Preparation method of non-noble metal doped nickel-molybdenum-nitrogen-carbon multi-element hydrogen evolution catalyst

Abstract

The invention discloses a preparation method of a non-noble metal doped nickel-molybdenum-nitrogen-carbon multi-element hydrogen evolution catalyst. Comprising the following steps: 1) preparing a mixed solution of a nickel salt and a non-noble metal (the non-noble metal is one of gallium, zirconium and chromium) salt, and a molybdenum salt solution, and adjusting the pH value of the molybdenum salt solution; (2) adding a mixed solution of nickel salt and non-noble metal (gallium or zirconium or chromium) salt into the molybdenum salt solution, stirring, carrying out suction filtration, washing and drying to obtain a non-noble metal doped nickel molybdate-nickel hydroxide solid intermediate; and 3) placing the obtained intermediate in an atmosphere furnace, carrying out high-temperature heat treatment in an atmosphere containing nitrogen, carbon and hydrogen, and carrying out reduction, nitridation, carbonization and carbon deposition reactions, so that the obtained catalyst has the hydrogen evolution catalytic performance similar to that of a noble metal Pt / C catalyst, is excellent in durability, and can significantly reduce the overpotential of the hydrogen evolution reaction of electrolyzed water. Moreover, the multi-element hydrogen evolution catalyst is low in cost, simple in preparation process and suitable for large-scale industrial production.

Description

Technical Field

[0001] The present invention relates to the field of electrode materials, and particularly to a preparation method of a non-noble metal-doped nickel-molybdenum-nitrogen-carbon multi-component hydrogen evolution catalyst. Background Art

[0002] Renewable energy electrolysis of water to produce hydrogen is an important way to obtain green hydrogen. The electrolysis of water reaction consists of an anodic oxygen evolution reaction and a cathodic hydrogen evolution reaction. The overpotentials on the anode and cathode, the solution ohmic voltage drop, and the theoretical voltage are the main components of the actual voltage of water electrolysis. In order to reduce the electrolytic hydrogen production voltage and improve the hydrogen production efficiency, researchers use highly active catalysts to reduce the overpotential and increase the current density. Patent CN202211064473.9 discloses a preparation method of a nickel-molybdenum-tungsten supported porous nickel-based self-supporting catalytic hydrogen evolution cathode material. In this method, porous nickel foam (NF) is used as the substrate, and the substrate is modified with a nickel-molybdenum-tungsten ternary alloy coating by electrochemical deposition and heat-treated to obtain the final NiMoW@NF hydrogen evolution electrode. CN202310066730.0 discloses a three-dimensional honeycomb porous carbon-supported nickel-molybdenum-nitrogen composite material and its preparation method. This material is a composite material formed by in-situ loading a nanoscale nickel-molybdenum-nitrogen catalyst on the porous carbon wall with a three-dimensional honeycomb structure and nanoscale porous carbon as a high-surface-area and high-conductivity substrate. In these patents, the prepared nickel-molybdenum-tungsten catalyst or nickel-molybdenum-nitrogen catalyst has high hydrogen evolution activity. However, due to the limitation of the coating surface area, the hydrogen evolution activity of the materials prepared by electrodeposition needs to be further improved; the three-dimensional porous carbon has a high cost due to the need to be prepared by freeze-drying method, and due to the easy oxidation and dissolution of the Mo element in the above catalysts, the stability of such electrodes is insufficient.

[0003] In summary, the current hydrogen evolution catalysts have problems such as high production cost or insufficient hydrogen evolution activity and stability of the produced electrodes. Summary of the Invention

[0004] In view of this, the present invention provides a preparation method of a non-noble metal-doped nickel-molybdenum-nitrogen-carbon multi-component hydrogen evolution catalyst. The present invention adopts the following specific scheme:

[0005] (1) Prepare a mixed solution of a nickel salt and a non-noble metal (non-noble metal M = Ga or Zr or Cr) salt, and a molybdenum salt solution, and adjust the pH value of the molybdenum salt solution. The non-noble metal salt used is one of gallium chloride, gallium sulfate, zirconium nitrate, zirconium sulfate, zirconium acetate, chromium chloride, and chromium nitrate, and the nickel salt is one of nickel chloride, nickel nitrate, nickel acetate, and nickel sulfate. The concentration range of the nickel salt is 0.1-2M, and the concentration ratio of the gallium salt (or zirconium salt or chromium salt) to the nickel salt is 1:10-80. The molybdenum salt used refers to one of ammonium molybdate and sodium molybdate, and its concentration range is 0.1-2M; the pH range of the molybdenum salt solution after adding alkali is 4.5-8.

[0006] (2) Add the mixed solution of gallium salt (or zirconium salt or chromium salt) and nickel salt to the molybdate solution with adjusted pH. After stirring at a certain temperature for a certain time, perform suction filtration, rinsing, and drying to obtain the gallium-doped nickel molybdate-nickel hydroxide solid intermediate (M / NiMoO 4 -Ni(OH) 2 ). The molar ratio of cations in the mixed solution of gallium salt (zirconium salt) and nickel salt to the amount of molybdate in the molybdate solution is 0.7 - 5:1. The temperature range of this reaction is room temperature to 120 °C, and the stirring duration range is 0.5 - 6 h.

[0007] (3) Place the obtained M / NiMoO 4 -Ni(OH) 2 in an atmosphere furnace. Under an atmosphere containing nitrogen, carbon, and hydrogen, perform high-temperature heat treatment to carry out reduction, nitridation, and carbonization reactions to obtain the gallium-doped nickel molybdenum nitrogen carbon catalyst (M / NiMoNC). The high-temperature heat treatment temperature range is 400 - 800 °C, and the duration range is 0.5 - 6 h. In the said atmosphere furnace, nitrogen or argon is introduced as the carrier gas. At the same time, the furnace is pre-loaded with one or two of dicyandiamide, urea, and melamine solids. Through high-temperature thermal decomposition, a mixed gas containing nitrogen, carbon, and hydrogen is generated to realize the reduction, nitridation, carbonization, and carbon deposition of the M / NiMoO 4 -Ni(OH) 2 intermediate to obtain a multi-component hydrogen evolution catalyst of gallium (or zirconium or chromium) -doped nickel molybdenum nitrogen carbon.

[0008] For the electrode material prepared by the present invention, Ga or Zr or Cr doping regulates the electron density at the active sites of nickel molybdenum nitride, refines the grain size, introduces a large number of defects and heterojunctions, which helps to improve the hydrogen evolution activity; in addition, the electron-donating effect of Ga or Zr or Cr and the formed oxides also inhibit the oxidation of nickel and molybdenum; furthermore, carbonization and nitridation also improve the oxidation resistance of nickel molybdenum. Finally, carbon deposition forms a carbon protection layer on the surface of the catalyst, further enhancing the stability and durability of the catalyst.

[0009] The gallium (or zirconium or chromium) -doped nickel molybdenum nitrogen carbon multi-component hydrogen evolution catalyst provided by the present invention has the remarkable advantages of low hydrogen evolution overpotential, high current density, and good durability. This hydrogen evolution catalyst has broad application value in alkaline water electrolysis, proton exchange membrane water electrolysis, anion exchange membrane water electrolysis for hydrogen production, and chlor-alkali electrolytic cells.

[0010] The preparation method of the gallium (or zirconium or chromium) -doped nickel molybdenum nitrogen carbon multi-component hydrogen evolution catalyst provided by the present invention has the characteristics of being simple and easy to operate, low cost, high yield, and easy to scale up industrially, and thus has excellent industrialization value. Description of the Drawings

[0011] Figure 1 SEM image of the Ga / NiMoNC multi-component hydrogen evolution catalyst prepared according to Case 1 of the present invention;

[0012] Figure 2 SEM image of the Zr / NiMoNC multi-component hydrogen evolution catalyst prepared according to Case 2 of the present invention;

[0013] Figure 3 SEM image of the Cr / NiMoNC multi-component hydrogen evolution catalyst prepared according to Case 2 of the present invention;

[0014] Figure 4 Linear voltammetry curve comparison diagram of the Ga / NiMoNC hydrogen evolution cathode, (2) Zr / NiMoNC hydrogen evolution cathode, (3) Cr / NiMoNC hydrogen evolution cathode prepared according to the examples of the present invention, and the comparative samples including (4) NiMoNC, (5) commercial Pt / C hydrogen evolution cathode, and (6) commercial nickel foam hydrogen evolution cathode.

[0015] Figure 5 Current step curve comparison diagram of the Ga / NiMoNC hydrogen evolution cathode, (2) Zr / NiMoNC hydrogen evolution cathode, (3) Cr / NiMoNC hydrogen evolution cathode prepared according to the examples of the present invention, and the comparative samples including (4) NiMoNC hydrogen evolution cathode, (5) commercial Pt / C hydrogen evolution cathode, and (6) commercial nickel foam hydrogen evolution cathode. Detailed implementation method

[0016] Next, the technical solutions in the present invention will be clearly and completely described in combination with the embodiments in the present invention, but they cannot be understood as limiting the protection scope of the present invention.

[0017] Example 1

[0018] (1) Prepare a mixed solution A of 60 mM gallium chloride and 1.2 M nickel nitrate, prepare a 1 M ammonium molybdate solution B, and adjust the pH value of the ammonium molybdate solution to 6.5.

[0019] (2) At 50 °C, add 200 mL of the mixed solution A to 200 mL of the solution B, and stir for 3 h; then perform suction filtration, rinsing, and drying to obtain the precursor Ga / NiMoO 4 -Ni(OH) 2 .

[0020] (3) Weigh 2 g of the above precursor Ga / NiMoO 4 -Ni(OH) 2It was placed in a tubular atmosphere furnace, and a mixed solid of 2 g of urea and 2 g of dicyandiamide was pre-added to the tubular furnace. Nitrogen was introduced as the carrier gas, and then the temperature was raised to 650 °C at a heating rate of 10 K / min and kept at a constant temperature for 2 h to obtain Ga / NiMoNC.

[0021] The SEM electron microscopy characterization of the Ga / NiMoNC multi-component hydrogen evolution catalyst prepared in this example is as Figure 1 shown.

[0022] Example 2

[0023] (1) Prepare a mixed solution A of 100 mM zirconium chloride and 1.5 M nickel nitrate, prepare a solution B of 1.2 M ammonium molybdate, and adjust the pH value of the ammonium molybdate solution to 7.5.

[0024] (2) At room temperature, add 100 mL of the mixed solution A to 100 mL of the solution B and stir for 6 h; then perform suction filtration, rinsing, and drying to obtain the precursor Zr / NiMoO 4 -Ni(OH) 2 .

[0025] (3) Weigh 6 g of the above precursor Zr / NiMoO 4 -Ni(OH) 2 Place it in a tubular atmosphere furnace, and pre-add a mixed solid of 5 g of urea and 10 g of dicyandiamide to the tubular furnace. Introduce nitrogen as the carrier gas, and then raise the temperature to 550 °C at a heating rate of 5 K / min and keep it at a constant temperature for 2 h to obtain Zr / NiMoNC.

[0026] The SEM electron microscopy characterization of the Zr / NiMoNC multi-component hydrogen evolution catalyst prepared in this example is as Figure 3 shown.

[0027] Example 3

[0028] (1) Prepare a mixed solution A of 20 mM chromium chloride and 1 M nickel nitrate, prepare a solution B of 0.8 M ammonium molybdate, and adjust the pH value of the ammonium molybdate solution to 8.

[0029] (2) At room temperature, add 100 mL of the mixed solution A to 100 mL of the solution B and stir for 8 h; then perform suction filtration, rinsing, and drying to obtain the precursor Cr / NiMoO 4 -Ni(OH) 2 .

[0030] (3) Weigh 5 g of the above precursor Cr / NiMoO 4 -Ni(OH) 2It was placed in a tubular atmosphere furnace, and a mixed solid of 4 g of urea and 6 g of dicyandiamide was pre-added to the tubular furnace. Nitrogen was introduced as a carrier gas, and then it was heated to 600 °C at a heating rate of 8 K / min and kept at a constant temperature for 2 h to obtain Cr / NiMoNC.

[0031] The SEM characterization of the Cr / NiMoNC multi-component hydrogen evolution catalyst prepared in this example is as Figure 3 shown.

[0032] The above-prepared Ga / NiMoNC, Zr / NiMoNC, Cr / NiMoNC and commercial Pt / C were respectively dispersed in a 2 mg / mL Nafion solution and sonicated for 30 min, and then the sonicated slurry was evenly drop-coated on the pretreated nickel foam (NF) substrate. After drying, it was weighed, and their loadings were controlled to be 8 ± 0.2 mg cm -2 , to obtain (1) Ga / NiMoNC hydrogen evolution cathode, (2) Zr / NiMoNC hydrogen evolution cathode, (3) Cr / NiMoNC hydrogen evolution cathode and the comparative sample (4) undoped NiMoNC hydrogen evolution cathode (other preparation conditions are the same as in Example 1), (5) commercial Pt / C hydrogen evolution cathode. In addition, the commercial nickel foam substrate was used as another comparative hydrogen evolution cathode (6). Using the above electrodes as working electrodes, a three-electrode test of hydrogen evolution performance was carried out. The electrolyte was 1 M potassium hydroxide and the temperature was room temperature. The LSV curves of the four are as Figure 4 shown. Figure 4 It shows that the Ga / NiMoNC hydrogen evolution cathode, Zr / NiMoNC hydrogen evolution cathode, and Cr / NiMoNC hydrogen evolution cathode prepared by the present invention exhibit low overpotential and high current density characteristics close to those of commercial Pt / C catalysts. Figure 5 It shows that in the step test, the Ga / NiMoNC hydrogen evolution cathode, Zr / NiMoNC hydrogen evolution cathode, and Cr / NiMoNC hydrogen evolution cathode all exhibit low overpotential and high stability characteristics. Figure 4 and Figure 5 The data has no post-voltage drop compensation and is compared under the same conditions.

[0033] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a non-precious metal doped nickel, molybdenum, nitrogen and carbon multicomponent hydrogen evolution catalyst. It is characterized in that: The following steps are involved: (1) preparing a mixed solution of nickel salt and non-precious metal salt (non-precious metal M is one of gallium, zirconium and chromium) and a molybdenum salt solution, and adjusting the pH value of the molybdenum salt solution; (2) adding a mixed solution of nickel salt and non-precious metal salt to a molybdenum salt solution after adjusting the pH, stirring at a certain temperature, filtering, rinsing, and drying to obtain a non-precious metal-doped nickel molybdate-nickel hydroxide solid intermediate; (3) placing the obtained intermediate in an atmosphere furnace and subjecting it to high-temperature heat treatment in an atmosphere containing nitrogen, carbon and hydrogen to cause reduction, nitridation, carbonization and carbon deposition reactions, thereby obtaining a non-precious metal (gallium or zirconium or chromium) doped nickel-molybdenum-nitrogen-carbon multi-element hydrogen evolution catalyst.

2. The method for preparing a non-noble metal doped nickel-molybdenum-nitrogen-carbon multicomponent hydrogen evolution catalyst according to claim 1, characterized in that: The non-precious metal salt described in step (1) is one of gallium chloride, gallium sulfate, zirconium nitrate, zirconium sulfate, zirconium acetate, chromium chloride, and chromium nitrate; the nickel salt is one of nickel chloride, nickel nitrate, nickel acetate, and nickel sulfate; the concentration range of the nickel salt is 0.1 to 2M; and the concentration ratio of the gallium salt (or zirconium salt or chromium salt) to the nickel salt is 1:10 to 80.

3. The method for preparing a non-noble metal doped nickel-molybdenum-nitrogen-carbon multicomponent hydrogen evolution catalyst according to claim 1, characterized in that: The molybdenum salt in step (1) refers to one of ammonium molybdate and sodium molybdate, and its concentration range is 0.1-2M; the pH range after adjustment with alkali is 4.5-8.

4. The method for preparing a non-noble metal doped nickel-molybdenum-nitrogen-carbon multicomponent hydrogen evolution catalyst according to claim 1, characterized in that: The ratio of the amount of cationic substances in the mixed solution of gallium salt (or zirconium salt or chromium salt) and nickel salt to the amount of molybdate anion substances in the molybdenum salt solution described in step (2) is 0.7 to 5:

1.

5. The method for preparing a non-noble metal doped nickel-molybdenum-nitrogen-carbon multicomponent hydrogen evolution catalyst according to claim 1, characterized in that: The temperature range of step (2) is room temperature to 120° C., and the stirring time is 0.5 to 6 hours.

6. The method for preparing a non-noble metal doped nickel-molybdenum-nitrogen-carbon multicomponent hydrogen evolution catalyst according to claim 1, characterized in that: The high temperature heat treatment described in step (3) has a temperature range of 400 to 800° C. and a duration range of 0.5 to 6 hours.

7. The method for preparing a non-noble metal doped nickel-molybdenum-nitrogen-carbon multicomponent hydrogen evolution catalyst according to claim 1, characterized in that: In step (3), nitrogen or argon is introduced into the atmosphere furnace as a carrier gas, and one or two of dicyandiamide, urea and melamine solids are simultaneously contained in the furnace, and the solids are decomposed by high temperature to generate a mixed gas containing nitrogen, carbon and hydrogen, thereby achieving reduction, nitridation and carbon deposition of the non-precious metal-doped nickel molybdate-nickel hydroxide solid intermediate, and obtaining a Ga or Zr or Cr-doped nickel-molybdenum-nitrogen-carbon multi-element hydrogen evolution catalyst.

8. Use of the hydrogen evolution catalyst prepared by the method for preparing a non-noble metal-doped nickel-molybdenum-nitrogen-carbon multi-component hydrogen evolution catalyst according to any one of claims 1 to 7 in alkaline water electrolysis, proton exchange membrane water electrolysis, anion exchange membrane water electrolysis and hydrogen production in chlor-alkali electrolysis cells.

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