Electrolytic water hydrogen evolution composite catalytic electrode, preparation method and application thereof

Abstract

The application discloses an electrolytic water hydrogen evolution composite catalytic electrode and a preparation method thereof. The composite catalytic electrode comprises a nickel base, a composite catalyst layer loaded on the nickel base, and a metal oxide protective layer coated on the surface of the composite catalyst layer; wherein the composite catalyst layer comprises platinum, ruthenium, palladium noble metal catalysts and catalytic additives, the metal oxide protective layer is a nano-porous metal oxide layer, and the metal oxide is one or more of valve metal oxides and rare earth metal oxides. The electrolytic water hydrogen evolution composite catalytic electrode comprises a platinum, ruthenium, palladium and additive composite catalyst layer and a metal oxide protective layer coated on the outside; the metal components in the composite catalyst layer can be stably combined with the metal base, the metal oxide protective layer is similar in structure to the oxides in the composite catalyst layer, and can be firmly covered on the surface of the composite catalyst layer; so that the composite catalytic electrode can exhibit high electrolytic water hydrogen evolution catalytic activity, high structural stability, long-term stability, strong anti-reverse polarity and strong anti-deposition capacity.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen production by water electrolysis, specifically relating to a composite catalytic electrode for hydrogen evolution by water electrolysis, its preparation method, and its application. Background Technology

[0002] Currently, humanity faces energy and environmental pollution problems caused by the overexploitation of fossil fuels. Hydrogen, as an ideal energy storage carrier, has advantages such as high energy density, cleanliness, zero pollution, and zero carbon emissions. As a promising and efficient clean energy source, current hydrogen production is mainly constrained by environmentally unfriendly methods such as coal-to-hydrogen production. In contrast, water electrolysis for hydrogen production is not only clean and environmentally friendly but also produces high-purity hydrogen, making it a promising next-generation large-scale hydrogen production method.

[0003] Hydrogen production through water electrolysis converts green electricity generated from wind and solar power into chemical energy stored in hydrogen gas, facilitating convenient energy transportation and ensuring a continuous supply. Currently, commercially viable alkaline water electrolysis for hydrogen production primarily utilizes nickel-mesh composite catalytic electrodes with a 30wt% KOH electrolyte, operating at 80-90℃ under a specific cell voltage. However, the widely used nickel-mesh composite catalytic electrodes operate mainly at low current densities, and their intrinsic catalytic activity in water electrolysis is not ideal. This results in a large overpotential during electrolysis, increasing power consumption and leading to excessively high costs. Therefore, there is an urgent need for water electrolysis catalytic materials with higher catalytic activity to reduce hydrogen production costs. Platinum, with its strong catalytic ability and good corrosion resistance, can be applied to high-current-density water electrolysis environments for hydrogen production. For example, patent CN112877728B prepared a platinum-carbon supported composite catalytic electrode for electrolytic water production on nickel foam by spraying and calcination; patent CN114016067B prepared a low-platinum-nitrogen-sulfur co-doped nickel phosphide self-supporting composite catalytic electrode for electrolytic water production by hydrothermal growth, phosphating-nitriding-sulfurization, and rapid ultraviolet-assisted growth; and patent CN115627493A prepared a platinum-doped composite catalytic electrode by hydrothermal growth of nickel hydroxide support on a nickel mesh and electrochemical deposition of platinum; these are used to improve the catalytic activity of hydrogen production by electrolytic water production.

[0004] However, due to the scarcity and high price of platinum group elements in the Earth's crust, their widespread use in industrial applications is limited. Therefore, reducing platinum usage and improving its efficiency are pressing problems that need to be addressed. Existing technologies typically employ electroplating to prepare catalytic electrodes, which often results in poor adhesion between the plating layer and the substrate, affecting plating stability and platinum utilization efficiency. Furthermore, electroplating involves a large initial investment and high equipment maintenance costs. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems in the prior art by providing a method for preparing a hydrogen evolution composite catalytic electrode suitable for large-scale production of water electrolysis, as well as the composite catalytic electrode prepared by this method. The method can efficiently, conveniently, and cost-effectively prepare a hydrogen evolution composite catalytic electrode with low precious metal content. Furthermore, the composite catalytic electrode has a low hydrogen evolution potential, high stability, strong anti-reverse polarity, and strong anti-deposition properties, which can meet the application requirements of industrial high current density water electrolysis.

[0006] The present invention provides a composite catalytic electrode for water electrolysis and hydrogen evolution, comprising a nickel substrate, a catalyst layer supported on the nickel substrate, and a protective layer covering the surface of the composite catalytic layer; wherein the composite catalyst layer comprises a noble metal catalyst, and the protective layer is a nanoporous metal oxide layer, wherein the metal oxide is one or more of valve metal oxides and rare earth metal oxides.

[0007] According to one embodiment of the present invention, the precious metal is one or more of platinum, ruthenium, and palladium; preferably, the composite catalyst layer further includes a catalytic promoter.

[0008] According to another embodiment of the present invention, the metal oxide is one or more of titanium oxide, cerium oxide, zirconium oxide, aluminum oxide, yttrium oxide, niobium oxide, tantalum oxide and lanthanum oxide.

[0009] According to another embodiment of the present invention, the total loading of the noble metal catalyst and the catalyst promoter is 0.01-20 mg / cm³. 2 The preferred concentration is 0.05-1.0 mg / cm³. 2 The molar ratio of the noble metal to the catalyst promoter is 1:1-1000:1; the loading of the metal oxide is 0.01-0.2 mg / cm³. 2 The preferred concentration is 0.02-0.05 mg / cm³. 2 .

[0010] According to another embodiment of the present invention, the catalyst is a metallic element, alloy or oxide selected from one or more of Ni, Au, Ag, Zn, Ti, Ce, Mo, Co, Fe, Cu and La.

[0011] According to another embodiment of the present invention, the nickel matrix is ​​a nickel mesh, a nickel alloy mesh, nickel foam, or a nickel foam alloy.

[0012] Another aspect of the present invention provides a method for preparing a composite catalytic electrode for hydrogen evolution in water electrolysis, comprising: adding a stabilizer to a noble metal catalyst precursor compound solution to form a catalyst solution, or adding a catalytic promoter precursor compound and the stabilizer to the noble metal catalyst precursor compound solution to form a composite catalyst solution; coating the catalyst solution onto the surface of a nickel substrate and then sintering it to form a composite catalyst layer; providing a metal oxide precursor solution, coating it onto the surface of the composite catalyst layer, and then sintering it to form the protective layer.

[0013] According to one embodiment of the present invention, the stabilizer is one or more of hydrochloric acid, sulfuric acid, acetic acid, nitric acid, and citric acid.

[0014] According to another embodiment of the present invention, the sintering step for forming the composite catalyst layer includes: sintering at 200-400°C for 10 min-10 h in air, an inert atmosphere or a reducing atmosphere, and then calcining at 400-600°C for 30 min-12 h; preferably, sintering at 300-350°C for 10 min-2 h, and then calcining at 450-550°C for 30 min-2 h.

[0015] According to another embodiment of the present invention, the sintering step of forming the protective layer includes: calcining at 200-600°C for 5 min-12 h under air or inert atmosphere conditions; preferably, calcining at 300-500°C for 30 min-2 h.

[0016] According to another embodiment of the present invention, the nickel substrate is subjected to a roughening treatment.

[0017] In another aspect, the present invention provides a water electrolysis hydrogen evolution device, using the above-mentioned water electrolysis hydrogen evolution composite catalytic electrode as the cathode.

[0018] This invention provides a composite catalytic electrode for hydrogen evolution in water electrolysis. The catalyst layer of the composite catalytic electrode is coated with a protective layer. Since the composite catalytic layer contains a noble metal main catalyst, a catalyst promoter, and a metal oxide, the noble metal main catalyst and catalyst promoter can bond with the metal substrate to form a stable structure. The metal oxide has a similar structure to the outer oxide protective layer, allowing the oxide protective layer to stably cover the surface of the composite catalytic layer. This results in the composite catalytic electrode exhibiting high catalytic activity for hydrogen evolution in water electrolysis, high structural stability, long-term stability, strong resistance to reverse polarity, and strong resistance to deposition. Compared with electroplating methods for preparing noble metal electrodes and methods using noble metal catalysts adhered to a nickel substrate with a binder to prepare a hydrogen evolution composite catalytic electrode, this method is simpler to operate, has a higher utilization rate of noble metals, and exhibits high structural stability, strong resistance to reverse polarity, and strong resistance to deposition, making it of significant industrial application value. Attached Figure Description

[0019] Figure 1The image shows a SEM image of the cerium oxide-coated platinum-nickel composite catalytic electrode prepared in Example 1.

[0020] Figure 2 The graphs show the electrolysis voltage versus current density of the cerium oxide-coated platinum-nickel electrode prepared in Example 1, the sandblasted nickel mesh in Comparative Example 1, and the platinum-nickel composite catalytic electrode prepared in Comparative Example 2.

[0021] Figure 3 The graph shows the change in electrolysis voltage over electrolysis time for the cerium oxide-coated platinum-nickel electrode prepared in Example 1, the sandblasted nickel mesh in Comparative Example 1, and the platinum-nickel composite catalytic electrode prepared in Comparative Example 2.

[0022] Figure 4 This is a SEM image of the electrolytic reaction of the sandblasted nickel mesh composite catalytic electrode in Comparative Example 1.

[0023] Figure 5 This is a SEM image of the platinum-nickel composite catalytic electrode prepared in Comparative Example 2 after the electrolysis reaction.

[0024] Figure 6 The image shows a SEM image of the cerium oxide-coated platinum-nickel composite catalytic electrode prepared in Example 1 after the electrolysis reaction.

[0025] Figure 7 This is a SEM image of the cerium oxide-coated platinum-cerium composite catalytic electrode prepared in Example 2.

[0026] Figure 8 The graph shows the change in electrolysis voltage as a function of current density for the cerium oxide-coated platinum-cerium composite catalytic electrode prepared in Example 2.

[0027] Figure 9 The graph shows the change in electrolysis voltage over electrolysis time for the cerium oxide-coated platinum-cerium composite catalytic electrode prepared in Example 2.

[0028] Figure 10 This is a SEM image of the cerium oxide-coated platinum-cerium composite catalytic electrode prepared in Example 2 after the electrolysis reaction.

[0029] Figure 11 This is a SEM image of the titanium oxide-coated platinum-ruthenium composite catalytic electrode prepared in Example 3.

[0030] Figure 12 The graph shows the change in electrolysis voltage as a function of current density for the titanium oxide-coated platinum-ruthenium composite catalytic electrode prepared in Example 3.

[0031] Figure 13 The graph shows the change in electrolysis voltage over electrolysis time for the titanium oxide-coated platinum-ruthenium composite catalytic electrode prepared in Example 3.

[0032] Figure 14 This is a SEM image of the titanium oxide-coated platinum-ruthenium composite catalytic electrode prepared in Example 3 after electrolysis.

[0033] Figure 15 This is a SEM image of the zirconium oxide-coated platinum-iron composite catalytic electrode prepared in Example 4.

[0034] Figure 16 The graph shows the change in electrolysis voltage as a function of current density for the zirconium oxide-coated platinum-iron composite catalytic electrode prepared in Example 4.

[0035] Figure 17 The graph shows the change in electrolysis voltage over electrolysis time for the zirconium oxide-coated platinum-iron composite catalytic electrode prepared in Example 4.

[0036] Figure 18 This is a SEM image of the zirconium oxide-coated platinum-iron composite catalytic electrode prepared in Example 4 after the electrolysis reaction.

[0037] Figure 19 This is a SEM image of the alumina-coated platinum-ruthenium-cerium composite catalytic electrode prepared in Example 5.

[0038] Figure 20 The graph shows the change in electrolysis voltage as a function of current density for the alumina-coated platinum-ruthenium-cerium composite catalytic electrode prepared in Example 5.

[0039] Figure 21 The graph shows the change in electrolysis voltage over electrolysis time for the alumina-coated platinum-ruthenium-cerium composite catalytic electrode prepared in Example 5.

[0040] Figure 22 This is a SEM image of the alumina-coated platinum-ruthenium-cerium composite catalytic electrode prepared in Example 5 after the electrolysis reaction.

[0041] Figure 23 Photograph of the cerium oxide-coated platinum-ruthenium-nickel composite catalytic electrode prepared in Example 6.

[0042] Figure 24 This is a SEM image of the cerium oxide-coated platinum-ruthenium-nickel composite catalytic electrode prepared in Example 6.

[0043] Figure 25 The graph shows the change in electrolysis voltage as a function of current density for the cerium oxide-coated platinum-ruthenium-nickel composite catalytic electrode prepared in Example 6.

[0044] Figure 26 The graph shows the change in electrolysis voltage over electrolysis time for the cerium oxide-coated platinum-ruthenium-nickel composite catalytic electrode prepared in Example 6.

[0045] Figure 27 This is a SEM image of the cerium oxide-coated platinum-ruthenium-nickel composite catalytic electrode prepared in Example 6 after the electrolysis reaction. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0047] The electrolytic hydrogen evolution composite catalytic electrode for water electrolysis of the present invention includes a nickel substrate, a composite catalyst layer supported on the nickel substrate, and a protective layer covering the surface of the catalyst layer. The composite catalyst layer includes a noble metal catalyst, and the protective layer is a nanoporous metal oxide layer, wherein the metal oxide is one or more of valve metal oxides and rare earth metal oxides. Since the composite catalyst layer contains a noble metal main catalyst, a catalyst promoter, and a metal oxide, the noble metal main catalyst and catalyst promoter can bond with the metal substrate to form a stable structure. The metal oxide has a similar structure to the outer oxide protective layer, allowing the oxide protective layer to stably cover the surface of the composite catalyst layer. The nanoporous metal oxide layer attached to the outside of the noble metal catalyst can ensure the catalytic performance of the noble metal catalyst while preventing direct contact between the noble metal catalyst and the electrolyte, preventing impurities from depositing on the catalyst layer surface. Furthermore, the protective layer prevents catalyst detachment, improving the structural stability and service life of the catalyst layer.

[0048] The noble metal in the composite catalyst layer can be any catalyst suitable for hydrogen evolution through water electrolysis, such as one or more of platinum, ruthenium, and palladium. Preferably, the noble metal catalyst includes platinum. The composite catalyst layer may also include a catalytic promoter. When a catalytic promoter is included, the amount of noble metal used can be reduced to achieve the same catalytic performance. In the composite catalytic electrode, the total loading of the noble metal catalyst and catalytic promoter relative to the apparent area of ​​the composite catalytic electrode (the unit of loading in this patent is relative to the apparent area of ​​the electrode) is 0.01-20 mg / cm². 2 The preferred concentration is 0.05-1.0 mg / cm³. 2 The molar ratio of the noble metal catalyst to the catalyst promoter is 1:1 to 1000:1. The catalyst promoter can be one or more elemental metals, alloys, or oxides selected from Ni, Au, Ag, Zn, Ti, Ce, Mo, Co, Fe, Cu, and La.

[0049] The metal oxide in the protective layer can be one or more of titanium oxide, cerium oxide, zirconium oxide, aluminum oxide, yttrium oxide, niobium oxide, tantalum oxide, and lanthanum oxide. In the composite catalytic electrode, the loading of the metal oxide in the protective layer is 0.01-0.2 mg / cm³. 2 The preferred concentration is 0.02-0.05 mg / cm³. 2 .

[0050] In the composite catalytic electrode, the nickel matrix is ​​preferably a nickel mesh, a nickel alloy mesh, nickel foam, or a nickel foam alloy.

[0051] The composite catalytic electrode for hydrogen evolution through water electrolysis of this invention is prepared by a chemical pyrolysis method. The preparation method may include: adding a stabilizer to a solution of a noble metal catalyst precursor compound to form a catalyst solution, or adding a catalyst precursor compound and a stabilizer to the solution to form a catalyst solution; coating the catalyst solution onto the surface of a nickel substrate and then sintering it to form a composite catalyst layer; providing a metal oxide precursor solution, coating it onto the surface of the catalyst layer, and then sintering it to form a metal oxide protective layer.

[0052] Before forming the catalyst solution, the noble metal catalyst solution can be prepared by any suitable method. Taking platinum as an example, a platinum precursor compound solution can be prepared, using chloroplatinic acid, potassium chloroplatinate, tetraammineplatinum nitrate, platinum acetylacetonate, etc. When the noble metal is another noble metal catalyst, the corresponding precursor compound can be used. The solvent can be water or a mixture of water and an organic solvent. The organic solvent can be alcohols, ethers, esters, etc., such as methanol, ethanol, isopropanol, n-butanol, ethyl acetate, etc., and the ratio of water to organic solvent can be adjusted arbitrarily. The concentration of the noble metal catalyst precursor compound solution is 0.01-6.0 mol / L, preferably 0.1-1.0 mol / L. A stabilizer is added to the precursor compound solution to form the catalyst solution. When the catalyst solution also contains a catalytic promoter, the catalytic promoter and stabilizer are added to the noble metal catalyst precursor compound solution. The catalyst promoter can be a precursor compound of promoters such as Ni, Au, Ag, Zn, Ti, Ce, Mo, Co, Fe, Cu, and La. The molar ratio of noble metal catalyst to promoter is 1:1-1000:1, preferably 10:1-100:1. The stabilizer can be hydrochloric acid, sulfuric acid, acetic acid, nitric acid, or citric acid. The molar ratio of platinum to stabilizer is 1:1-200:1.

[0053] Then, the composite catalyst solution is coated onto the nickel substrate surface. The coating method can be any suitable manner, such as brushing, spraying, roller coating, dip coating, or printing, preferably automated spraying and brushing methods. Optionally, a drying step is then included. Drying methods can include air drying at room temperature, oven drying at 30-200°C, preferably drying at 50-100°C. Of course, "optionally" means it may or may not be included. A sintering process is then performed. The sintering process can be sintering at 200-400°C for 10 min-10 h, followed by calcination at 400-600°C for 30 min-12 h. Preferably, sintering at 300-350°C for 10 min-2 h, followed by calcination at 450-550°C for 30 min-2 h. The sintering process is carried out in air, an inert atmosphere (e.g., nitrogen), or a reducing atmosphere (e.g., hydrogen), preferably calcination under air conditions. Finally, a cooling process may also be included. Cooling methods can be air cooling, room temperature cooling, or condensation cooling, preferably air cooling. The above-described coating, optionally drying, and sintering processes can be repeated 1 to 50 times, preferably 2 to 8 times. By repeating the above-described coating, optionally drying, and sintering processes once or multiple times, the catalyst can achieve the desired loading.

[0054] After forming the composite catalyst layer, a protective layer is applied. First, a metal oxide precursor solution is prepared. This metal oxide precursor solution can be a salt solution of titanium, cerium, zirconium, aluminum, yttrium, niobium, tantalum, lanthanum, etc. The concentration is 0.01-2 mol / L, preferably 0.1-0.5 mol / L. Then, the solution is coated onto the surface of the catalyst layer. The coating method can be brushing, spraying, roller coating, dip coating, or printing, preferably automatic spraying and automatic brushing methods. After coating, a drying step can optionally be performed. The drying conditions are the same as those described above. Then, sintering is performed, calcined at 200-600°C for 5 min-12 h under air or an inert atmosphere (e.g., nitrogen), preferably calcined at 300-500°C for 30 min-2 h. After sintering, a nanoporous metal oxide layer is obtained. Finally, a cooling process may also be included. The cooling method can be air cooling, room temperature cooling, or condensation cooling, preferably air cooling. The above-described coating, optionally drying, and sintering processes can be repeated 1-10 times, preferably 1-4 times. By repeating the above-described coating, optionally drying, and sintering processes once or multiple times, the metal oxide can achieve the desired loading amount.

[0055] The above steps yielded a composite catalytic electrode for hydrogen evolution in water electrolysis. This electrode was prepared via a chemical pyrolysis method, involving coating a noble metal-based composite precursor solution onto a nickel substrate, optionally drying, calcining and pyrolyzing, and then coating with a protective layer. The resulting composite catalytic electrode exhibits high catalytic activity for hydrogen evolution in water electrolysis, high structural stability, long-term stability, strong resistance to reverse polarity, and strong resistance to deposition. Compared to electroplating and the use of noble metal catalysts adhered to a nickel substrate with a binder, this method is simpler to operate, has higher utilization of noble metals, and demonstrates high structural stability, strong resistance to reverse polarity, and strong resistance to deposition, making it of significant industrial application value.

[0056] In addition to the steps mentioned above, other auxiliary steps may be included, such as cleaning, drying, and roughening treatment of the nickel substrate. Roughening the nickel substrate can improve the adhesion between the catalyst layer and the protective layer and the substrate. The treatment process may involve selecting a substrate such as nickel mesh, nickel alloy mesh, nickel foam, or nickel foam alloy, and then pre-treating the substrate. The pre-treatment process includes: sandblasting the nickel substrate using a sandblasting machine, preferably an automatic sandblasting machine; ultrasonic treatment to remove corundum particles from the substrate surface; preparing an acidic solution such as hydrochloric acid, sulfuric acid, nitric acid, or acetic acid to etch the sandblasted nickel substrate and remove highly active nickel particles from the surface; washing with water and drying to obtain a roughened nickel substrate, which is then leveled using a roller press. When the nickel substrate is a nickel mesh or nickel alloy mesh, a plain or twill mesh with a mesh size of 10-500 and a wire diameter of 0.03-4 mm can be used, preferably a plain nickel mesh with a mesh size of 20-80 and a wire diameter of 0.1-0.5 mm. The sandblasting power of the sandblasting machine is 5-50kW, preferably 10-20kW; the sandblasting time is 5min-2h, preferably 10-40min. The corundum used for sandblasting is grade 24, 46, 60, or 80, preferably 46 and 60. Sandblasting treatment includes single-sided or double-sided sandblasting of the nickel substrate, preferably double-sided sandblasting. The concentration of the acid etching solution is 0.005mol / L-2.0mol / L, preferably 0.02mol / L-0.2mol / L. The etching time is 10min-24h, preferably 1h-4h.

[0057] The present invention also discloses a water electrolysis hydrogen evolution device, which uses the above-mentioned water electrolysis hydrogen evolution composite catalytic electrode as the cathode.

[0058] The present invention is further described below through specific examples. However, these examples are merely exemplary and do not constitute any limitation on the scope of protection of the present invention. Unless otherwise specified, the reagents, materials, and instruments used in the following embodiments and comparative examples are commercially available.

[0059] Example 1

[0060] A 46-mesh plain nickel mesh was selected as the substrate. An automatic sandblasting machine with No. 60 corundum and a power of 15kW was used to sandblast the nickel mesh for 30 minutes. The mesh was then ultrasonically treated for 1 hour to remove the corundum particles on the surface. Then, a 0.2 mol / L hydrochloric acid solution was prepared and used to etch the sandblasted nickel mesh for 1 hour to remove the highly reactive Ni particles on the surface. After washing with water and drying, a rough nickel mesh substrate was obtained.

[0061] A 0.05 mol / L aqueous solution of chloroplatinic acid was prepared, and then nickel chloride additive was added, with a platinum to nickel molar ratio of 5:1. Hydrochloric acid stabilizer was also added, with a platinum to hydrochloric acid molar ratio of 10:1. The mixture was thoroughly mixed to obtain a platinum-nickel precursor solution. The platinum-nickel precursor was coated onto a nickel mesh surface using an automated spraying method. After drying in an oven at 100℃, it was calcined at 300℃ for 2 hours in air. This spraying-drying-calcination cycle was repeated 5 times. Finally, it was solidified at 500℃ for 5 hours and cooled to room temperature. The platinum-nickel loading was 0.4 mg / cm³. 2 .

[0062] A 0.02 mol / L cerium nitrate protective layer solution was prepared and coated onto the surface of a platinum-nickel catalyst layer using an automated spraying method. The layer was then calcined at 450°C for 2 hours in air. This spraying-calcination cycle was repeated twice, resulting in a cerium oxide protective layer loading of 0.05 mg / cm³. 2 A cerium oxide-coated platinum-nickel composite catalytic electrode (approximately 100 cm²) was prepared. 2 ), Figure 1 The SEM images show that the composite catalytic electrode has a smooth surface structure.

[0063] Comparative Example 1

[0064] This comparative example is compared with Example 1, except that no platinum-nickel catalyst is coated on the nickel mesh surface; instead, a sandblasted nickel mesh is used directly as the cathode for water electrolysis. A 46-mesh plain-weave nickel mesh is selected as the substrate, and an automatic sandblasting machine with No. 60 corundum and a power of 15kW is used to sandblast the nickel mesh for 30 minutes. Ultrasonic treatment for 1 hour removes the corundum particles from the surface. Then, a 0.2 mol / L hydrochloric acid solution is prepared and used to etch the sandblasted nickel mesh for 1 hour to remove the highly active Ni particles from the surface. After washing with water and drying, a rough nickel mesh composite catalytic electrode (approximately 100 cm²) is obtained. 2 ).

[0065] Comparative Example 2

[0066] This comparative example is compared with Example 1, except that a cerium oxide protective layer is not coated on the surface of the platinum-nickel composite catalytic electrode for use as the cathode in water electrolysis. A 46-mesh plain nickel mesh is selected as the substrate, and an automatic sandblasting machine with No. 60 corundum and a power of 15kW is used to sandblast the nickel mesh for 30 minutes. Ultrasonic treatment for 1 hour removes the corundum particles on the surface, and then a 0.2 mol / L hydrochloric acid solution is prepared to etch the sandblasted nickel mesh for 1 hour to remove the highly active Ni particles on the surface. After washing with water and drying, a rough nickel mesh substrate is obtained.

[0067] A 0.05 mol / L aqueous solution of chloroplatinic acid was prepared, and then nickel chloride was added, with a platinum to nickel molar ratio of 5:1. Hydrochloric acid stabilizer was also added, with a platinum to hydrochloric acid molar ratio of 10:1. The mixture was thoroughly mixed to obtain a platinum-nickel precursor solution. The platinum-nickel precursor was coated onto a nickel mesh surface using an automated spraying method. After drying in an oven at 100°C, it was calcined at 300°C for 2 hours in air. This spraying-drying-calcination cycle was repeated 5 times. Finally, it was solidified at 500°C for 5 hours and cooled to room temperature to obtain a platinum-nickel composite catalytic electrode (approximately 100 cm² in area). 2 The platinum-nickel loading was 0.4 mg / cm³. 2 .

[0068] Performance testing

[0069] Test method: A two-chamber electrolytic cell was used. The cathodes were the cerium oxide-coated platinum-nickel composite catalytic electrode prepared in Example 1, the sandblasted nickel mesh composite catalytic electrode prepared in Comparative Example 1, and the platinum-nickel composite catalytic electrode prepared in Comparative Example 2. The anode was a nickel mesh electrode, and the diaphragm was a composite diaphragm. The working area of ​​the anode and cathode electrodes was 10 cm². 2 Two composite catalytic electrodes were loaded onto each electrode, and a six-chamber electrolytic cell was used for comparative testing. During the test, a peristaltic pump was used to introduce electrolyte into the electrolytic cell. A 30wt% KOH aqueous solution was introduced into the anode and cathode at a flow rate of 150 rpm / min, and the test temperature was 80℃. (1) The test current density was 200 mA / cm². 2 400mA / cm 2 600mA / cm 2 800mA / cm 2 1000mA / cm 2 (2) Test at 1000mA / cm 2 Stability under high current density for 500 hours was tested, and the surface deposition was observed using SEM after the test to compare the anti-deposition performance; (3) Test at 600 mA / cm 2 Anti-reverse polarity performance under current density was tested by electrolysis for 1 hour, shutdown for 1 hour, electrolysis for 1 hour, shutdown for 1 hour, repeating this process 200 times, and comparing the changes in electrolysis voltage.

[0070] Test results: When the cathode is a cerium oxide-coated platinum-nickel composite catalytic electrode (Example 1), the current density is 200 mA / cm². 2 -1000mA / cm 2 The total water splitting voltage was between 1.60V and 1.99V, while when the cathode was a nickel mesh composite catalytic electrode (Comparative Example 1), the total water splitting voltage was between 1.94V and 2.41V. The cerium oxide-coated platinum-nickel composite catalytic electrode reduced energy consumption by approximately 17.5% compared to the nickel mesh electrode (see...). Figure 2 ), and at 1000mA / cm 2 After operating at high current density for 500 hours, the total water splitting voltage remained at approximately 2.0V, while the voltage of the platinum-nickel composite catalytic electrode in Comparative Example 2 increased to 2.18V, and the voltage of the nickel mesh electrode in Comparative Example 1 increased to 2.83V (see...). Figure 3 The comparison shows that the cerium oxide-coated platinum-nickel composite catalytic electrode of this invention exhibits higher catalytic activity and longer-term stability in water electrolysis compared to the nickel mesh electrode, thus improving the lifespan of the composite catalytic electrode and reducing energy consumption. After 500 hours of electrolysis at high current density, a large number of particles were deposited on the surface of the nickel mesh electrode compared to Comparative Example 1 (SEM image shown). Figure 4 In Comparative Example 2, some large particles were deposited on the surface of the platinum-nickel composite catalytic electrode (SEM image shown). Figure 5 In Example 1, only a small number of particles were deposited on the surface of the cerium oxide-coated platinum-nickel electrode (SEM image shown). Figure 6 This indicates that the composite catalytic electrode has strong anti-deposition ability. After 200 repeated electrolysis-shutdown tests, the electrolysis voltage maintenance rate of Example 1 was 95.5%, while that of Comparative Example 1 was 78.3% and that of Comparative Example 2 was 86.8%, indicating that the composite catalytic electrode has strong anti-reverse polarity ability.

[0071] Example 2

[0072] A 46-mesh plain nickel mesh was selected as the substrate. An automatic sandblasting machine with No. 46 corundum and a power of 15kW was used to sandblast the nickel mesh for 45 minutes. The mesh was then ultrasonically treated for 1 hour to remove the corundum particles on the surface. Then, a 0.2 mol / L hydrochloric acid solution was prepared and used to etch the sandblasted nickel mesh for 1 hour to remove the highly reactive Ni particles on the surface. After washing with water and drying, a rough nickel mesh substrate was obtained.

[0073] A 0.1 mol / L chloroplatinic acid solution in water / ethanol was prepared, and then cerium nitrate additive was added, with a platinum to cerium molar ratio of 5:2. Simultaneously, nitric acid stabilizer was added, with a platinum to nitric acid molar ratio of 10:1. The mixture was thoroughly mixed to obtain a platinum-cerium precursor solution. The platinum-cerium precursor was coated onto a nickel mesh surface by brushing, dried in an oven at 100°C, and then calcined at 300°C for 2 hours under a nitrogen atmosphere. This brushing-drying-calcination process was repeated three times. Finally, the solution was solidified at 500°C for 5 hours and cooled to room temperature. The platinum-cerium loading was 0.5 mg / cm³.2 .

[0074] A 0.02 mol / L cerium nitrate protective layer solution was prepared and then coated onto the surface of a platinum-cerium catalyst layer by brushing. The layer was then calcined at 450°C for 2 hours in air. This brushing-calcination process was repeated twice, resulting in a cerium oxide protective layer loading of 0.05 mg / cm³. 2 A cerium oxide-coated platinum-cerium composite catalytic electrode (approximately 100 cm²) was prepared. 2 ), Figure 7 The SEM images show that the composite catalytic electrode has a smooth surface structure.

[0075] Performance testing

[0076] Test method: A two-chamber electrolytic cell was used. The cathode was the cerium oxide-coated platinum-cerium composite catalytic electrode prepared in Example 2, the anode was a nickel mesh electrode, and the diaphragm was a composite diaphragm. The working area of ​​the anode and cathode electrodes was 10 cm². 2 The test was conducted using a 6-compartment electrolytic cell. The average value of the cell voltages was taken as the electrolytic voltage. During the test, a peristaltic pump was used to introduce electrolyte into the electrolytic cell. A 30wt% KOH aqueous solution was introduced into the anode and cathode at a flow rate of 150 rpm / min, and the test temperature was 80℃. (1) The test current density was 200 mA / cm². 2 400mA / cm 2 600mA / cm 2 800mA / cm 2 1000mA / cm 2 (2) Test at 1000mA / cm 2 Stability under high current density for 500 hours was tested, and the surface deposition was observed using SEM after the test to compare the anti-deposition performance; (3) Test at 600 mA / cm 2 Anti-reverse polarity performance under current density was tested by electrolysis for 1 hour, shutdown for 1 hour, electrolysis for 1 hour, shutdown for 1 hour, repeating this process 200 times, and comparing the changes in electrolysis voltage.

[0077] Test results: When the cathode is a cerium oxide-coated platinum-cerium composite catalytic electrode (Example 2), the current density is 200 mA / cm². 2 -1000mA / cm 2 The voltage for complete water decomposition is between 1.65V and 2.04V (see...). Figure 8 ), and at 1000mA / cm 2 After operating at high current density for 500 hours, the total water splitting voltage can still be maintained at approximately 2.05V (see...). Figure 9As can be seen, the cerium oxide-coated platinum-cerium composite catalytic electrode of the present invention exhibits high catalytic activity and long-term stability in water electrolysis, improving the service life of the composite catalytic electrode and reducing energy consumption. After electrolysis at high current density for 500 hours, only a small amount of particles were deposited on the surface of the cerium oxide-coated platinum-cerium electrode of Example 2 (SEM image shown). Figure 10 This indicates that the composite catalytic electrode has strong anti-deposition ability. After 200 repeated electrolysis-shutdown tests, the electrolysis voltage maintenance rate of the composite catalytic electrode in Example 2 was 95.8%, indicating that the composite catalytic electrode has strong anti-reverse polarity ability.

[0078] Example 3

[0079] A 46-mesh plain nickel mesh was selected as the substrate. An automatic sandblasting machine with No. 46 corundum and a power of 15kW was used to sandblast the nickel mesh for 45 minutes. The mesh was then ultrasonically treated for 1 hour to remove the corundum particles on the surface. Then, a 0.2 mol / L hydrochloric acid solution was prepared and used to etch the sandblasted nickel mesh for 1 hour to remove the highly reactive Ni particles on the surface. After washing with water and drying, a rough nickel mesh substrate was obtained.

[0080] A 0.1 mol / L chloroplatinic acid ethanol solution was prepared, and then ruthenium chloride was added, with a platinum to ruthenium molar ratio of 10:1. Hydrochloric acid stabilizer was also added, with a platinum to hydrochloric acid molar ratio of 10:1. The mixture was thoroughly mixed to obtain a platinum-ruthenium precursor solution. The platinum-ruthenium precursor was coated onto a nickel mesh surface using an automated spraying method. After drying in an oven at 100°C, it was calcined at 300°C for 2 hours in air. This spraying-drying-calcination process was repeated three times. Finally, it was solidified at 500°C for 5 hours and cooled to room temperature. The platinum-ruthenium loading was 0.55 mg / cm³. 2 .

[0081] A 0.02 mol / L tetrabutyl titanate protective layer solution was prepared and then coated onto the surface of a platinum-ruthenium catalyst layer using an automated spraying method. The layer was then calcined at 450°C for 2 hours in air. This spraying-calcination cycle was repeated twice, resulting in a titanium dioxide protective layer loading of 0.04 mg / cm³. 2 A titanium oxide-coated platinum-ruthenium composite catalytic electrode (approximately 100 cm²) was prepared. 2 ), Figure 11 The SEM images show that the prepared composite catalytic electrode has a smooth surface structure.

[0082] Performance testing

[0083] Test method: A two-chamber electrolytic cell was used. The cathode was the titanium oxide-coated platinum-ruthenium composite catalytic electrode prepared in Example 3, the anode was a nickel mesh electrode, and the diaphragm was a composite diaphragm. The working area of ​​the anode and cathode electrodes was 10 cm². 2The test was conducted using a 6-compartment electrolytic cell. The average value of the cell voltages was taken as the electrolytic voltage. During the test, a peristaltic pump was used to introduce electrolyte into the electrolytic cell. A 30wt% KOH aqueous solution was introduced into the anode and cathode at a flow rate of 150 rpm / min, and the test temperature was 80℃. (1) The test current density was 200 mA / cm². 2 400mA / cm 2 600mA / cm 2 800mA / cm 2 1000mA / cm 2 (2) Test at 1000mA / cm 2 Stability under high current density for 500 hours was tested, and the surface deposition was observed using SEM after the test to compare the anti-deposition performance; (3) Test at 600 mA / cm 2 Anti-reverse polarity performance under current density was tested by electrolysis for 1 hour, shutdown for 1 hour, electrolysis for 1 hour, shutdown for 1 hour, repeating this process 200 times, and comparing the changes in electrolysis voltage.

[0084] Test results: When the cathode is a titanium oxide-coated platinum-ruthenium composite catalytic electrode (Example 3), the current density is 200 mA / cm². 2 -1000mA / cm 2 The voltage for complete water decomposition is between 1.58V and 1.95V. Figure 12 ), and at 1000mA / cm 2 After operating at high current density for 500 hours, the total water splitting voltage can still be maintained at approximately 1.95V (see...). Figure 13 As can be seen, the titanium oxide-coated platinum-ruthenium composite catalytic electrode of the present invention exhibits high catalytic activity and long-term stability in water electrolysis, improving the service life of the composite catalytic electrode and reducing energy consumption. After electrolysis at high current density for 500 hours, only a small amount of particles were deposited on the surface of the titanium oxide-coated platinum-ruthenium electrode in Example 3 (SEM image shown). Figure 14 This indicates that the composite catalytic electrode has strong anti-deposition ability. After 200 repeated electrolysis-shutdown tests, the electrolysis voltage maintenance rate of the composite catalytic electrode in Example 3 was 95.3%, indicating that the composite catalytic electrode has strong anti-reverse polarity ability.

[0085] Example 4

[0086] A 46-mesh plain nickel mesh was selected as the substrate. An automatic sandblasting machine with No. 46 corundum and a power of 15kW was used to sandblast the nickel mesh for 45 minutes. The mesh was then ultrasonically treated for 1 hour to remove the corundum particles on the surface. Then, a 0.2 mol / L hydrochloric acid solution was prepared and used to etch the sandblasted nickel mesh for 1 hour to remove the highly reactive Ni particles on the surface. After washing with water and drying, a rough nickel mesh substrate was obtained.

[0087] A 0.05 mol / L potassium chloroplatate solution in aqueous solution / isopropanol was prepared, followed by the addition of ferric chloride as an additive, with a platinum to iron molar ratio of 5:1. Hydrochloric acid as a stabilizer was also added, with a platinum to hydrochloric acid molar ratio of 10:1. The mixture was thoroughly mixed to obtain a platinum-iron precursor solution. The platinum-iron precursor was coated onto a nickel mesh surface using a roller coating method. After drying in an oven at 100°C, it was calcined at 300°C for 2 hours in air. This roller coating-drying-calcination process was repeated twice. Finally, it was solidified at 500°C for 5 hours and cooled to room temperature. The platinum-iron loading was 0.1 mg / cm³. 2 .

[0088] A 0.02 mol / L zirconium nitrate protective layer solution was prepared and then coated onto the surface of a platinum-iron catalyst layer by roller coating. The layer was calcined at 500°C for 2 hours in air. This roller coating-calcination cycle was repeated once, resulting in a zirconium oxide protective layer loading of 0.02 mg / cm³. 2 A zirconium oxide-coated platinum-iron composite catalytic electrode (approximately 100 cm²) was prepared. 2 ), Figure 15 The SEM images show that the prepared composite catalytic electrode has a smooth surface structure.

[0089] Performance testing

[0090] Test method: A two-chamber electrolytic cell was used. The cathode was the zirconium oxide-coated platinum-iron composite catalytic electrode prepared in Example 4, the anode was a nickel mesh electrode, and the diaphragm was a composite diaphragm. The working area of ​​the anode and cathode electrodes was 10 cm². 2 The test was conducted using a 6-compartment electrolytic cell. The average value of the cell voltages was taken as the electrolytic voltage. During the test, a peristaltic pump was used to introduce electrolyte into the electrolytic cell. A 30wt% KOH aqueous solution was introduced into the anode and cathode at a flow rate of 150 rpm / min, and the test temperature was 80℃. (1) The test current density was 200 mA / cm². 2 400mA / cm 2 600mA / cm 2 800mA / cm 2 1000mA / cm 2 (2) Test at 1000mA / cm 2 Stability under high current density for 500 hours was tested, and the surface deposition was observed using SEM after the test to compare the anti-deposition performance; (3) Test at 600 mA / cm 2 Anti-reverse polarity performance under current density was tested by electrolysis for 1 hour, shutdown for 1 hour, electrolysis for 1 hour, shutdown for 1 hour, repeating this process 200 times, and comparing the changes in electrolysis voltage.

[0091] Test results: When the cathode is a zirconium oxide-coated platinum-iron composite catalytic electrode (Example 4), the current density is 200 mA / cm². 2 -1000mA / cm2 The voltage for complete water decomposition is between 1.75V and 2.16V. Figure 16 ), and at 1000mA / cm 2 After operating at high current density for 500 hours, the total water splitting voltage can still be maintained at approximately 2.18V (see...). Figure 17 As can be seen, the zirconia-coated platinum-iron composite catalytic electrode of the present invention exhibits high catalytic activity and long-term stability in water electrolysis, improving the service life of the composite catalytic electrode and reducing energy consumption. After electrolysis at high current density for 500 hours, only a small amount of particles were deposited on the surface of the zirconia-coated platinum-iron electrode of Example 4 (SEM image shown). Figure 18 This indicates that the composite catalytic electrode has strong anti-deposition ability. After 200 repeated electrolysis-shutdown tests, the electrolysis voltage maintenance rate in Example 4 was 95.2%, indicating that the composite catalytic electrode has strong anti-reverse polarity ability.

[0092] Example 5

[0093] A 46-mesh plain nickel mesh was selected as the substrate. An automatic sandblasting machine with No. 46 corundum and a power of 20kW was used to sandblast the nickel mesh for 45 minutes. The mesh was then ultrasonically treated for 1 hour to remove the corundum particles on the surface. Then, a 0.2 mol / L hydrochloric acid solution was prepared and used to etch the sandblasted nickel mesh for 1 hour to remove the highly reactive Ni particles on the surface. After washing with water and drying, a rough nickel mesh substrate was obtained.

[0094] A 0.05 mol / L aqueous solution of chloroplatinic acid was prepared, and then ruthenium chloride and cerium nitrate additives were added, with a platinum:ruthenium:cerium molar ratio of 10:1:1. Hydrochloric acid stabilizer was also added, with a platinum:hydrochloric acid molar ratio of 5:1. The mixture was thoroughly mixed to obtain a platinum-ruthenium-cerium precursor solution. The platinum-ruthenium-cerium precursor was coated onto a nickel mesh surface using an automated brush coating method. After drying in an oven at 80°C, it was calcined at 300°C for 2 hours in air. This brush coating-drying-calcination cycle was repeated once, and finally, it was solidified at 500°C for 5 hours and cooled to room temperature. The platinum-ruthenium-cerium loading was 0.04 mg / cm³. 2 .

[0095] A 0.02 mol / L aluminum chloride protective layer solution was prepared and then coated onto the surface of a platinum-ruthenium-cerium catalyst layer using an automated brushing method. The layer was then calcined at 450°C for 2 hours under air conditions, resulting in an alumina protective layer loading of 0.01 mg / cm³. 2 An alumina-coated platinum-ruthenium-cerium composite catalytic electrode (approximately 100 cm²) was prepared. 2 ), Figure 19 The SEM images show that the prepared composite catalytic electrode has a smooth surface structure.

[0096] Performance testing

[0097] Test method: A two-chamber electrolytic cell was used. The cathode was the alumina-coated platinum-ruthenium-cerium composite catalytic electrode prepared in Example 5, the anode was a nickel mesh electrode, and the diaphragm was a composite diaphragm. The electrode working area of ​​the anode and cathode was 10 cm². 2 The test was conducted using a 6-compartment electrolytic cell. The average value of the cell voltages was taken as the electrolytic voltage. During the test, a peristaltic pump was used to introduce electrolyte into the electrolytic cell. A 30wt% KOH aqueous solution was introduced into the anode and cathode at a flow rate of 150 rpm / min, and the test temperature was 80℃. (1) The test current density was 200 mA / cm². 2 400mA / cm 2 600mA / cm 2 800mA / cm 2 1000mA / cm 2 (2) Test at 1000mA / cm 2 Stability under high current density for 500 hours was tested, and the surface deposition was observed using SEM after the test to compare the anti-deposition performance; (3) Test at 600 mA / cm 2 Anti-reverse polarity performance under current density was tested by electrolysis for 1 hour, shutdown for 1 hour, electrolysis for 1 hour, shutdown for 1 hour, repeating this process 200 times, and comparing the changes in electrolysis voltage.

[0098] Test results: When the cathode is an alumina-coated platinum-ruthenium-cerium composite catalytic electrode (Example 5), the current density is 200 mA / cm². 2 -1000mA / cm 2 The voltage for complete water decomposition is between 1.71V and 2.10V. Figure 20 ), and at 1000mA / cm 2 After operating at high current density for 500 hours, the total water splitting voltage can still be maintained at approximately 2.11V. Figure 21 As can be seen, the alumina-coated platinum-ruthenium-cerium composite catalytic electrode of the present invention exhibits high catalytic activity and long-term stability in water electrolysis, improving the service life of the composite catalytic electrode and reducing energy consumption. After electrolysis at high current density for 500 hours, only a small amount of particles were deposited on the surface of the alumina-coated platinum-ruthenium-cerium electrode in Example 5 (SEM image shown). Figure 22 This indicates that the composite catalytic electrode has strong anti-deposition ability. After 200 repeated electrolysis-shutdown tests, the electrolysis voltage maintenance rate in Example 5 was 95.6%, indicating that the composite catalytic electrode has strong anti-reverse polarity ability.

[0099] Example 6

[0100] A 46-mesh plain nickel mesh was selected as the substrate. An automatic sandblasting machine with No. 46 corundum and a power of 20kW was used to sandblast the nickel mesh for 45 minutes. The mesh was then ultrasonically treated for 1 hour to remove the corundum particles on the surface. Then, a 0.2 mol / L hydrochloric acid solution was prepared and used to etch the sandblasted nickel mesh for 1 hour to remove the highly reactive Ni particles on the surface. After washing with water and drying, a rough nickel mesh substrate was obtained.

[0101] A 0.05 mol / L chloroplatinic acid aqueous / ethanol solution was prepared, followed by the addition of ruthenium chloride and nickel chloride additives at a platinum:ruthenium:nickel molar ratio of 10:1:1. Hydrochloric acid stabilizer was also added, with a platinum:hydrochloric acid molar ratio of 5:1. The mixture was thoroughly mixed to obtain a platinum-ruthenium-nickel precursor solution. The platinum-ruthenium-nickel precursor was coated onto a nickel mesh surface using an automated spraying method. After drying in an oven at 80°C, it was calcined at 300°C for 2 hours in air. This spraying-drying-calcining process was repeated four times. Finally, it was solidified at 500°C for 3 hours and cooled to room temperature. The platinum-ruthenium-nickel loading was 0.15 mg / cm³. 2 .

[0102] A 0.02 mol / L cerium nitrate protective layer solution was prepared and then coated onto the surface of a platinum-ruthenium-nickel catalyst layer using an automated spraying method. The layer was then calcined at 500°C for 2 hours in air, and this process was repeated twice. The cerium oxide protective layer loading was 0.02 mg / cm³. 2 A cerium oxide-coated platinum-ruthenium-nickel composite catalytic electrode (approximately 3600 cm²) was prepared. 2 ), Figure 23 The electrode photographs show that the method of this invention can prepare large-area composite catalytic electrodes. Figure 24 The SEM images show that the prepared composite catalytic electrode has a smooth surface structure.

[0103] Performance testing

[0104] Test method: A two-chamber electrolytic cell was used. The cathode was the cerium oxide-coated platinum-ruthenium-nickel composite catalytic electrode prepared in Example 6, the anode was a nickel mesh electrode, and the diaphragm was a composite diaphragm. The electrode working area of ​​the anode and cathode was 10 cm². 2 The test was conducted using a 6-compartment electrolytic cell. The average value of the cell voltages was taken as the electrolytic voltage. During the test, a peristaltic pump was used to introduce electrolyte into the electrolytic cell. A 30wt% KOH aqueous solution was introduced into the anode and cathode at a flow rate of 150 rpm / min, and the test temperature was 80℃. (1) The test current density was 200 mA / cm². 2 400mA / cm 2 600mA / cm 2 800mA / cm 2 1000mA / cm 2 (2) Test at 1000mA / cm 2Stability under high current density for 500 hours was tested, and the surface deposition was observed using SEM after the test to compare the anti-deposition performance; (3) Test at 600 mA / cm 2 Anti-reverse polarity performance under current density was tested by electrolysis for 1 hour, shutdown for 1 hour, electrolysis for 1 hour, shutdown for 1 hour, repeating this process 200 times, and comparing the changes in electrolysis voltage.

[0105] Test results: When the cathode is a cerium oxide-coated platinum-ruthenium-nickel composite catalytic electrode (Example 6), the current density is 200 mA / cm². 2 -1000mA / cm 2 The voltage for complete water decomposition is between 1.64V and 2.05V. Figure 25 ), and at 1000mA / cm 2 After operating at high current density for 500 hours, the total water splitting voltage can still be maintained at approximately 2.06V. Figure 26 As can be seen, the cerium oxide-coated platinum-ruthenium-nickel composite catalytic electrode of the present invention exhibits high catalytic activity and long-term stability in water electrolysis, improving the service life of the composite catalytic electrode and reducing energy consumption. After electrolysis at high current density for 500 hours, only a small amount of particles were deposited on the surface of the cerium oxide-coated platinum-ruthenium-nickel electrode of Example 6 (SEM image shown). Figure 27 This indicates that the composite catalytic electrode has strong anti-deposition ability. After 200 repeated electrolysis-shutdown tests, the electrolysis voltage maintenance rate in Example 6 was 95.9%, indicating that the composite catalytic electrode has strong anti-reverse polarity ability.

[0106] Example 7

[0107] A 46-mesh plain nickel mesh was selected as the substrate. An automatic sandblasting machine with No. 46 corundum and a power of 15kW was used to sandblast the nickel mesh for 45 minutes. The mesh was then ultrasonically treated for 1 hour to remove the corundum particles on the surface. Then, a 0.2 mol / L hydrochloric acid solution was prepared and used to etch the sandblasted nickel mesh for 1 hour to remove the highly reactive Ni particles on the surface. After washing with water and drying, a rough nickel mesh substrate was obtained.

[0108] Prepare a 0.1 mol / L chloroplatinic acid aqueous / ethanol solution. Coat the platinum precursor onto the nickel mesh surface by brushing, dry in an oven at 100°C, and calcine at 300°C for 2 hours under a nitrogen atmosphere. Repeat the brushing-drying-calcination process three times. Finally, solidify at 500°C for 5 hours and cool to room temperature. The platinum loading is 0.6 mg / cm³. 2 .

[0109] A 0.02 mol / L cerium nitrate protective layer solution was prepared and then coated onto the surface of a platinum catalyst layer by brushing. The coating was then calcined at 450°C for 2 hours in air. This brushing-calcination process was repeated twice, resulting in a cerium oxide protective layer loading of 0.05 mg / cm³. 2 A cerium oxide-coated platinum composite catalytic electrode (approximately 100 cm²) was prepared.2 ).

[0110] Performance testing

[0111] Test method: A two-chamber electrolytic cell was used. The cathode was the cerium oxide-coated platinum composite catalytic electrode prepared in Example 7, the anode was a nickel mesh electrode, and the diaphragm was a composite diaphragm. The electrode working area of ​​the anode and cathode was 10 cm². 2 The test was conducted using a 6-compartment electrolytic cell. The average value of the cell voltages was taken as the electrolytic voltage. During the test, a peristaltic pump was used to introduce electrolyte into the electrolytic cell. A 30wt% KOH aqueous solution was introduced into the anode and cathode at a flow rate of 150 rpm / min, and the test temperature was 80℃. (1) The test current density was 200 mA / cm². 2 400mA / cm 2 600mA / cm 2 800mA / cm 2 1000mA / cm 2 (2) Test at 1000mA / cm 2 Stability under high current density for 500 hours was tested, and the surface deposition was observed using SEM after the test to compare the anti-deposition performance; (3) Test at 600 mA / cm 2 Anti-reverse polarity performance under current density was tested by electrolysis for 1 hour, shutdown for 1 hour, electrolysis for 1 hour, shutdown for 1 hour, repeating this process 200 times, and comparing the changes in electrolysis voltage.

[0112] Test results: When the cathode is a cerium oxide-coated platinum composite catalytic electrode (Example 7), the current density is 200 mA / cm². 2 -1000mA / cm 2 The total water decomposition voltage is between 1.63V and 2.10V, and is within 1000mA / cm. 2 After operating at high current density for 500 hours, the total water electrolysis voltage remained at approximately 2.15V. This demonstrates that the cerium oxide-coated platinum composite catalytic electrode of this invention exhibits high catalytic activity and long-term stability in water electrolysis, improving its lifespan and reducing energy consumption. After 500 hours of electrolysis at high current density, only a small amount of particles were deposited on the surface of the cerium oxide-coated platinum electrode in Example 7, indicating that the composite catalytic electrode has strong anti-deposition capabilities. After 200 repeated electrolysis-shutdown tests, the electrolysis voltage maintenance rate of the composite catalytic electrode in Example 7 was 94.3%, indicating that the composite catalytic electrode has strong anti-reverse polarity capabilities.

[0113] Example 8

[0114] A 46-mesh plain nickel mesh was selected as the substrate. An automatic sandblasting machine with No. 46 corundum and a power of 15kW was used to sandblast the nickel mesh for 45 minutes. The mesh was then ultrasonically treated for 1 hour to remove the corundum particles on the surface. Then, a 0.2 mol / L hydrochloric acid solution was prepared and used to etch the sandblasted nickel mesh for 1 hour to remove the highly reactive Ni particles on the surface. After washing with water and drying, a rough nickel mesh substrate was obtained.

[0115] A 0.1 mol / L ruthenium chloride ethanol / isopropanol solution was prepared, followed by the addition of nickel chloride additive (ruthenium to nickel molar ratio 10:1) and hydrochloric acid stabilizer (ruthenium to hydrochloric acid molar ratio 10:1). The mixture was thoroughly mixed to obtain a ruthenium-nickel precursor solution. The ruthenium-nickel precursor was coated onto a nickel mesh surface using an automated spraying method. After drying in an oven at 100°C, it was calcined at 300°C for 2 hours in air. This spraying-drying-calcination process was repeated three times. Finally, it was solidified at 500°C for 5 hours and cooled to room temperature. The ruthenium-nickel loading was 0.52 mg / cm³. 2 .

[0116] A 0.02 mol / L tetrabutyl titanate protective layer solution was prepared and then coated onto the surface of the ruthenium-nickel catalyst layer using an automated spraying method. The layer was then calcined at 450°C for 2 hours in air. This spraying-calcination cycle was repeated twice, resulting in a titanium dioxide protective layer loading of 0.04 mg / cm³. 2 A titanium oxide-coated ruthenium-nickel composite catalytic electrode (approximately 100 cm²) was prepared. 2 ).

[0117] Performance testing

[0118] Test method: A two-chamber electrolytic cell was used. The cathode was the titanium oxide-coated ruthenium-nickel composite catalytic electrode prepared in Example 8, the anode was a nickel mesh electrode, and the diaphragm was a composite diaphragm. The electrode working area of ​​the anode and cathode was 10 cm². 2 The test was conducted using a 6-compartment electrolytic cell. The average value of the cell voltages was taken as the electrolytic voltage. During the test, a peristaltic pump was used to introduce electrolyte into the electrolytic cell. A 30wt% KOH aqueous solution was introduced into the anode and cathode at a flow rate of 150 rpm / min, and the test temperature was 80℃. (1) The test current density was 200 mA / cm². 2 400mA / cm 2 600mA / cm 2 800mA / cm 2 1000mA / cm 2 (2) Test at 1000mA / cm 2 Stability under high current density for 500 hours was tested, and the surface deposition was observed using SEM after the test to compare the anti-deposition performance; (3) Test at 600 mA / cm 2Anti-reverse polarity performance under current density was tested by electrolysis for 1 hour, shutdown for 1 hour, electrolysis for 1 hour, shutdown for 1 hour, repeating this process 200 times, and comparing the changes in electrolysis voltage.

[0119] Test results: When the cathode is a titanium oxide-coated ruthenium-nickel composite catalytic electrode (Example 8), the current density is 200 mA / cm². 2 -1000mA / cm 2 The total water decomposition voltage is between 1.60V and 1.97V, and is within 1000mA / cm. 2 After operating at high current density for 500 hours, the total water electrolysis voltage remained at approximately 2.03V. This demonstrates that the titanium oxide-coated ruthenium-nickel composite catalytic electrode of this invention exhibits high catalytic activity and long-term stability in water electrolysis, improving the lifespan of the composite catalytic electrode and reducing energy consumption. After 500 hours of electrolysis at high current density, only a small amount of particles were deposited on the surface of the titanium oxide-coated ruthenium-nickel electrode in Example 8, indicating that the composite catalytic electrode has strong anti-deposition capabilities. After 200 repeated electrolysis-shutdown tests, the electrolysis voltage maintenance rate of the composite catalytic electrode in Example 8 was 75.3%, indicating that the ruthenium-based composite catalytic electrode has weaker anti-reverse polarity capabilities than the platinum-based composite catalytic electrode.

[0120] Example 9

[0121] A 46-mesh plain nickel mesh was selected as the substrate. An automatic sandblasting machine with No. 46 corundum and a power of 15kW was used to sandblast the nickel mesh for 45 minutes. The mesh was then ultrasonically treated for 1 hour to remove the corundum particles on the surface. Then, a 0.2 mol / L hydrochloric acid solution was prepared and used to etch the sandblasted nickel mesh for 1 hour to remove the highly reactive Ni particles on the surface. After washing with water and drying, a rough nickel mesh substrate was obtained.

[0122] A 0.1 mol / L palladium chloride solution in ethanol / isopropanol was prepared, followed by the addition of nickel chloride additive (palladium to nickel molar ratio 10:1) and hydrochloric acid stabilizer (palladium to hydrochloric acid molar ratio 10:1). The mixture was thoroughly mixed to obtain a palladium-nickel precursor solution. The palladium-nickel precursor was coated onto a nickel mesh surface using an automated spraying method. After drying in an oven at 100°C, it was calcined at 300°C for 2 hours in air. This spraying-drying-calcination process was repeated three times. Finally, it was solidified at 500°C for 5 hours and cooled to room temperature. The palladium-nickel loading was 0.54 mg / cm³. 2 .

[0123] A 0.02 mol / L tetrabutyl titanate protective layer solution was prepared and then coated onto the surface of the palladium-nickel catalyst layer using an automated spraying method. The coating was then calcined at 450°C for 2 hours in air. This spraying-calcination cycle was repeated twice, resulting in a titanium dioxide protective layer loading of 0.04 mg / cm³. 2 A titanium oxide-coated palladium-nickel composite catalytic electrode (approximately 100 cm²) was prepared. 2 ).

[0124] Performance testing

[0125] Test method: A two-chamber electrolytic cell was used. The cathode was the titanium oxide-coated palladium-nickel composite catalytic electrode prepared in Example 9, the anode was a nickel mesh electrode, and the diaphragm was a composite diaphragm. The electrode working area of ​​the anode and cathode was 10 cm². 2 The test was conducted using a 6-compartment electrolytic cell. The average value of the cell voltages was taken as the electrolytic voltage. During the test, a peristaltic pump was used to introduce electrolyte into the electrolytic cell. A 30wt% KOH aqueous solution was introduced into the anode and cathode at a flow rate of 150 rpm / min, and the test temperature was 80℃. (1) The test current density was 200 mA / cm². 2 400mA / cm 2 600mA / cm 2 800mA / cm 2 1000mA / cm 2 (2) Test at 1000mA / cm 2 Stability under high current density for 500 hours was tested, and the surface deposition was observed using SEM after the test to compare the anti-deposition performance; (3) Test at 600 mA / cm 2 Anti-reverse polarity performance under current density was tested by electrolysis for 1 hour, shutdown for 1 hour, electrolysis for 1 hour, shutdown for 1 hour, repeating this process 200 times, and comparing the changes in electrolysis voltage.

[0126] Test results: When the cathode is a titanium oxide-coated palladium-nickel composite catalytic electrode (Example 9), the current density is 200 mA / cm². 2 -1000mA / cm 2 The total water decomposition voltage is between 1.76V and 2.15V, and is within 1000mA / cm. 2 After operating at high current density for 500 hours, the total water electrolysis voltage remained at approximately 2.26V. This demonstrates that the titanium oxide-coated palladium-nickel composite catalytic electrode of this invention exhibits high catalytic activity and long-term stability in water electrolysis, improving the lifespan of the composite catalytic electrode and reducing energy consumption. After 500 hours of electrolysis at high current density, only a small amount of particles were deposited on the surface of the titanium oxide-coated palladium-nickel electrode in Example 9, indicating that the composite catalytic electrode has strong anti-deposition ability. After 200 repeated electrolysis-shutdown tests, the electrolysis voltage maintenance rate of the composite catalytic electrode in Example 9 was 81.5%, indicating that the palladium-based composite catalytic electrode has weaker anti-reverse polarity ability than the platinum-based composite catalytic electrode.

[0127] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A composite catalytic cathode for hydrogen evolution through water electrolysis, characterized in that, It includes a nickel matrix, a composite catalyst layer supported on the nickel matrix, and a protective layer covering the surface of the composite catalyst layer; The composite catalyst layer includes a noble metal catalyst, and the protective layer is a nanoporous metal oxide layer. The metal oxide is one or more of titanium oxide, cerium oxide, zirconium oxide, aluminum oxide, yttrium oxide, niobium oxide, tantalum oxide, and lanthanum oxide; the noble metal is one or more of platinum, ruthenium, and palladium.

2. The composite catalytic cathode for hydrogen evolution through water electrolysis according to claim 1, characterized in that, The composite catalyst layer also includes a catalytic aid.

3. The composite catalytic cathode for hydrogen evolution through water electrolysis according to claim 2, characterized in that, The total loading of the noble metal catalyst and the catalyst promoter is 0.01-20 mg / cm³. 2 The molar ratio of the noble metal catalyst to the catalytic promoter is 1:1-1000:1; the loading of the metal oxide is 0.01-0.2 mg / cm³. 2 .

4. The composite catalytic cathode for hydrogen evolution through water electrolysis according to claim 3, characterized in that, The total loading of the noble metal catalyst and the catalyst promoter is 0.05-1.0 mg / cm³. 2 The loading of the metal oxide is 0.02-0.05 mg / cm³. 2 .

5. The composite catalytic cathode for hydrogen evolution through water electrolysis according to claim 2, characterized in that, The catalyst is a metallic element, alloy, or oxide selected from one or more of Ni, Au, Ag, Zn, Ti, Ce, Mo, Co, Fe, Cu, and La.

6. The composite catalytic cathode for hydrogen evolution through water electrolysis according to claim 1, characterized in that, The nickel matrix is ​​nickel mesh, nickel alloy mesh, nickel foam, or nickel foam alloy.

7. A method for preparing a composite catalytic cathode for hydrogen evolution through water electrolysis according to any one of claims 1-6, characterized in that, include: A catalyst solution is formed by adding a stabilizer to a solution of a noble metal catalyst precursor compound, or by adding a catalyst promoter precursor compound and the stabilizer to the solution of the noble metal catalyst precursor compound; The catalyst solution is coated onto the surface of the nickel substrate and then sintered to form a composite catalyst layer; A metal oxide precursor solution is provided and coated onto the surface of the composite catalyst layer, followed by sintering to form the protective layer.

8. The preparation method according to claim 7, characterized in that, The stabilizer is one or more of hydrochloric acid, sulfuric acid, acetic acid, nitric acid, and citric acid.

9. The preparation method according to claim 7, characterized in that, The sintering steps for forming the composite catalyst layer include: sintering at 200-400℃ for 10 min-10 h in air, an inert atmosphere, or a reducing atmosphere, followed by calcination at 400-600℃ for 30 min-12 h; and / or The sintering step for forming the protective layer includes: calcining at 200-600°C for 5 min-12 h under air or inert atmosphere conditions.

10. The preparation method according to claim 9, characterized in that, The sintering steps for forming the composite catalyst layer include: sintering at 300-350°C for 10 min-2 h in air, an inert atmosphere, or a reducing atmosphere, followed by calcination at 450-550°C for 30 min-2 h; and / or The sintering step for forming the protective layer includes: calcining at 300-500°C for 30 min-2 h under air or inert atmosphere conditions.

11. The preparation method according to claim 7, characterized in that, The nickel substrate is roughened.

12. A water electrolysis and hydrogen evolution apparatus, characterized in that, The composite catalytic cathode for hydrogen evolution through water electrolysis, as described in any one of claims 1-6.

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