Preparation process of multi-element catalytic electrode and multi-element catalytic electrode

Abstract

The invention discloses a preparation process of a multi-element catalytic electrode and the multi-element catalytic electrode, and relates to the technical field of hydrogen production. The preparation process comprises the following steps: selecting an electrode base material, and preparing a metal mixture; spraying the metal mixture to the surface of the electrode base material through a plasma spraying process; the electrode base material is etched through alkali liquor; cleaning the etched electrode base material, and carrying out drying treatment on the cleaned electrode base material; the etched electrode base material is put into a preset solution to be subjected to soaking treatment; carrying out heating reduction treatment on the soaked electrode base material in a reduction furnace, wherein the reduction furnace contains reducing gas and inert gas; after the heating time is reached at the heating temperature, the multi-element catalytic electrode is obtained; the multi-element catalytic electrode can produce hydrogen, and the surface of the multi-element catalytic electrode is provided with multi-element alloy. Low-energy-consumption water electrolysis hydrogen production can be achieved, the problem of oxidation falling caused by reverse current can be solved, and high-stability hydrogen production is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of energy materials, and in particular to a preparation process of a multi-component catalytic electrode and a multi-component catalytic electrode. Background Art

[0002] In the relevant technical fields, hydrogen energy has become an important energy source for addressing climate change and building a decarbonized society. Hydrogen energy (green hydrogen) and electricity (green electricity) will become inevitable choices. Global hydrogen energy has entered a new stage of rapid industrial development, and the popularity of the hydrogen energy industry continues to rise. The water electrolysis process is easy to industrialize due to its high efficiency and is the most promising method for hydrogen production.

[0003] At present, alkaline electrolyzers are the mainstream in China, with the characteristics of simple operation, high product purity, no pollution and economical raw material sources. Water electrolysis is to pass direct current through acidic or alkaline aqueous solution to decompose water, and hydrogen is released at the cathode, also known as the hydrogen evolution electrode, and oxygen is released at the anode, also known as the oxygen evolution electrode.

[0004] However, the efficiency of hydrogen production by alkaline electrolyzers is relatively low and the energy consumption is high. Summary of the invention

[0005] The embodiment of the present application provides a preparation process of a multi-catalytic electrode and a multi-catalytic electrode, which can realize low-energy electrolysis of water to produce hydrogen, and also solve the problem of oxidation shedding caused by reverse current, thereby realizing highly stable hydrogen production.

[0006] In a first aspect, the present application provides a method for preparing a multi-element catalytic electrode, wherein the steps of the method include:

[0007] Select electrode substrate and prepare metal mixture;

[0008] Spraying the metal mixture onto the surface of the electrode substrate by a plasma spraying process;

[0009] etching the electrode substrate by using an alkaline solution;

[0010] Cleaning and drying the etched electrode substrate;

[0011] The electrode substrate after etching is placed in a preset solution for immersion treatment; wherein the preset solution is a metal salt solution containing at least two elements, and the concentration of the preset solution is a preset concentration;

[0012] The electrode substrate after soaking is heated and reduced in a reduction furnace, wherein the reduction furnace contains reducing gas and inert gas;

[0013] After the heating time is reached at the heating temperature, a multi-component catalytic electrode is obtained; wherein the multi-component catalytic electrode is capable of producing hydrogen and has a multi-component alloy on the surface.

[0014] In some embodiments, the step of placing the etched electrode substrate into a preset solution for immersion treatment comprises:

[0015] Adding the preset solution into a container;

[0016] Putting the electrode substrate into the container and soaking it;

[0017] After the soaking time is reached, taking out the electrode substrate;

[0018] Drying the electrode substrate;

[0019] Wherein, during the above-mentioned soaking process, the temperature of the preset solution in the container is controlled within a preset temperature range.

[0020] In some embodiments, the preset concentration corresponding to the preset solution is 5%-30%;

[0021] The soaking time is 1 hour to 48 hours, and the preset temperature range is 30° C. to 90° C.

[0022] In some embodiments, the preset solution is an organic salt solution or an inorganic salt solution, and the salt solution contains at least two elements of nickel, molybdenum, aluminum, copper, iron, platinum, and gold.

[0023] In some embodiments, the metal mixture is a powder or alloy of nickel and an additional metal.

[0024] In some embodiments, the additional metal includes one or more of copper, molybdenum, gold, aluminum, cobalt, iron, platinum, and silver, and the weight ratio of nickel to the additional metal is a:b, wherein a=100, 10≤b≤100.

[0025] In some embodiments, the plasma spraying is one of atmospheric plasma spraying, vacuum plasma spraying, and supersonic spraying.

[0026] In some embodiments, the reducing gas is one or more of hydrogen, carbon monoxide, hydrogen sulfide, methane, or sulfur monoxide, and the inert gas is one or more of nitrogen, argon, or helium.

[0027] In some embodiments, the reducing gas and the inert gas cooperate to form a mixed gas, and the reducing gas accounts for 0.5%-80% of the mixed gas by volume;

[0028] The heating temperature is 100° C.-1200° C., and the heating time is 1 h-20 h.

[0029] In a second aspect, an embodiment of the present application provides a multi-component catalytic electrode, which is manufactured using the above-mentioned multi-component catalytic electrode preparation process.

[0030] Based on the preparation process of the multi-component catalytic electrode of the embodiment of the present application, the multi-component catalytic electrode prepared by the above process can make the hydrogen evolution overpotential lower than 70mV (under the test environment of η10mA), and the current density change of 1.5V start-stop test 1000 times is less than 10%, with better hydrogen evolution effect and stability, and can realize hydrogen evolution operation under lower overpotential, reduce hydrogen evolution requirements and energy consumption, and achieve the beneficial effect of reducing costs and increasing efficiency. This type of electrode has low energy consumption and good stability in the process of hydrogen production by electrolysis of water, and has great potential application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 It is a schematic diagram of the process of preparing a multi-element catalytic electrode in one embodiment of the present application;

[0033] Figure 2 This is a schematic diagram of the process of soaking the electrode substrate in one embodiment of the present application;

[0034] Figure 3 This is a schematic diagram of the principle structure of water electrolysis in one embodiment of the present application;

[0035] Figure 4 This is a cyclic voltammetry characterization diagram of a multi-component catalytic electrode prepared in one embodiment of the present application.

[0036] Reference numerals:

[0037] 100. electrolytic cell; 110. electrolysis of water; 200. hydrogen evolution electrode; 300. oxygen evolution electrode; 400. power supply. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0039] In existing technologies, hydrogen can be divided into three categories according to the amount of carbon emissions generated during the production process of hydrogen energy: "gray hydrogen", which will emit a large amount of carbon dioxide; "blue hydrogen" can achieve low-carbon hydrogen production; and "green hydrogen" uses renewable energy to electrolyze water to produce hydrogen, which theoretically does not produce carbon emissions, so it has a higher growth potential.

[0040] In the preparation process of hydrogen evolution electrode in the related art, the current catalytic electrode has poor stability and high hydrogen evolution overpotential, which is mainly reflected in the diaphragm and catalytic electrode, resulting in high energy consumption during use. Specifically, the catalysts used in the electrolyzer are mostly nickel-based, pure nickel mesh or nickel foam or highly active nickel-based catalysts sprayed on this substrate. The effect after conventional nickel-aluminum powder spraying is low in hydrogen evolution overpotential and high in energy consumption. Spraying alloy powder has poor stability. Catalysts include Raney nickel, activated nickel sulfide, nickel-molybdenum alloy or activated nickel-aluminum, etc.

[0041] The present application can achieve low hydrogen evolution overpotential and high stability by treating the spray electrode with a metal salt solution. After the salt solution treatment, the cracks of the spray can be healed to achieve high stability. At the same time, the residual salt can be reduced after thermal reduction to achieve surface multi-element alloy properties.

[0042] This application can realize low-energy consumption water electrolysis hydrogen production, and at the same time can solve the oxidation shedding problem caused by reverse current, and realize highly stable hydrogen production. This application has a simple process, and the cost is much lower than the foreign products with the same energy efficiency, which is easy to realize industrialization and has a high market value.

[0043] To solve the above technical problems, please refer to Figure 1-Figure 3 As shown, the first aspect of the present application proposes a preparation process of a multi-catalytic electrode, which can achieve low-energy consumption water electrolysis to produce hydrogen, and also solves the problem of oxidation shedding caused by reverse current, thereby achieving highly stable hydrogen production.

[0044] Reference Figure 1 In some embodiments of the present application, a preparation process of a multi-element catalytic electrode is provided, and the preparation process steps include:

[0045] Step S100: Selecting an electrode substrate and preparing a metal mixture;

[0046] In the above steps, preparation of the multi-catalytic electrode can be prepared. The electrode substrate is the reference material of the multi-catalytic electrode, and a suitable electrode substrate can be selected as needed. The metal mixture is the key material for the surface treatment of the electrode substrate. The metal mixture can be sprayed on the surface of the electrode substrate through the corresponding spraying process, and the metal mixture can be more stably attached to the outer surface of the electrode substrate by soaking, heating reduction, etc.

[0047] It should be noted that the electrode substrate of the present application can be a metal substrate, specifically a nickel-based substrate, a molybdenum-based substrate, a copper-based substrate, an iron-based substrate, etc. The present application is not limited to the above-mentioned substrates and is selected according to actual needs.

[0048] Step S200: spraying the metal mixture onto the surface of the electrode substrate by a plasma spraying process;

[0049] In the above steps, the metal mixture can be sprayed on the surface of the electrode substrate. The surface of the electrode substrate can be preliminarily treated so that enough metal can be sprayed on the surface of the electrode substrate, making it easier to form a multi-element alloy on the surface of the electrode substrate.

[0050] Step S300: etching the electrode substrate with an alkaline solution;

[0051] In the above steps, after etching the electrode substrate with an alkaline solution, the sprayed surface of the etched area can be removed at the position where the electrode substrate needs to be connected to the circuit to ensure the effectiveness of the electrode substrate.

[0052] Step S400: cleaning and drying the etched electrode substrate;

[0053] In the above steps, the electrode substrate after etching is cleaned to reduce the residues generated during the etching process. After drying, the next step of soaking treatment can be facilitated.

[0054] Step S500: placing the etched electrode substrate into a preset solution for immersion treatment; wherein the preset solution is a metal salt solution containing at least two elements, and the concentration of the preset solution is a preset concentration;

[0055] In the above steps, the spray coating can be treated with a metal salt solution to heal cracks in the spray coating, improve the stability of the spray coating, and reduce or even avoid the problem of oxidation and shedding of the spray coating caused by reverse current. In addition, the electrode substrate can be treated with a metal salt solution to achieve a low hydrogen evolution overpotential, making the electrode substrate more stable.

[0056] Step S600: heating and reducing the soaked electrode substrate in a reduction furnace, wherein the reduction furnace contains reducing gas and inert gas;

[0057] In the above steps, the electrode material can be subjected to a thermal reduction treatment. After the thermal reduction treatment, the residual salt can be reduced to achieve surface multi-element alloy properties.

[0058] Step S700: After the heating time reaches the heating temperature, a multi-component catalytic electrode is obtained; wherein the multi-component catalytic electrode is capable of producing hydrogen and has a multi-component alloy on the surface.

[0059] In the above steps, the reducing gas can be fully reduced on the surface of the electrode substrate through a certain heating temperature and heating time, thereby improving the bonding stability between the entire electrode substrate and the corresponding metal mixture, allowing the multi-component alloy to better adhere to the electrode substrate, and obtaining the final required multi-component catalytic electrode.

[0060] Based on the above-mentioned embodiments of the present application, the multi-catalytic electrode prepared by the above-mentioned process can make the hydrogen evolution overpotential lower than 70mV (under the test environment of η10mA), and the current density change after 1000 times of 1.5V start-stop test is less than 10%. That is to say, the preparation process of the present application can make a multi-catalytic electrode with a hydrogen evolution overpotential lower than 70mV, and the performance of the multi-catalytic electrode can be adjusted according to the ratio of materials and process parameters to obtain more types of multi-catalytic electrodes, such as: a multi-catalytic electrode with a hydrogen evolution overpotential lower than 65mV; a multi-catalytic electrode with a hydrogen evolution overpotential lower than 45mV; a multi-catalytic electrode with a hydrogen evolution overpotential lower than 35mV, and the corresponding multi-catalytic electrode can be manufactured according to actual needs.

[0061] The multi-element catalytic electrode of the present application has better hydrogen evolution effect and stability, can realize hydrogen evolution operation under lower overpotential, reduce hydrogen evolution requirements and energy consumption, and achieve the beneficial effect of reducing costs and increasing efficiency. This type of electrode has low energy consumption and good stability in the process of electrolyzing water to produce hydrogen, and has great potential application value.

[0062] It should be noted that the preparation process of the present application is designed for the hydrogen evolution electrode. Specifically, in the process of electrolysis of water, the electrolysis of water is to pass direct current through an acidic or alkaline aqueous solution to decompose water, and hydrogen is precipitated at the cathode, also known as the hydrogen evolution electrode, and oxygen is precipitated at the anode, also known as the oxygen evolution electrode. The multi-component catalytic electrode of the present application is a hydrogen evolution electrode, so it is in the cathode position in the corresponding circuit, and the cathode material and the anode material are relatively arranged, and a suitable metal substrate can be selected as needed.

[0063] Reference Figure 2 In some embodiments of the present application, the step of placing the etched electrode substrate into a preset solution for immersion treatment (step S500) includes:

[0064] Step S510: adding a preset solution into the container;

[0065] In the above steps, the container can contain a preset solution to prepare for the immersion of the electrode substrate.

[0066] Step S520: placing the electrode substrate into the container for soaking;

[0067] In the above steps, the electrode substrate may be immersed. Specifically, the entire electrode substrate may be immersed below the preset solution level, or a portion of the electrode substrate may be immersed as required.

[0068] Step S530: after the soaking time is reached, taking out the electrode substrate;

[0069] In the above steps, after the immersion time, the electrode substrate can be immersed more fully, the cracks of the sprayed layer can be healed as much as possible, the stability of the sprayed layer can be improved, and the problem of oxidation and shedding of the sprayed layer caused by reverse current can be reduced or even avoided.

[0070] Step S540: drying the electrode substrate;

[0071] In the above steps, the liquid residue on the electrode substrate can be reduced by drying to prepare for thermal reduction. If necessary, the electrode substrate after immersion can also be cleaned with a corresponding salt solution.

[0072] Wherein, during the above-mentioned soaking process, the temperature of the preset solution in the container is controlled within a preset temperature range.

[0073] Based on the above-mentioned embodiments of the present application, by immersing the electrode substrate in a preset solution within a preset stability range for a sufficient time, the cracks in the spray coating can be better healed, the stability of the spray coating can be improved, the defective rate of the electrode substrate can be reduced, and the overall production cost can be reduced.

[0074] In some embodiments of the present application, the preset concentration corresponding to the preset solution is 5%-30%;

[0075] The soaking time is 1h-48h, and the preset temperature range is 30℃-90℃.

[0076] Based on the above-mentioned embodiments of the present application, the above-mentioned structure can control the concentration of the preset solution to 5%-30% to ensure the soaking effect. The soaking time can be adaptively adjusted according to changes in the preset concentration, solution element type, etc., and the preset stability corresponding to the solution temperature can also be adjusted as needed. For example, when the preset concentration is 30%, the soaking time of the preset solution is 24h, and the temperature is controlled at about 60°C; when the preset concentration is 20%, the soaking time of the preset solution is 24h, and the temperature is controlled at about 75°C. The specific situation is adaptively adjusted according to the time requirements, and the above is only an exemplary description.

[0077] In some embodiments of the present application, the preset solution is an organic salt solution or an inorganic salt solution, and the salt solution contains at least two elements of nickel, molybdenum, aluminum, copper, iron, platinum, and gold.

[0078] Based on the above embodiments of the present application, the above exemplary description of the categories of preset solutions, in actual production and processing, the corresponding preset solutions can be selected as needed. For example: copper sulfate (5%), aluminum molybdate (25%) solution; aluminum molybdate (20%) solution; cobalt sulfate (5%), copper molybdate (40%) solution, etc.

[0079] In some embodiments of the present application, the metal mixture is a powder or alloy of nickel and an additional metal.

[0080] Based on the above embodiments of the present application, the metal mixture is a spraying material for spraying the electrode substrate, which can be a mixed powder structure of various single substance powders or a corresponding alloy. Different spraying processes can select a more suitable metal mixture.

[0081] In some embodiments of the present application, the additional metal includes one or more of copper, molybdenum, gold, aluminum, cobalt, iron, platinum, and silver, and the weight ratio of nickel to the additional metal is a:b, where a=100, 10≤b≤100.

[0082] Based on the above embodiments of the present application, the additional metal refers to a metal compounded onto the main metal nickel. The weight ratio of the above nickel to the additional metal is a range ratio. That is, the maximum ratio of nickel to the additional metal can be 10:1, and the nickel content is ten times the total of the additional metal; the minimum ratio of nickel to the additional metal can be 1:1, and the nickel content is the same as the total content of the additional metal. A suitable weight ratio can be selected as needed.

[0083] In some embodiments of the present application, plasma spraying is one of atmospheric plasma spraying, vacuum plasma spraying, and supersonic spraying.

[0084] Based on the above embodiments of the present application, the spraying of the metal mixture in the present application can adopt the above three plasma spraying methods, which can be selected according to the specific needs. The spraying method of the present application is not limited to the above three methods, and other suitable spraying methods can also be selected according to the needs.

[0085] In some embodiments of the present application, the reducing gas is one or more of hydrogen, carbon monoxide, hydrogen sulfide, methane or sulfur monoxide, and the inert gas is one or more of nitrogen, argon or helium.

[0086] Based on the above embodiments of the present application, the reducing gas is a gas with a reducing effect. One or more of the above reducing gases can be used as needed. Reduction is a relative reaction. A specific metal combination may not produce a reducing reaction with one of the above gases. Under the corresponding metal, the corresponding gas needs to be excluded. Inert gas can improve the stability of the reduction reaction process, ensure the stability of the reduction reaction, and avoid safety hazards such as sudden changes in air pressure and explosions.

[0087] In some embodiments of the present application, the reducing gas and the inert gas are combined to form a mixed gas, and the reducing gas accounts for 0.5%-80% of the volume of the mixed gas;

[0088] The heating temperature is 100°C-1200°C, and the heating time is 1h-20h.

[0089] Based on the above-mentioned embodiments of the present application, the volume proportion of the reducing gas in the total can be selected as needed. The heating temperature is an external condition for the reduction reaction. A specific reduction reaction requires a corresponding heating temperature. The heating temperature can also affect the reaction rate of the reduction reaction. Different mixed gases and different objects to be reduced also require different temperatures. A more suitable heating stability can be obtained under a limited number of experiments, so as to select a suitable heating temperature as needed. The heating time can ensure the sufficiency of the reduction reaction. The reduction reaction can be made more sufficient through sufficient heating time. As much residual salt as possible can be reduced to achieve surface multi-element alloy performance, ensure the stability of the multi-element alloy, and remove unnecessary elements.

[0090] This application is further described with three embodiments as examples, and the specific embodiments are as follows:

[0091] Example 1: The multi-catalytic electrode prepared in this example has a hydrogen evolution overpotential of 65±5 mV (η10 mA), and a current density decay of 5±1% after 1000 start-stop tests at 1.5 V.

[0092] The plasma spraying process in this embodiment adopts atmospheric plasma spraying, the metal mixture is a mixture of nickel powder and aluminum powder, the electrode substrate is a nickel mesh, and the surface of the nickel mesh needs to be sandblasted and polished. The etching solution is 15% sodium hydroxide. The metal salt solution is a solution of copper sulfate (5%) and aluminum molybdate (25%). The mixed gas is a mixed gas of hydrogen and nitrogen, and the proportion of hydrogen is 10%.

[0093] Among them, the spraying conditions of the atmospheric plasma spraying process are as follows: the ratio of argon to hydrogen is 5:1, the spraying power is 30KW, the spraying distance is 20cm, the spraying speed is 250m / s, the powder feeding amount is 150g / min, the particle sizes of nickel powder and aluminum powder are in the range of 10 to 50 microns in diameter, respectively. The particle sizes of nickel powder and aluminum powder can be the same or different, and can be selected according to needs.

[0094] The specific preparation process is as follows:

[0095] Step 1: Use atmospheric plasma spraying to spray nickel powder and aluminum powder onto the surface of a 60-mesh nickel mesh. The spraying amount of nickel powder and aluminum powder is 300g / m 2 ;

[0096] Step 2: Place the sprayed nickel mesh in a 15% sodium hydroxide solution at 40°C for 12 hours, then take it out and clean the surface with pure water, and blow dry it after cleaning;

[0097] Step 3, placing the dried nickel mesh in a solution containing copper sulfate (5%) and aluminum molybdate (25%) at a temperature of 60°C, taking it out after 24 hours, and directly drying the nickel mesh if it is not clear;

[0098] Step 4, place the above nickel mesh in a vacuum furnace, evacuate to -0.1mPa, then flush in nitrogen, evacuate again, and then pass a mixed gas of hydrogen and nitrogen, with hydrogen accounting for 10%, heat to 100°C for hydrogen reduction for 5 hours, and you can get a multi-catalytic electrode containing nickel, molybdenum, aluminum, and copper on the surface.

[0099] The multi-catalytic electrode obtained by the above process steps has a hydrogen evolution overpotential of 65±5 mV, and a current density decay of 5±1% after 1000 times of 1.5V start-stop test.

[0100] The characterization data of the multi-element catalytic electrode in this embodiment are specifically shown in the following test table:

[0101]

[0102] Reference Figure 4 , shows the cyclic voltammetry characterization diagram of the multi-catalytic electrode prepared in this example.

[0103] Example 2: The multi-component catalytic electrode prepared in this example has a hydrogen evolution overpotential of 45±5 mV (η10 mA), and a current density decay of 7±1% after 1000 start-stop tests at 1.5 V.

[0104] The plasma spraying process in this embodiment adopts atmospheric plasma spraying, the metal mixture is a mixture of nickel-molybdenum alloy powder and aluminum powder, the electrode substrate is a nickel mesh, and the surface of the nickel mesh needs to be sandblasted and polished. The etching solution is 20% sodium hydroxide. The metal salt solution is a solution of aluminum molybdate (20%). The mixed gas is a mixed gas of hydrogen and nitrogen, and the proportion of hydrogen is 20%.

[0105] Among them, the spraying conditions of the atmospheric plasma spraying process are that the ratio of argon and hydrogen is 5:1, the spraying power is 35KW, the spraying distance is 20cm, the spraying speed is 250m / s, the powder feeding amount is 150g / min, the diameter range of the nickel-molybdenum alloy powder is 5-70 microns, the nickel: molybdenum weight ratio is 55:45, the diameter range of the aluminum powder is 5-30 microns, and the nickel-molybdenum: aluminum weight ratio is 75:25. The particle sizes of the nickel-molybdenum alloy powder and the aluminum powder can be the same or different, and the specific selection is based on the needs.

[0106] The specific preparation process is as follows:

[0107] Step 1: Use atmospheric plasma spraying to spray nickel-molybdenum alloy powder and aluminum powder onto the surface of the nickel sheet, with a spraying amount of 350g / m2;

[0108] Step 2: Place the sprayed nickel mesh in a 20% potassium hydroxide solution at 70°C for 24 hours, then take it out and clean the surface with pure water, and blow dry it after cleaning;

[0109] Step 3: Place the dried nickel mesh in a solution containing aluminum molybdate (20%) at a temperature of 75°C, place for 24 hours, then take it out and dry the nickel mesh directly if it is not clear;

[0110] Step 4: Place the nickel mesh in a vacuum furnace, evacuate to -0.1 mPa, then inject argon, evacuate again, and then introduce a mixture of hydrogen and nitrogen, with hydrogen accounting for 20%. Heat to 150°C for hydrogen reduction for 15 hours to obtain a multi-catalytic electrode containing nickel-molybdenum alloy inside and nickel, molybdenum and aluminum on the surface.

[0111] Example 3: The multi-catalytic electrode prepared in this example has a hydrogen evolution overpotential of 35±5 mV (η10 mA), and a current density decay of 9±1% after 1000 start-stop tests at 1.5 V.

[0112] The plasma spraying process in this embodiment adopts vacuum plasma spraying, the metal mixture is a mixture of nickel powder and aluminum powder, the electrode substrate is a nickel mesh, and the surface of the nickel mesh needs to be sandblasted and polished. The etching solution is a 30% sodium hydroxide and 10% potassium sodium tartrate solution. The metal salt solution is a solution of cobalt sulfate (5%) and copper molybdate (40%). The mixed gas is a mixed gas of hydrogen and helium, and the proportion of hydrogen is 5%.

[0113] The spraying conditions of the vacuum plasma spraying process are as follows: the ratio of argon to hydrogen is 5:1, the spraying power is 30KW, the spraying distance is 20cm, the spraying speed is 250m / s, the powder feeding amount is 150g / min, and the spraying vacuum is -0.1mPa. The particle sizes of nickel powder and aluminum powder are in the range of 10 to 50 microns in diameter, respectively. The particle sizes of nickel powder and aluminum powder can be the same or different, and can be selected according to needs.

[0114] The specific preparation process is as follows:

[0115] Step 1: Use vacuum plasma spraying to spray nickel powder and aluminum powder onto the surface of a 60-mesh nickel mesh, with a spraying amount of 300g / m2;

[0116] Step 2: Place the sprayed nickel mesh in a 30% sodium hydroxide and 10% sodium potassium tartrate solution at 70°C for 12 hours, then take it out and clean the surface with pure water, and blow dry it after cleaning;

[0117] Step 3: Place the dried nickel mesh in a solution containing cobalt sulfate (5%) and copper molybdate (40%) at 60°C, place for 24 hours and then take it out. If the nickel mesh is not clear, dry it directly.

[0118] Step 4: Place the nickel mesh in a vacuum furnace, evacuate to -0.1 mPa, then flush in nitrogen, evacuate again, and then introduce a mixture of hydrogen and helium, with the hydrogen ratio being 5%. Heat to 300°C for hydrogen reduction for 6 hours to obtain a multi-catalytic electrode containing nickel, molybdenum, copper, and cobalt on the surface.

[0119] In a second aspect, an embodiment of the present application provides a multi-component catalytic electrode, which is made by the above-mentioned preparation process of the multi-component catalytic electrode.

[0120] Based on the above-mentioned embodiments of the present application, the multi-catalytic electrode prepared by the above-mentioned process can make the hydrogen evolution overpotential lower than 70mV (under the test environment of η10mA), and the current density change after 1000 times of 1.5V start-stop test is less than 10%. That is to say, the preparation process of the present application can make a multi-catalytic electrode with a hydrogen evolution overpotential lower than 70mV, and the performance of the multi-catalytic electrode can be adjusted according to the ratio of materials and process parameters to obtain more types of multi-catalytic electrodes, such as: a multi-catalytic electrode with a hydrogen evolution overpotential lower than 65mV; a multi-catalytic electrode with a hydrogen evolution overpotential lower than 45mV; a multi-catalytic electrode with a hydrogen evolution overpotential lower than 35mV, and the corresponding multi-catalytic electrode can be manufactured according to actual needs.

[0121] The multi-element catalytic electrode of the present application has better hydrogen evolution effect and stability, can realize hydrogen evolution operation under lower overpotential, reduce hydrogen evolution requirements and energy consumption, and achieve the beneficial effect of reducing costs and increasing efficiency. This type of electrode has low energy consumption and good stability in the process of electrolyzing water to produce hydrogen, and has great potential application value.

[0122] Reference Figure 3, shows a schematic diagram of the principle of the electrolysis device in the present application, the electrolysis device includes an electrolytic cell 100, electrolyzed water 110, a hydrogen evolution electrode 200, an oxygen evolution electrode 300 and a power supply 400, wherein the electrolytic cell 100 has a cavity for containing the electrolyzed water 110, the hydrogen evolution electrode 200, the oxygen evolution electrode 300 and the power supply 400 form an electrolysis circuit, the hydrogen evolution electrode 200 and the oxygen evolution electrode 300 at least partially extend into the electrolyzed water 110, after power is turned on, the hydrogen evolution electrode 200 in the electrolyzed water 110 can precipitate hydrogen, and the oxygen evolution electrode 300 in the electrolyzed water 110 can precipitate oxygen. The multi-component catalytic electrode in the present application is the hydrogen evolution electrode 200.

[0123] It should be noted that electrolyzed water 110 is liquid water or aqueous solution that is electrolyzed. Among them, if the object of electrolysis is liquid water, what is generated is hydrogen and oxygen. The conductivity of liquid water itself is too small, and the electrolysis efficiency is poor during electrolysis. At this time, a strong electrolyte can be added to the water as needed to enhance the conductivity. In order to simply increase the conductivity without causing unnecessary reactions, Na2SO4, H2SO4, NaOH, etc. can usually be added to the water. It should be noted that the addition of NaCl can also make the electrolysis phenomenon occur significantly, but what is generated is H2 and Cl2 chlorine. At this time, the object of electrolysis is not water, but a salt-water mixture. In the case of hydrogen production as the main method, NaCl can also be added to the electrolyzed water as needed to improve the electrolysis efficiency.

[0124] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate an orientation or position relationship based on the orientation or position relationship shown in the drawings, it is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0125] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A process for preparing a multi-element catalytic electrode, characterized in that: The preparation process steps include: Select electrode substrate and prepare metal mixture; Spraying the metal mixture onto the surface of the electrode substrate by a plasma spraying process; etching the electrode substrate by using an alkaline solution; Cleaning and drying the etched electrode substrate; The electrode substrate after etching is placed in a preset solution for immersion treatment; wherein the preset solution is a metal salt solution containing at least two elements, and the concentration of the preset solution is a preset concentration; The electrode substrate after soaking is heated and reduced in a reduction furnace, wherein the reduction furnace contains reducing gas and inert gas; After the heating time is reached at the heating temperature, a multi-component catalytic electrode is obtained; wherein the multi-component catalytic electrode is capable of producing hydrogen and has a multi-component alloy on the surface.

2. The process for preparing a multi-element catalytic electrode according to claim 1, characterized in that: The step of placing the etched electrode substrate into a preset solution for immersion treatment comprises: Adding the preset solution into a container; Putting the electrode substrate into the container and soaking it; After the soaking time is reached, taking out the electrode substrate; Drying the electrode substrate; Wherein, during the above-mentioned soaking process, the temperature of the preset solution in the container is controlled within a preset temperature range.

3. The process for preparing a multi-element catalytic electrode according to claim 2, characterized in that: The preset concentration corresponding to the preset solution is 5%-30%; The soaking time is 1 hour to 48 hours, and the preset temperature range is 30° C. to 90° C.

4. The process for preparing a multi-component catalytic electrode according to any one of claims 1 to 3, characterized in that: The preset solution is an organic salt solution or an inorganic salt solution, and the salt solution contains at least two elements of nickel, molybdenum, aluminum, copper, iron, platinum, and gold.

5. The process for preparing a multi-element catalytic electrode according to claim 1, characterized in that: The metal mixture is a powder or alloy of nickel and an additional metal.

6. The process for preparing a multi-element catalytic electrode according to claim 5, characterized in that: The additional metal includes one or more of copper, molybdenum, gold, aluminum, cobalt, iron, platinum, and silver, and the weight ratio of nickel to the additional metal is a:b, wherein a=100, 10≤b≤100.

7. The process for preparing a multi-element catalytic electrode according to claim 1, characterized in that: The plasma spraying is one of atmospheric plasma spraying, vacuum plasma spraying and supersonic spraying.

8. The process for preparing a multi-element catalytic electrode according to claim 1, characterized in that: The reducing gas is one or more of hydrogen, carbon monoxide, hydrogen sulfide, methane or sulfur monoxide, and the inert gas is one or more of nitrogen, argon or helium.

9. The process for preparing a multi-element catalytic electrode according to claim 8, characterized in that: The reducing gas and the inert gas cooperate to form a mixed gas, and the reducing gas accounts for 0.5%-80% of the mixed gas by volume; The heating temperature is 100° C.-1200° C., and the heating time is 1 h-20 h.

10. A multi-component catalytic electrode, characterized in that: The multi-catalytic electrode is made by the preparation process of the multi-catalytic electrode according to any one of claims 1 to 9.

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