A method for preparing a nickel alloy-metal oxide composite hydrogen evolution electrode

Abstract

The present application relates to hydrogen energy field, provide a kind of preparation method of nickel alloy-metal oxide composite hydrogen evolution electrode.The present application includes the following steps: the oil dirt and surface oxide of nickel substrate are removed by pretreatment, configure mixed solution with nickel salt and metal oxide nanoparticles as main component, and carry out ultrasonic dispersion uniformly;Then with nickel substrate as working electrode, electrochemical deposition is carried out in mixed solution;After depositing for a certain time of intermediate layer, add solution containing molybdenum or molybdenum tungsten in deposition solution, stir uniformly, then carry out two-stage electrodeposition;After deposition, the electrode is taken out and dried, to obtain the composite electrode of nickel molybdenum or nickel molybdenum tungsten and metal oxide.The hydrogen evolution electrocatalytic activity of the prepared composite electrode is high, and the stability is good, which helps to improve the hydrogen production rate of alkaline electrolysis hydrogen production equipment and reduce the cost of hydrogen production.The preparation method of the composite electrode is simple, without high temperature and high pressure process, low cost, suitable for large-scale industrial production.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of hydrogen energy, and in particular to a preparation method of a nickel alloy-metal oxide composite hydrogen evolution electrode. BACKGROUND

[0002] With the continuous decline of wind and light power costs, the preparation of green hydrogen by renewable power electrolysis will gradually develop into the main way of green hydrogen production, and the preparation of hydrogen by renewable power electrolysis is also an important way to achieve the double carbon goal.

[0003] Alkaline water electrolysis is the main way of current commercialized hydrogen production by electrolysis, and in the future, hydrogen production by hydroxyl ion exchange membrane electrolysis of water also has excellent development prospects. Both of these two methods of hydrogen production by electrolysis can use non-noble metal catalysts, and have the significant advantage of low electrode cost. In an alkaline system, a nickel-based material is generally used for a hydrogen evolution electrode, such as twill nickel mesh, stretched rhombic nickel mesh, foamed nickel mesh, or nickel-aluminum, nickel-molybdenum, nickel-cobalt alloy, etc.

[0004] In order to reduce the hydrogen evolution voltage of alkaline water electrolysis, researchers load a catalytic layer on a nickel substrate to improve the hydrogen evolution current density and reduce the overpotential. Chinese patent CN201910402757.6 discloses a preparation method of an alloy hydrogen evolution electrode loaded on a foamed transition metal, first, a three-dimensional foamed transition metal substrate electrode is subjected to oil removal and acid pickling pretreatment, then the treated porous foamed transition metal is placed into a glow plasma metal infiltration furnace as a substrate, a molybdenum plate with a purity of 99.99% is used as a sputtering target, and a molybdenum-molybdenum transition metal alloy hydrogen evolution electrode is generated on the surface of the foamed transition metal. However, this method requires expensive equipment, and the hydrogen evolution activity and stability of the prepared electrode still need to be improved. Chinese patent CN202211064473.9 discloses a preparation method of a nickel-molybdenum-tungsten loaded porous nickel-based self-supporting catalytic hydrogen evolution cathode material, in which a porous nickel (NF) is used as a substrate, an electrochemical deposition method is used to modify the substrate with a nickel-molybdenum-tungsten ternary alloy coating layer, and the substrate is subjected to heat treatment to obtain a final NiMoW@NF hydrogen evolution electrode. However, the alloy electrode obtained by direct electrodeposition has insufficient stability due to the stress of the coating layer or the nature of Mo element that is easily dissolved in an alkaline condition.

[0005] In summary, the current alkaline water nickel-based hydrogen evolution electrode has the problems of high preparation cost or insufficient hydrogen evolution activity and stability of the prepared electrode. SUMMARY

[0006] Therefore, the application provides a preparation method of a nickel alloy-metal oxide composite hydrogen evolution electrode. The application adopts the following specific schemes:

[0007] (1) The nickel substrate is pretreated to remove oil stains and surface oxides.

[0008] The nickel substrate is a commercially available twill nickel mesh, a stretched diamond nickel mesh, a nickel foam mesh or a nickel fiber felt material.

[0009] The pre-treatment is achieved by chemical degreasing, pickling or sand blasting cleaning.

[0010] (2) A mixed solution mainly composed of a nickel salt and insoluble metal oxide nanoparticles is configured and uniformly dispersed by ultrasonic stirring; then the treated nickel substrate is used as a working electrode, the configured mixed solution is used as a deposition solution, and electrochemical deposition is performed, so that a transition composite layer (intermediate layer) of nickel metal and metal oxide is pre-deposited on the nickel substrate.

[0011] The nickel salt is one of nickel chloride, nickel nitrate, nickel acetate and nickel sulfate, and the concentration range is 10-500 mM.

[0012] The insoluble metal oxide (MO x ) is one or two of titanium dioxide, cerium dioxide, zirconium dioxide, hafnium dioxide, niobium pentoxide, tantalum pentoxide and chromium trioxide, and the mass concentration range is 0.2-10 g / L.

[0013] The mixed solution also contains trisodium citrate and a surfactant, wherein the concentration range of trisodium citrate is 5-300 mM; the surfactant is one of polyvinylpyrrolidone, sodium dodecyl sulfonate or sodium benzoate, and the concentration range is 0.1-5 g / L.

[0014] The electrochemical deposition is achieved by constant current to reduce nickel ions and co-deposit metal oxides, and the applied cathode current density range is 10-500 mA cm-2, and the deposition time is 10-120 min.

[0015] (3) After step 2 is completed, a molybdenum salt solution or a mixed solution of molybdenum salt and tungsten salt is continuously added to the deposition solution, and after uniform stirring, two-stage electrodeposition is performed to further deposit a high-activity outer layer of nickel-molybdenum (or nickel-molybdenum-tungsten) and metal oxides on the outer layer.

[0016] The molybdenum salt refers to ammonium molybdate and sodium molybdate, and the concentration range of the molybdenum salt is 5-300 mM; the tungsten salt refers to ammonium tungstate, ammonium metatungstate and sodium tungstate, and the concentration range of the tungsten salt is 3-200 mM.

[0017] The two-stage electrodeposition is achieved by constant current to reduce nickel ions, molybdenum ions and co-deposit metal oxides, and the applied current density is 10-500 mA cm-2, and the deposition time is 15-120 min.

[0018] (4) After step 3 is completed, the electrode is taken out for drying, and finally a composite electrode of nickel-molybdenum or nickel-molybdenum-tungsten and metal oxides is obtained.

[0019] The drying is one of vacuum drying or air blowing drying.

[0020] The prepared hydrogen evolution electrode of the nickel alloy-metal oxide composite hydrogen evolution electrode preparation method of the application is mainly applied to alkaline water electrolysis hydrogen production, hydroxyl ion exchange membrane electrolysis hydrogen production, chlor-alkali industry, etc.

[0021] The prepared electrode material has a Ni-MO x The intermediate layer of the composite oxide reduces the stress between the outer catalytic layer and the substrate, reduces the mismatch of the active layer and the substrate, and improves the bonding force between the substrate; the outer deposited nickel-molybdenum (or nickel-molybdenum-tungsten) and the metal oxide composite active layer not only improves the reaction area and active sites, but also further improves the stability of the electrode; the hydrogen evolution electrode has the advantages of high current density, low overpotential, and good stability.

[0022] The hydrogen evolution electrode preparation process is simple and easy to operate, has no high temperature and high pressure link, is safe and low in cost, is easy to industrialize, has excellent commercialization prospects. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 SEM image of the nickel-molybdenum-cerium dioxide composite hydrogen evolution electrode prepared by the application;

[0024] Figure 2 XRD image of the nickel-molybdenum-cerium dioxide composite hydrogen evolution electrode prepared by the application;

[0025] Figure 3 SEM image of the nickel-molybdenum-tungsten-zirconium dioxide composite hydrogen evolution electrode prepared by the application;

[0026] Figure 4 XRD image of the nickel-molybdenum-tungsten-zirconium dioxide composite hydrogen evolution electrode prepared by the application;

[0027] Figure 5 Electrochemical polarization curve comparison chart of (1) nickel-molybdenum-cerium dioxide composite hydrogen evolution electrode, (2) nickel-molybdenum-tungsten-zirconium dioxide composite hydrogen evolution electrode, (3) commercial Pt / C, and (4) commercial nickel substrate electrode prepared by the application.

[0028] Figure 6 Constant current step comparison chart of (1) nickel-molybdenum-cerium dioxide composite hydrogen evolution electrode, (2) nickel-molybdenum-tungsten-zirconium dioxide composite hydrogen evolution electrode, (3) commercial Pt / C, and (4) commercial nickel substrate electrode prepared by the application. DETAILED DESCRIPTION

[0029] The technical solutions in the present application will be described clearly and completely below in combination with the embodiments in the present application, but they should not be understood as limitations to the protection scope of the present application.

[0030] Example 1

[0031] (1) A commercial twill nickel mesh electrode with a size of 10 cm*10 cm was subjected to ultrasonic oil removal treatment in a 0.5M sodium carbonate-0.5 sodium hydroxide mixed solution at room temperature for 30 min. After the oil removal was completed, the residual oil removal liquid was washed away with deionized water. Then, the oil-removed twill nickel mesh was subjected to ultrasonic acid pickling in a 10% HCl solution for 10 min. After the acid pickling was completed, the twill nickel mesh was rinsed and air-dried with deionized water.

[0032] (2) A mixed solution of 2 g / L CeO2, 100 mM nickel chloride, 100 mM trisodium citrate, and 0.5 g / L polyvinylpyrrolidone was configured, and ultrasonic dispersion was performed for 30 min to uniformly suspend the CeO2 particles in the hot mixed solution. Then, the twill nickel mesh after surface treatment was used as the working electrode, a commercial titanium mesh was used as the auxiliary electrode, and the mixed solution was used as the electrochemical deposition liquid. Under stirring conditions, a cathode current of 15 A was applied for 30 min. A nickel substrate with a deposited Ni-CeO2 composite intermediate layer (Ni-CeO2 / Ni) was obtained.

[0033] (3) In the electrolyte after step 2 was performed, 20 mM ammonium molybdate solution was added. Under stirring conditions, a cathode current of 10 A was then continuously applied for 40 min. Finally, a nickel molybdenum-cerium dioxide composite hydrogen evolution electrode, designated as NiMo-CeO2 / Ni-CeO2 / Ni (abbreviated as NiMo-CeO2 / Ni), was obtained.

[0034] The SEM and XRD characterizations of the NiMo-CeO2 / Ni composite hydrogen evolution electrode prepared in this example are shown in Figure 1 and Figure 2 .

[0035] Example 2

[0036] (1) A commercial twill nickel mesh electrode with a size of 10 cm*10 cm was subjected to ultrasonic oil removal treatment in a 0.5M sodium carbonate-0.5 sodium hydroxide mixed solution at room temperature for 30 min. After the oil removal was completed, the residual oil removal liquid was washed away with deionized water. Then, the oil-removed twill nickel mesh was subjected to ultrasonic acid pickling in a 10% HCl solution for 20 min. After the acid pickling was completed, the twill nickel mesh was rinsed and air-dried with deionized water.

[0037] (2) The mixed solution of 1 g / L ZrO2, 100 mM nickel chloride, 100 mM trisodium citrate, and 0.3 g / L sodium dodecyl sulfate is prepared and ultrasonically dispersed for 30 minutes to make the ZrO2 particles uniformly suspended in the hot mixed solution. Then, the surface-treated twilled nickel mesh is used as the working electrode, the commercial titanium mesh is used as the auxiliary electrode, and the mixed solution is used as the electrochemical deposition solution. Under stirring, a cathode current of 4 A is applied for 20 min. A nickel substrate with a deposited Ni-ZrO2 composite intermediate layer (Ni-ZrO2 / Ni) is obtained.

[0038] (3) In the electrolyte prepared in step 2, an equal volume of a mixed solution of 10 mM ammonium molybdate and 10 mM sodium tungstate is added. Under stirring, a cathode current of 3 A is then continuously applied for 30 min. Finally, a composite hydrogen evolution electrode loaded with nickel molybdenum tungsten-cerium dioxide, named NiMoW-ZrO2 / Ni-ZrO2 / Ni (abbreviated as NiMoW-ZrO2 / Ni), is obtained.

[0039] The SEM and XRD characterizations of the NiMoW-ZrO2 / Ni composite hydrogen evolution electrode prepared in this example are shown in Figure 3 and Figure 4 .

[0040] The NiMo-CeO2 / Ni composite hydrogen evolution electrode prepared in (1), the NiMoW-ZrO2 / Ni composite hydrogen evolution electrode prepared in (2), the nickel substrate coated with commercial Pt / C in (3), and the commercial nickel substrate in (4) are used as the working electrode, respectively, for three-electrode testing. The electrolyte is 1 M potassium hydroxide, and the electrolysis temperature is 25°C. The LSV curves of the four are shown in Figure 5 The NiMo-CeO2 / Ni composite hydrogen evolution electrode and the NiMoW-ZrO2 / Ni composite hydrogen evolution electrode of the application not only exhibit low overpotential and high current density characteristics close to those of the commercial Pt / C catalyst, but also verify the high activity and high stability of the hydrogen evolution performance of the NiMo-CeO2 / Ni composite hydrogen evolution electrode and the NiMoW-ZrO2 / Ni composite hydrogen evolution electrode comparable to or even superior to the commercial Pt / C in the Figure 6 step test.

[0041] The above only describes the preferred embodiments of the application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the application, and these improvements and refinements should also be considered within the protection scope of the application.

Claims

1. A method for preparing a nickel alloy-metal oxide composite hydrogen evolution electrode, characterized in that, Includes the following steps: (1) Pretreatment of the nickel substrate to remove oil and surface oxides; (2) A mixture of soluble nickel salt and insoluble metal oxide nanoparticles is prepared and ultrasonically stirred to disperse it evenly. Using the treated nickel substrate as the working electrode and the prepared mixture as the deposition solution, electrochemical deposition is performed. Through this step, an intermediate composite layer of nickel metal and metal oxide is pre-deposited on the nickel substrate. The insoluble metal oxide is one or two of titanium dioxide, cerium dioxide, zirconium dioxide, hafnium dioxide, niobium pentoxide, tantalum pentoxide, and chromium trioxide, with a concentration range of 0.2 to 10 g / L. The soluble nickel salt is one of nickel chloride, nickel nitrate, nickel acetate, and nickel sulfate, with a concentration range of 10 to 500 mM. The mixture also contains trisodium citrate and a surfactant, with the concentration range of trisodium citrate being 5 to 300 mM. The surfactant is one of polyvinylpyrrolidone, sodium dodecyl sulfonate, or sodium benzoate, with a concentration range of 0.1 to 5 g / L. (3) After step 2 is completed, molybdenum salt solution or a mixed solution of molybdenum salt and tungsten salt is added to the original deposition solution. After stirring evenly, a second-stage electrodeposition is performed to further deposit a highly active outer layer of nickel-molybdenum and metal oxide, or nickel-molybdenum-tungsten and metal oxide. The molybdenum salt mentioned in step (3) refers to ammonium molybdate and sodium molybdate, and the concentration range of molybdenum salt is 5 to 300 mM. The tungsten salt refers to ammonium tungstate, ammonium metatungstate, and sodium tungstate, and the concentration range of tungsten salt is 3 to 200 mM. (4) After step 3 is completed, the electrode is removed and dried to obtain a composite electrode of nickel-molybdenum and metal oxide, or a composite electrode of nickel-molybdenum-tungsten and metal oxide.

2. The method for preparing a nickel alloy-metal oxide composite hydrogen evolution electrode according to claim 1, characterized in that, The nickel substrate mentioned in step (1) is a commercially available twill nickel mesh, stretched diamond nickel mesh, foamed nickel mesh or nickel fiber felt material.

3. The method for preparing a nickel alloy-metal oxide composite hydrogen evolution electrode according to claim 1, characterized in that, The electrochemical deposition described in step (2) uses a constant current to achieve the reduction of nickel ions and the co-deposition of metal oxides. The applied cathode current density is 10 to 500 mA cm⁻², and the deposition time is 10 to 120 min.

4. The method for preparing a nickel alloy-metal oxide composite hydrogen evolution electrode according to claim 1, characterized in that, The two-stage electrodeposition described in step (3) uses a constant current to achieve the reduction of nickel ions and molybdenum ions and the co-deposition of metal oxides. The applied current density is 10 to 500 mA cm⁻², and the deposition time is 15 to 120 min.

5. The method for preparing a nickel alloy-metal oxide composite hydrogen evolution electrode according to claim 1, characterized in that, The drying process is either vacuum drying or forced-air drying, and the drying temperature is between room temperature and 100°C.

6. The application of the hydrogen evolution electrode prepared by the method of preparing a nickel alloy-metal oxide composite hydrogen evolution electrode according to any one of claims 1 to 5 in the electrolysis of water to produce hydrogen.

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