Hydrogen evolution electrode and preparation method and application thereof

Abstract

The invention relates to the technical field of hydrogen production, in particular to a hydrogen evolution electrode and a preparation method and application thereof. Specifically, the invention provides a hydrogen evolution electrode, the hydrogen evolution electrode comprises a conductive substrate, a protective layer and a catalyst layer, and the protective layer is located between the conductive substrate and the catalyst layer; wherein the conductive substrate is made of stainless steel, and the metal oxide is selected from one or more of metal oxides of zirconium, titanium, manganese, molybdenum and tungsten. By introducing the corrosion-resistant titanium oxide layer, a cheap stainless steel mesh can be adopted to replace a nickel wire mesh; meanwhile, in the hydrogen evolution electrode, compared with a single NiW catalyst and a commercial Raney nickel catalyst, the NiW / TiO2 composite catalyst adopted by the catalyst layer has a better hydrogen evolution catalytic effect.

Description

Technical Field

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

[0002] Hydrogen energy is an efficient, clean and environmentally friendly energy source. At present, the electrolysis of water is mature and widely used in the current commercial hydrogen production technology. Among them, alkaline water electrolysis is an important technology for realizing large-scale hydrogen production, and it is also one of the most mature hydrogen production technologies. In alkaline water electrolysis, the electrolyzer is its core component, which is composed of multiple unit chambers arranged in a regular pattern. Each chamber is mainly composed of plates, diaphragms, anode and cathode electrodes and pole frames. Hydrogen and oxygen are produced on the electrode surfaces of the cathode and anode, respectively. Among them, the catalyst plays a core and key role in the efficiency of the electrolyzer and directly affects the current density of the electrolyzer. At present, the cathode of the alkaline electrolyzer in industry mainly uses expensive nickel wire mesh as the support mesh and Raney nickel as the catalyst due to the strong alkaline environment. There is an urgent need to develop some catalysts with low cost and better catalytic performance for large-scale application in alkaline water electrolysis equipment. Summary of the invention

[0003] In view of the problems existing in the above-mentioned prior art, a cheap stainless steel mesh is used as a supporting mesh, on which a layer of titanium oxide with high chemical stability is coated to prevent the stainless steel mesh from being corroded, and at the same time a layer of Ni-W / TiO2 alloy oxide composite catalyst is deposited on it to promote the hydrogen evolution performance of the electrode.

[0004] A first aspect of the present invention provides a hydrogen evolution electrode, which includes a conductive substrate, a protective layer and a catalyst layer, wherein the protective layer is located between the conductive substrate and the catalyst layer; wherein the conductive substrate is stainless steel, and the metal oxide is selected from one or more metal oxides of zirconium, titanium, manganese, molybdenum and tungsten.

[0005] In one or more embodiments, the conductive substrate is in a mesh shape, and the mesh number is 30-80 meshes, such as 30-60 meshes, 30-50 meshes.

[0006] In one or more embodiments, the metal oxide is selected from one or more of zirconium dioxide, titanium dioxide, manganese dioxide, molybdenum trioxide, and tungsten trioxide.

[0007] In one or more embodiments, the metal oxide is in a particle form, and the particle size of the metal oxide is 1 to 20 nm.

[0008] In one or more embodiments, the particle size of the titanium metal oxide is 3 to 20 nm, preferably 5 to 15 nm.

[0009] In one or more embodiments, the particle size of the zirconium metal oxide is 3 to 15 nm, preferably 5 to 10 nm.

[0010] In one or more embodiments, the particle size of the molybdenum metal oxide is 1 to 15 nm, preferably 2 to 10 nm.

[0011] In one or more embodiments, the thickness of the protective layer is 0.1 to 5 μm, preferably 1 to 3 μm or 2 to 3 μm.

[0012] In one or more embodiments, the catalyst in the catalyst layer is selected from precious metal catalysts such as platinum-based and palladium-based catalysts, non-precious metal catalysts such as transition metal sulfides, phosphides, nitrides, carbides, and carbon-based non-metal catalysts such as carbon nanowires, carbon nanosheets, and carbon nanotubes.

[0013] In one or more embodiments, the catalyst in the catalyst layer is selected from a nickel-based alloy catalyst of one or more elements selected from aluminum, cobalt, chromium, molybdenum, tungsten, copper, titanium, boron, and zirconium, such as one or more of nickel-aluminum alloy (e.g., Raney nickel), nickel-tungsten alloy, nickel-molybdenum alloy, and nickel-cobalt alloy.

[0014] In one or more embodiments, the catalyst in the catalyst layer further contains a metal oxide, which is selected from one or more metal oxides of zirconium, titanium, manganese, molybdenum, and tungsten, and is the same as or different from the metal oxide in the protective layer.

[0015] In one or more embodiments, the content of the metal oxide in the catalyst layer is 1 to 5 wt %.

[0016] A second aspect of the present invention provides a method for preparing a hydrogen evolution electrode as described in any embodiment herein, the method comprising modifying a conductive substrate with a metal oxide, and then coating a catalyst layer on the surface of the conductive substrate to obtain a hydrogen evolution electrode.

[0017] In one or more embodiments, the step of modifying the conductive substrate comprises drying and calcining the conductive substrate coated with the metal oxide sol.

[0018] In one or more embodiments, the metal oxide sol is prepared from a precursor, a low-carbon alcohol, a peptizing agent, and a chelating agent.

[0019] In one or more embodiments, the precursor is an ester or salt of the metal oxide corresponding to the metal.

[0020] In one or more embodiments, when the metal oxide is titanium oxide, the precursor is selected from one or more of titanyl sulfate, titanium sulfate, tetraethyl titanate, tetrabutyl titanate, titanium tetrachloride, titanium tetrafluoride, titanium n-propoxide, and titanium trichloride, more preferably tetrabutyl titanate.

[0021] In one or more embodiments, when the metal oxide is zirconium oxide, the precursor is selected from one or more of zirconium tetrachloride, zirconium acetate, and zirconium oxychloride, more preferably zirconium oxychloride 8-hydrate.

[0022] In one or more embodiments, when the metal oxide is molybdenum oxide, the precursor is selected from one or more of ammonium molybdate, molybdenum nitrate, molybdic acid, molybdenum isopropoxide, and molybdenum oxide, more preferably molybdenum nitrate.

[0023] In one or more embodiments, the low-carbon alcohol is selected from one or more of methanol, ethanol, isopropanol, n-propanol, and n-butanol, preferably n-butanol.

[0024] In one or more embodiments, the peptizing agent is an inorganic acid and / or an organic acid, the inorganic acid is selected from one or more of nitric acid, phosphoric acid, hydrochloric acid, and sulfuric acid, and the organic acid is selected from one or more of oxalic acid, acetic acid (acetic acid or glacial acetic acid), and citric acid.

[0025] In one or more embodiments, the chelating agent is selected from one or more of α-methacrylic acid, acrylic acid, acetylacetone and benzoylacetone, more preferably acetylacetone.

[0026] In one or more embodiments, the molar ratio of the precursor, solvent, peptizing agent and chelating agent is (0.5-1.5):(100-150):(1.5-2.5):(0.1-1).

[0027] In one or more embodiments, the molar ratio of the precursor, solvent, peptizing agent and chelating agent is (0.8-1.2):(110-130):(1.8-2.2):(0.5-0.7).

[0028] In one or more embodiments, the drying condition is 30-80° C. for 3-10 h, preferably 50-70° C. for 5-7 h.

[0029] In one or more embodiments, the calcination conditions are 300-800° C. for 2-6 h, preferably 400-500° C. for 3-5 h.

[0030] In one or more embodiments, the catalyst layer is deposited onto the metal oxide modified conductive substrate surface by electrodeposition.

[0031] In one or more embodiments, the electroplating solution for electrodeposition includes a nickel salt, a non-nickel metal salt, a complex, and an optional anode stabilizer, and the non-nickel metal is as described in any embodiment herein.

[0032] In one or more embodiments, the complex includes organic acids and / or organic acid salts, such as citrate and / or citric acid.

[0033] In one or more embodiments, the anode stabilizer includes an enamine compound.

[0034] In one or more embodiments, in the electroplating solution of the electrodeposition, the concentration of the nickel salt can be 50-80 g / L, preferably 60-70 g / L, the concentration of the tungstate can be 70-100 g / L, preferably 80-90 g / L, and the concentration of the complex can be 70-100 g / L, preferably 80-90 g / L.

[0035] In one or more embodiments, the electroplating solution for electrodeposition further includes a metal oxide, which is the same as or different from the metal oxide used to modify the conductive substrate.

[0036] In one or more embodiments, the electrodeposition conditions are 40-100°C, 1-5 Adm -2 Deposition for 30 to 60 minutes, preferably at 50 to 80°C, 2 to 4 Adm -2 The sedimentation was continued for 40 to 60 minutes.

[0037] The third aspect of the present invention provides an application of a hydrogen evolution electrode as described in any embodiment herein in improving the hydrogen evolution catalytic efficiency of an alkaline water electrolysis hydrogen production electrolyzer, or in preparing an alkaline water electrolysis hydrogen production electrolyzer with improved hydrogen evolution catalytic efficiency, wherein the alkaline water electrolysis hydrogen production electrolyzer comprises the hydrogen evolution electrode.

[0038] The third aspect of the present invention also provides a method for improving the hydrogen evolution catalytic efficiency of an alkaline water electrolysis hydrogen production electrolyzer, the method comprising the step of applying the hydrogen evolution electrode as described in any embodiment of the present invention to the alkaline water electrolysis hydrogen production electrolyzer.

[0039] A fourth aspect of the present invention provides the use of a hydrogen evolution electrode as described in any embodiment herein in the production of hydrogen by alkaline water electrolysis, or the use of the hydrogen evolution electrode in the preparation of an electrolytic cell for producing hydrogen by alkaline water electrolysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 LSV linear voltammetric curves of hydrogen evolution on different catalysts. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0042] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0043] Herein, “comprising”, “including”, “containing” and similar terms encompass the meanings of “consisting essentially of” and “consisting of”. For example, when “A comprises B and C” is disclosed herein, “A consists essentially of B and C” and “A consists of B and C” should be deemed to be disclosed herein.

[0044] In this article, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are only for brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0045] In this document, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0046] Herein, the sum of the percentages of the various components of the composition is 100%.

[0047] Herein, when describing embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all substitutes, improvements and equivalents of the methods and materials described in the present invention can be included in the scope limited by the claims.

[0048] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0049] The present invention finds that using a stainless steel mesh substrate modified with oxide and coated with a nickel-tungsten alloy composite titanium dioxide catalyst as a hydrogen evolution electrode to replace a conventional nickel-based hydrogen evolution electrode has a good technical effect.

[0050] Hydrogen Evolution Electrode

[0051] The present invention first provides a hydrogen evolution electrode, which includes an oxide-modified conductive substrate and a catalyst layer coated on the surface thereof. The catalyst layer includes a nickel-tungsten alloy composite catalyst. In the oxide layer, the oxide can be one or more oxides of metals such as zirconium, titanium, manganese, molybdenum, tungsten, etc., for example, one or more of zirconium dioxide, titanium dioxide, manganese dioxide, molybdenum trioxide, and tungsten trioxide. The catalyst layer can also include a metal oxide, which can be the same as or different from the metal oxide used for modification.

[0052] In the hydrogen evolution electrode of the present invention, the conductive substrate can be a material with good conductive properties commonly used in the art, such as a metal or an alloy. In the present invention, stainless steel is used as the conductive substrate support mesh. There is no special restriction on the material of the stainless steel, and the commonly used 304, 316, and 430 stainless steels on the market can achieve good results. It should be understood that the higher the mesh number of the conductive substrate support mesh, the higher the specific surface area of ​​the hydrogen evolution electrode for catalytic reaction in the electrolyzer, and the better the effect. Therefore, in some embodiments, the mesh number of the conductive substrate support mesh of the present invention can be 30 to 80 meshes, for example, 30 to 60 meshes, 30 to 50 meshes.

[0053] In the hydrogen evolution electrode of the present invention, the surface of the conductive substrate has a modified layer (protective layer) modified by an oxide. In some embodiments, the oxide is one or more of titanium oxide, molybdenum oxide, and zirconium oxide. The oxide can be in the form of particles. It should be understood that the smaller the size of the oxide particles in the protective layer, the denser the protective layer, and the more helpful it is to improve the corrosion resistance of the support network. Its size can be 1 to 20 nm, which is selected according to the actual material of each oxide and the required thickness of the protective layer. For example, the size of titanium oxide particles can be 3 to 20 nm, preferably 5 to 15 nm, the size of zirconium oxide particles can be 3 to 15 nm, preferably 5 to 10 nm, and the size of molybdenum oxide particles can be 1 to 15 nm, preferably 2 to 10 nm; the thickness of the protective layer can be 0.1 to 5 μm, preferably 1 to 3 μm or 2 to 3 μm, which is selected according to the needs of the electrode reaction and the needs of corrosion resistance.

[0054] In the hydrogen evolution electrode of the present invention, the surface of the oxide-modified conductive substrate is coated with a catalyst layer. The catalyst may be a catalyst commonly used in the art, including but not limited to precious metal catalysts such as platinum-based and palladium-based catalysts, non-precious metal catalysts such as transition metal sulfides, phosphides, nitrides, and carbides, carbon-based non-metal-based catalysts such as carbon nanowires, carbon nanosheets, and carbon nanotubes, such as Raney nickel, activated nickel-aluminum alloys, activated nickel-molybdenum alloys, nickel sulfide, etc. In the present invention, the thickness of the catalyst layer may be 1 to 20 μm, for example, 1 to 10 μm.

[0055] In some embodiments, the catalyst layer of the present invention may also contain metal oxide particles, which may be the same as or different from the metal oxide in the modification layer (protective layer). The mass of the metal oxide is 1 to 5 wt % of the total mass of the catalyst layer. The concentration of the metal oxide particles may be adjusted according to actual needs, for example, in the metal oxide solution, the concentration of the metal oxide particles is 0.5 to 1.5 g / L or 1 to 2 g / L.

[0056] Preparation method

[0057] The present invention also provides a method for preparing a hydrogen evolution electrode as described in any embodiment of the present invention, the method comprising modifying a conductive substrate with a metal oxide, coating a catalyst layer on the conductive substrate, and obtaining the hydrogen evolution electrode.

[0058] In the step of modifying the conductive substrate, a metal oxide sol can be first prepared by a sol-gel method, and the conductive substrate coated with the metal oxide sol is dried and calcined to obtain a conductive substrate modified with a metal oxide. Specifically, a metal oxide source can be used as a precursor, mixed with a low-carbon alcohol, and a peptizing agent and a chelating agent are added to obtain a metal oxide sol. In some embodiments, modifying the conductive substrate with a metal oxide refers to coating the metal oxide sol on the surface of the conductive substrate.

[0059] In the metal oxide sol, the metal oxide source is an ester, salt, etc. of the corresponding metal, for example, the metal oxide is titanium oxide, and the metal oxide source is a titanium source (ester, salt containing titanium), including but not limited to titanyl sulfate, titanium sulfate, tetraethyl titanate, tetrabutyl titanate, titanium tetrachloride, titanium tetrafluoride, n-propoxide titanium, titanium trichloride, one or more, more preferably tetrabutyl titanate; for example, the metal oxide is zirconium oxide, and the precursor includes but is not limited to zirconium tetrachloride, zirconium acetate, zirconium oxychloride, etc.; for example, the metal oxide is molybdenum oxide, and the precursor includes but is not limited to ammonium molybdate, molybdenum nitrate, molybdic acid, isopropoxide of molybdenum, one or more of molybdenum oxide, more preferably molybdenum nitrate. Low-carbon alcohol is liquid at room temperature, such as one or more of methanol, ethanol, isopropanol, n-propanol, and n-butanol, preferably n-butanol. In the metal oxide sol, the peptizing agent can be an inorganic acid and / or an organic acid, and the inorganic acid can be one or more of nitric acid, phosphoric acid, hydrochloric acid, and sulfuric acid, and the organic acid can be one or more of oxalic acid, acetic acid (acetic acid or glacial acetic acid), and citric acid. In the metal oxide sol, the chelating agent can be a chelating agent commonly used in the art, including but not limited to one or more of α-methylacrylic acid, acrylic acid, acetylacetone and phenylacetone. In the metal oxide sol, the ratio of the precursor, low-carbon alcohol, peptizing agent and chelating agent can be adjusted according to actual conditions. In an exemplary embodiment, the molar ratio of the precursor, solvent, peptizing agent and chelating agent is (0.5-1.5): (100-150): (1.5-2.5): (0.1-1), more preferably (0.8-1.2): (110-130): (1.8-2.2): (0.5-0.7). The metal oxide sol is coated on a conductive substrate, and the coating thickness, drying time and temperature, calcination time and temperature can be adjusted according to actual needs. For example, drying at 30-80°C for 3-10 hours, preferably drying at 50-70°C for 5-7 hours; calcining at 300-800°C for 2-6 hours, preferably calcining at 400-500°C for 3-5 hours. In the present invention, oxides are used to modify the conductive substrate to protect the conductive substrate and resist corrosion.

[0060] In the step of coating the catalyst layer, the nickel-tungsten alloy and the optional metal oxide composite catalyst can be deposited onto the conductive substrate modified by the metal oxide by electrodeposition to obtain the hydrogen evolution electrode of the present invention. Before electrodeposition, a nickel-tungsten alloy electroplating solution can be prepared first. The nickel-tungsten alloy electroplating solution can include nickel salts, tungstates, complexes and optional anode stabilizers, etc. The complexes can be organic acids and / or organic acid salts, such as citrates and / or citric acid, and the anode stabilizers can be enamine compounds. Electrodeposited nickel-tungsten alloy has excellent corrosion resistance and wear resistance and a long service life. In the electroplating solution, the concentration of the nickel salt can be 50-80 g / L, preferably 60-70 g / L, the concentration of the tungstate can be 70-100 g / L, preferably 80-90 g / L, and the concentration of the complex can be 70-100 g / L, preferably 80-90 g / L. The electroplating solution of the present invention may also contain metal oxides. The metal oxide particles may be the same as or different from the metal oxide in the protective layer. The metal oxide is in the form of particles and may have a size of 3 to 30 nm, such as 5 to 15 nm. After obtaining the electroplating solution, the temperature, current and time of the electrodeposition may be adjusted according to actual needs, such as 40 to 100°C, 1 to 5 Adm -2 Deposition for 30 to 60 minutes, preferably at 50 to 80°C, 2 to 4 Adm -2 The sedimentation was continued for 40 to 60 minutes.

[0061] application

[0062] Based on the above findings, the hydrogen evolution electrode of the present invention can improve the hydrogen evolution catalytic effect of the electrolyzer. Therefore, the present invention also provides the use of the hydrogen evolution electrode as described in any embodiment of the present invention in improving the hydrogen evolution catalytic efficiency of the alkaline water electrolysis hydrogen production electrolyzer, or in preparing the alkaline water electrolysis hydrogen production electrolyzer with improved hydrogen evolution catalytic efficiency, and the alkaline water electrolysis hydrogen production electrolyzer includes the hydrogen evolution electrode.

[0063] In the process of hydrogen production by alkaline water electrolysis, there is a certain relationship between the efficiency of the electrolyzer and the current density. Generally speaking, a lower current density can improve the efficiency of the electrolyzer. However, the current of the industrial alkaline water electrolysis hydrogen production electrolyzer is generally around 2000-4000A. Too low a current density may cause the efficiency of the hydrogen evolution electrode to be too slow.

[0064] In some embodiments, the present invention also provides a method for improving the hydrogen evolution catalytic efficiency of an alkaline water electrolysis hydrogen production electrolyzer, the method comprising the step of applying the hydrogen evolution electrode as described in any embodiment herein to the alkaline water electrolysis hydrogen production electrolyzer.

[0065] Electrolyzer / Electrolysis Water Reaction System

[0066] The electrolysis reaction system includes a cathode, an anode and an electrolyte, and the reaction usually occurs in an electrolyzer. The electrolyzer is regularly arranged by a plurality of unit cells, each of which includes a bipolar plate, a cathode electrode, an anode electrode, a diaphragm (diaphragm) and a pole frame. Therefore, the present invention also provides the use of a hydrogen-precipitating electrode in alkaline water electrolysis hydrogen production as described in any embodiment herein, or the use of the hydrogen-precipitating electrode in an electrolyzer for preparing alkaline water electrolysis hydrogen production. In some embodiments, the present invention also provides a method for preparing an electrolyzer, the method comprising the steps of a method for preparing a hydrogen-precipitating electrode as described in any embodiment herein.

[0067] The two ends of the electrolytic cell are respectively equipped with an anode and a cathode, and the cell is filled with electrolyte. The pole frame is arranged outside the bipolar plate, and the bipolar plate and the pole frame can be integrated, collectively referred to as the pole plate.

[0068] The electrode includes a current collector and a catalyst coated on the surface of the current collector, which is divided into a cathode electrode (hydrogen evolution electrode) and an anode electrode (oxygen evolution electrode). Usually, the oxygen evolution electrode is a pure nickel mesh or nickel foam, or a composite catalytic functional layer on the surface of the first two, such as a nickel-based self-supporting electrode with one or more catalyst layers of single metal, bimetallic and multi-metal, non-metallic element doping. Among them, the monometallic catalyst includes but is not limited to nickel hydroxide / nickel oxide electrodes, the bimetallic catalyst layer includes but is not limited to nickel iron, nickel cobalt, and nickel copper catalysts with LDH structure, and the catalyst layer doped with non-metallic elements includes but is not limited to the introduction of non-metallic elements such as phosphorus, sulfur, nitrogen, etc. in the nickel-based catalyst layer. Under alkaline conditions, the nickel-based catalyst layer mainly exists in the form of oxides or hydroxides. In an exemplary embodiment, in the electrolytic cell of the present invention, the anode is a nickel wire mesh electrode.

[0069] In the alkaline water electrolysis hydrogen production electrolyzer of the present invention, the electrolyte is an alkaline electrolyte commonly used in the art, such as potassium hydroxide solution or sodium hydroxide solution. In an exemplary embodiment, in the electrolyzer of the present invention, the electrolyte is a potassium hydroxide solution with a concentration of 10-30%.

[0070] The present invention has the following beneficial effects:

[0071] The present invention introduces a corrosion-resistant titanium oxide layer, so that a cheap stainless steel mesh can be used to replace the nickel wire mesh; at the same time, in the hydrogen evolution electrode of the present invention, the catalytic layer adopts a NiW / TiO2 alloy oxide composite catalyst, which has a better hydrogen evolution catalytic effect than a single NiW alloy catalyst and a commercial Raney nickel catalyst.

[0072] The present invention will be further described in the following by way of specific examples. It should be understood that these examples are merely illustrative and are not intended to limit the scope of the present invention. The methods and reagents used in the examples are conventional methods and reagents in the art unless otherwise specified. In the homemade 1 cubic electrolytic cell of the present invention, the anode is a 45-mesh nickel wire mesh electrode, and the electrolyte is a 10-30% potassium hydroxide solution; when the detection environment of the electrolytic cell is 85°C, the electrolyte is a 30% potassium hydroxide solution and the voltage is 2V. The particle size of the oxide particles is obtained by electron microscopy and XRD.

[0073] Example 1: Study on the role of the modification layer

[0074] like Figure 1 As shown in Table 1, the hydrogen evolution performance of the hydrogen evolution electrode coated with NiW / TiO2 catalyst layer is further improved compared with the hydrogen evolution electrode with NiW / TiO2 catalyst layer; and the hydrogen evolution performance of the stainless steel support mesh coated with NiW / TiO2 catalyst layer and modified with TiO2 is the best. In addition, it can be seen from hydrogen evolution electrodes 3 and 4 that when the catalyst layer is NiW / TiO2, the modified layer (protective layer) modified with TiO2 only plays a role in corrosion protection for the conductive substrate, and has no obvious negative impact on the electrocatalytic effect.

[0075] Table 1: Electrode composition

[0076]

[0077] Note: “×” means not contained.

[0078] Example 2: Study on the role of different material modification layers and catalyst layers

[0079] Example 1

[0080] Preparation of titanium oxide layer: Use 45 mesh stainless steel mesh 316L as the support mesh, clean and dry it for use, use tetrabutyl titanate as the precursor, n-butanol as the solvent, nitric acid, acetylacetone as the chelating agent, and the molar ratio of sol precursor, solvent, acid, and chelating agent is 1:120:2:0.5 to obtain titanium sol. After drying the stainless steel mesh coated with titanium sol at 60°C for 6h, calcined at 450°C for 4h to obtain a titanium oxide modified support mesh. The titanium oxide particle size of the obtained titanium oxide layer is about 5-15nm and the thickness is 2μm.

[0081] Electrode preparation: The support mesh prepared above is cleaned and dried for later use.

[0082] Electroplating solution configuration: nickel sulfate concentration is 60g / L, sodium tungstate concentration is 80g / L, citric acid concentration is 80g / L, titanium oxide particle concentration is 1g / L. -2Under current, the hydrogen evolution electrode was deposited under the above support mesh for 60 minutes, and its thickness was found to be about 10 μm through electron microscopy observation.

[0083] Comparative Example 1

[0084] Electroplating solution configuration: nickel sulfate concentration is 60g / L, sodium tungstate concentration is 80g / L, citric acid concentration is 80g / L, titanium oxide particle concentration is 1g / L. At 60℃, 2Adm -2 Under current, the electrode was deposited on a 45-mesh stainless steel mesh 316L for 60 minutes to obtain a hydrogen evolution electrode, and its thickness was found to be about 10 μm through electron microscopy observation.

[0085] Comparative Example 2

[0086] Preparation of titanium oxide layer: 45 mesh stainless steel mesh 316L is used as the support mesh, which is cleaned and dried for standby use. Tetrabutyl titanate is used as the precursor, n-butanol is used as the solvent, nitric acid and acetylacetone are used as the chelating agent, and the molar ratio of the sol precursor, solvent, acid and chelating agent is 1:120:2:0.5. The stainless steel mesh coated with titanium sol is dried at 60°C for 6 hours and calcined at 450°C for 4 hours to obtain a titanium oxide modified support mesh. The titanium oxide particle size of the obtained titanium oxide layer is about 5 to 15 nm and the thickness is 2 μm.

[0087] Electrode preparation: The support mesh prepared above is cleaned and dried to obtain a hydrogen evolution electrode.

[0088] Example 2

[0089] Preparation of zirconium oxide layer: 60 mesh stainless steel mesh 304L is used as the support mesh, which is washed and dried for standby use. 8-water zirconium oxychloride is used as the precursor, water is used as the solvent, nitric acid and acetylacetone are used as the chelating agent, and the molar ratio of the sol precursor, solvent, acid and chelating agent is 1:130:4:0.5. After drying the stainless steel mesh coated with zirconium sol, it is calcined at 500°C for 3h to obtain a zirconium oxide modified support mesh. The zirconium oxide particle size of the obtained zirconium oxide layer is about 5-10nm and the thickness is 1μm.

[0090] Electrode preparation: The support mesh prepared above is cleaned and dried for later use.

[0091] Plating solution configuration: nickel sulfate concentration is 80g / L, sodium tungstate concentration is 80g / L, citric acid concentration is 100g / L, zirconium oxide particle concentration is 0.5g / L. -2 Under current, the electrode was deposited under the above support mesh for 50 minutes to obtain a hydrogen evolution electrode, and its thickness was found to be about 8 μm through electron microscopy observation.

[0092] Example 3

[0093] Preparation of molybdenum oxide layer: Use 50 mesh stainless steel mesh 304L as the support mesh, clean and dry it for use, use molybdenum nitrate as the precursor, water as the solvent, nitric acid, acetylacetone as the chelating agent, and the molar ratio of sol precursor, solvent, acid, and chelating agent is 1:150:4:0.5. After drying the stainless steel mesh coated with molybdenum sol, calcined at 400℃ for 4h to obtain a titanium oxide modified support mesh. The molybdenum oxide particle size of the obtained molybdenum oxide layer is about 2 to 10nm and the thickness is 3μm.

[0094] Electrode preparation: The support mesh prepared above is cleaned and dried for later use.

[0095] Plating solution configuration: nickel sulfate concentration is 100g / L, sodium tungstate concentration is 80g / L, citric acid concentration is 120g / L, molybdenum oxide particle concentration is 0.1g / L. -2 Under current, the electrode was deposited under the above support mesh for 30 minutes to obtain a hydrogen evolution electrode, and its thickness was found to be about 6 μm through electron microscopy observation.

[0096] The above hydrogen evolution electrodes were placed in a self-made 1 cubic electrolytic cell, the alkali solution was 30% KOH, and the single cell was operated at 2V voltage for 2000h. The current of each hydrogen evolution electrode was detected: the current of the hydrogen evolution electrode obtained in Example 1-3 was stable at 4000A / m 2 ; After running for 2000h in Comparative Example 1, the electrolytic cell was disassembled and found to be severely corroded by the electrodes and the support network; the current of Comparative Example 2 was stable at 3000A / m 2 .

[0097] In summary, the results show that the coating of the protective layer improves the electrical corrosion resistance of the stainless steel support mesh, and that, at the same voltage, the electrocatalytic effect of the nickel-tungsten alloy / oxide composite catalyst layer is better than that of the commercial Raney nickel catalyst, and the current density of the electrolytic cell containing the latter is lower.

Claims

1. A hydrogen evolution electrode, comprising a conductive substrate, a protective layer and a catalyst layer, wherein the protective layer is located between the conductive substrate and the catalyst layer, characterized in that: The conductive substrate is stainless steel, and the protective layer is composed of one or more metal oxides selected from zirconium, titanium, manganese, molybdenum and tungsten.

2. The hydrogen evolution electrode according to claim 1, characterized in that The conductive substrate is in a mesh shape, and the mesh number of the conductive substrate is 30 to 80 meshes, preferably 30 to 60 meshes.

3. The hydrogen evolution electrode according to claim 1, characterized in that The metal oxide is selected from one or more of zirconium dioxide, titanium dioxide, manganese dioxide, molybdenum trioxide and tungsten trioxide.

4. The hydrogen evolution electrode according to claim 3, characterized in that The metal oxide is in granular form, and the particle size of the metal oxide is 1 to 20 nm; Preferably, The metal oxide is titanium dioxide, and its particle size is 3 to 20 nm, preferably 5 to 15 nm; The metal oxide is zirconium dioxide, and its particle size is 3 to 15 nm, preferably 5 to 10 nm; The metal oxide is molybdenum trioxide, and the particle size thereof is 1 to 15 nm, preferably 2 to 10 nm.

5. The hydrogen evolution electrode according to claim 1, characterized in that The catalyst in the catalyst layer is selected from precious metal catalysts such as platinum-based and palladium-based catalysts, non-precious metal catalysts such as transition metal sulfides, phosphides, nitrides, carbides, and carbon-based non-metal catalysts such as carbon nanowires, carbon nanosheets, and carbon nanotubes.

6. The hydrogen evolution electrode according to claim 5, characterized in that The catalyst in the catalyst layer is a nickel-based alloy catalyst of one or more elements selected from aluminum, cobalt, chromium, molybdenum, tungsten, copper, titanium, boron and zirconium.

7. The hydrogen evolution electrode according to claim 1, characterized in that The catalyst layer further contains one or more metal oxides selected from zirconium, titanium, manganese, molybdenum and tungsten, and the metal oxide in the catalyst layer is the same as or different from the metal oxide in the protective layer; Preferably, the content of the metal oxide in the catalyst layer is 1 to 5 wt %.

8. A method for preparing a hydrogen evolution electrode as claimed in any one of claims 1 to 7, characterized in that: The method comprises modifying a conductive substrate with the metal oxide, and then coating the surface of the conductive substrate with a catalyst layer to obtain a hydrogen evolution electrode; Preferably, the step of modifying the conductive substrate comprises drying and calcining the conductive substrate coated with the metal oxide sol; Preferably, the metal oxide sol is prepared from a precursor, a low-carbon alcohol, a peptizing agent and a chelating agent; Preferably, the catalyst layer is deposited onto the surface of the metal oxide-modified conductive substrate by electrodeposition.

9. The method according to claim 8, characterized in that The method has one or more of the following characteristics: The precursor is an ester or salt of the metal corresponding to the metal oxide; When the metal oxide is titanium oxide, the precursor is selected from one or more of titanyl sulfate, titanium sulfate, tetraethyl titanate, tetrabutyl titanate, titanium tetrachloride, titanium tetrafluoride, titanium n-propoxide, and titanium trichloride, and is more preferably tetrabutyl titanate; When the metal oxide is zirconium oxide, the precursor is selected from one or more of zirconium tetrachloride, zirconium acetate, and zirconium oxychloride, and more preferably zirconium oxychloride 8-hydrate; When the metal oxide is a molybdenum oxide, the precursor is selected from one or more of ammonium molybdate, molybdenum nitrate, molybdic acid, molybdenum isopropoxide, and molybdenum oxide, more preferably molybdenum nitrate; The low-carbon alcohol is selected from one or more of methanol, ethanol, isopropanol, n-propanol, and n-butanol, preferably n-butanol; The peptizing agent is an inorganic acid and / or an organic acid, the inorganic acid is selected from one or more of nitric acid, phosphoric acid, hydrochloric acid, and sulfuric acid, and the organic acid is selected from one or more of oxalic acid, acetic acid, and citric acid; The chelating agent is selected from one or more of α-methacrylic acid, acrylic acid, acetylacetone and benzoyl acetone, more preferably acetylacetone; The molar ratio of the precursor, the solvent, the peptizing agent and the chelating agent is (0.5-1.5):(100-150):(1.5-2.5):(0.1-1).

10. An application of the hydrogen evolution electrode according to any one of claims 1 to 7 in improving the hydrogen evolution catalytic efficiency of an alkaline water electrolysis hydrogen production electrolyzer, or in preparing an alkaline water electrolysis hydrogen production electrolyzer with improved hydrogen evolution catalytic efficiency, wherein the alkaline water electrolysis hydrogen production electrolyzer comprises the hydrogen evolution electrode.

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