (4), the heating rate during the heat treatment is 1 - 5 °C / minute.

5. The method according to any one of claims 1 to 3, characterized in that, In step (1), the time for full mixing is 30 - 60 minutes.

6. The method according to any one of claims 1-3, characterized in that In step (2), the time for full immersion is 10 - 20 minutes.

7. The method according to any one of claims 1 to 3, characterized in that, The cleaning method of the nickel foam substrate includes: sequentially ultrasonically cleaning with hydrochloric acid, water, and ethanol for 10 - 15 minutes, and then performing vacuum drying.

8. A catalyst, characterized in that, Prepared by the method according to any one of claims 1 - 7.

9. Use of the catalyst according to claim 8 in hydrogen production by electrolysis of water.

10. A method for hydrogen production, characterized in that, Including the step of electrolyzing water with the catalyst according to claim 8.

Images