Preparation method and application of carbon-nitrogen carrier loaded ruthenium-nickel nanometer alloy electrocatalytic material

Abstract

This invention discloses a method for preparing ruthenium-nickel nano-alloy electrocatalytic materials supported on a carbon-nitrogen support and their applications. Melamine is dispersed in an organic solvent and stirred until homogeneous. Then, 1,5-diaminopentane is added and stirred until homogeneous to obtain solution A. Ruthenium and nickel salts are added to the organic solvent and ultrasonically treated to obtain solution B. Solution B is slowly poured into solution A and stirred to react. After the reaction, the mixture is allowed to stand until a stable precipitate forms. The obtained precipitate is separated, washed, and dried to obtain a powdered precursor. The powdered precursor is subjected to a pyrolysis reaction to obtain a primary catalytic material. The obtained primary catalytic material is immersed in hydrochloric acid solution and dried to constant weight to obtain a carbon-nitrogen supported ruthenium-nickel nano-alloy electrocatalytic material, i.e., a binary alloy Ni. x Ru 2‑x / NC catalyst. The catalyst prepared by this invention exhibits extremely excellent catalytic performance in acidic, neutral, and alkaline water electrolysis hydrogen evolution reactions, and its hydrogen evolution activity is significantly superior to that of commercial platinum-carbon catalysts.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalytic material preparation and hydrogen energy development and application technology. Specifically, it relates to a method for preparing ruthenium-nickel nano-alloy electrocatalytic material supported on a carbon-nitrogen carrier with controllable lattice compression and its application in the hydrogen production reaction of water electrolysis. It is particularly suitable for efficient and stable water electrolysis hydrogen production scenarios in acidic, neutral and alkaline systems. Background Technology

[0002] Hydrogen energy, as a clean, efficient, and sustainable secondary energy source, possesses core advantages such as high energy density and pollution-free combustion products. It is a key direction for addressing global energy shortages and environmental pollution, and the demand for large-scale market applications is increasingly urgent. Electrolysis of water for hydrogen evolution has become the preferred route for large-scale green hydrogen production due to the wide availability of water as a raw material and the high purity of the produced hydrogen. However, the hydrogen evolution reaction faces kinetic barriers, requiring highly efficient catalysts to lower these barriers. Therefore, developing high-performance, low-cost hydrogen evolution catalysts is a core bottleneck in promoting the industrialization of water electrolysis for hydrogen production technology.

[0003] Platinum-based catalysts are currently the benchmark catalytic materials for hydrogen evolution reactions (HERs), but their scarcity in the Earth's crust and high production costs severely restrict the large-scale application of water electrolysis for hydrogen production. Ruthenium (Ru), as a platinum group metal, has higher crustal abundance than platinum, is more economical, and exhibits catalytic activity similar to platinum in alkaline HERs. Furthermore, its surface hydrogen adsorption energy and the binding strength with reaction intermediates are better suited to the kinetics of alkaline HERs, making it an ideal candidate system to replace platinum-based catalysts. Therefore, structural modification and performance optimization of ruthenium-based catalysts have become a key research direction and a crucial technological breakthrough in the field of water electrolysis for hydrogen evolution.

[0004] Single ruthenium-based catalysts suffer from significant technical drawbacks: during alkaline hydrogen evolution reactions, their surfaces readily adsorb hydroxyl groups (-OH), leading to poisoning and the occupation of active sites, resulting in a continuous decline in catalytic activity. Furthermore, the electronic structure and lattice characteristics of pure ruthenium are not yet optimal for the hydrogen evolution reaction, and excessive amounts of precious metals still limit cost advantages. Alloying modification is an effective means to address these issues. Nickel (Ni), as an abundant and inexpensive transition metal, offers multiple technical advantages when alloyed with ruthenium: First, nickel has rapid dissociation and desorption capabilities for hydroxyl groups, precisely addressing the hydroxyl poisoning problem of ruthenium-based catalysts; second, the electronic structures of nickel and ruthenium are complementary, and alloying optimizes the electron centers of ruthenium through electron transfer effects, regulating the hydrogen adsorption free energy and improving catalytic kinetic efficiency; third, the introduction of nickel can significantly reduce the amount of precious metal ruthenium used, balancing cost control and catalytic activity; fourth, the alloy structure enhances the mechanical and chemical stability of the catalyst, preventing the aggregation and loss of active components during the reaction and extending its service life. Summary of the Invention

[0005] The technical problem this invention aims to solve is to address the two major technical pain points of existing ruthenium-based hydrogen evolution catalysts: insufficient stability and high cost. This invention provides a method for preparing ruthenium-nickel nano-alloy electrocatalytic materials supported on a carbon-nitrogen support and its applications. This invention achieves this by precisely controlling the molar ratio of nickel to ruthenium, enabling the two to form a binary alloy nanoparticle structure with controllable lattice compression on a carbon-nitrogen support. This structural design fully leverages the synergistic catalytic effect of ruthenium and nickel: lattice compression optimizes the electronic state distribution on the catalyst surface, improving the equilibrium efficiency of adsorption-desorption of reaction intermediates; the active sites of nickel and ruthenium form a complementary system, retaining the high hydrogen evolution activity of ruthenium while eliminating the risk of poisoning through the hydroxyl treatment ability of nickel, thereby achieving a synergistic improvement in catalytic performance.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a method for preparing ruthenium-nickel nano-alloy electrocatalytic materials supported on carbon and nitrogen carriers, the method comprising the following steps:

[0008] (1) Disperse the melamine precursor in an organic solvent and stir at room temperature (5-10 min) until the system is homogeneous; then add 1,5-diaminopentane to the homogeneous system and stir at room temperature (5-10 min) until homogeneous to obtain the precursor solution, i.e., solution A;

[0009] (2) Add ruthenium salt and nickel salt to an organic solvent, and sonicate until completely dissolved and mixed evenly to obtain a mixed solution of metal salts, i.e., solution B;

[0010] (3) Slowly pour the obtained solution B into solution A, stir the reaction at room temperature for 1 to 3 hours, and let it stand until a stable precipitate is formed after the reaction;

[0011] (4) Centrifuge the precipitate obtained in step (3) and collect the precipitate. Wash the precipitate with ethanol until the washing liquid is clear. Then place the washed product in a freeze dryer and dry it to constant weight to obtain a powdered precursor.

[0012] (5) The powdered precursor obtained in step (4) is placed in a tube furnace under argon atmosphere for pyrolysis: the temperature is raised to 700-900°C at a heating rate of 5-10°C / min, and kept at a constant temperature for 1.5-3.5h. After the holding time is completed, the temperature is naturally cooled to room temperature to obtain the primary catalyst material.

[0013] (6) The primary catalytic material obtained in step (5) is immersed in hydrochloric acid solution. After immersion, it is separated by vacuum filtration. The solid material is collected and dried with hot air to constant weight to obtain the carbon-nitrogen supported ruthenium-nickel alloy electrocatalytic material, i.e., the binary alloy Ni. x Ru 2-x / NC catalyst.

[0014] According to the above method for preparing ruthenium-nickel nano-alloy electrocatalytic materials supported on carbon and nitrogen, the organic solvent in step (1) is N-methylpyrrolidone (NMP), the molar volume ratio between melamine and organic solvent is 1 mmol: 15-35 mL, and the molar ratio between 1,5-diaminopentane and melamine is 1-2:1.

[0015] According to the above method for preparing ruthenium-nickel nano-alloy electrocatalytic materials supported on carbon-nitrogen carriers, the nickel salt in step (2) is nickel chloride, and the ruthenium salt is ruthenium chloride.

[0016] According to the above method for preparing ruthenium-nickel nano-alloy electrocatalytic materials supported on carbon and nitrogen, the molar ratio between melamine and ruthenium salt in step (1) is 2 to 4:1; the molar ratio between nickel salt and ruthenium salt in step (2) is 1:1 to 5.

[0017] The organic solvent mentioned in step (2) is N-methylpyrrolidone (NMP); the molar volume ratio between the sum of the ruthenium salt and the nickel salt and the organic solvent is 1 mmol: 60-80 mL.

[0018] According to the above method for preparing ruthenium-nickel nano-alloy electrocatalytic materials supported on carbon-nitrogen carriers, the standing time in step (3) is 3 to 6 hours.

[0019] According to the above method for preparing ruthenium-nickel nano-alloy electrocatalytic materials supported on carbon and nitrogen carriers, the powdered precursor in step (5) is placed in the middle constant temperature zone of a single-temperature zone tube furnace, and a sealed lid is placed on the quartz boat of the tube furnace before pyrolysis under an argon atmosphere.

[0020] According to the above preparation method of ruthenium-nickel nano-alloy electrocatalytic material supported on carbon and nitrogen, the argon gas flow rate in step (5) is controlled to be 50-200 sccm. Before the pyrolysis reaction is started, the quartz tube of the tube furnace is first purified by atmosphere treatment. High-purity argon gas with a purity of ≥99.999% is introduced at a flow rate of 500-650 sccm and continuously introduced for 10-30 min (to ensure that the residual air and other impurity gases in the quartz tube are completely replaced and removed). During the entire process of pyrolysis heating, constant temperature holding and natural cooling, the above-mentioned high-purity argon gas needs to be continuously introduced as a protective gas to maintain the stability of the inert atmosphere in the quartz tube and avoid oxidation or composition change of the pre-catalyst during the pyrolysis process.

[0021] According to the above method for preparing ruthenium-nickel nano-alloy electrocatalytic materials supported on carbon-nitrogen carriers, the concentration of the hydrochloric acid solution in step (6) is 1-3 mol / L, and the soaking time is 24-36 h.

[0022] The application of the ruthenium-nickel alloy electrocatalytic material supported on a carbon-nitrogen carrier prepared in this invention in the hydrogen production reaction by water electrolysis.

[0023] According to the above application, the ruthenium-nickel alloy electrocatalytic material supported on a carbon-nitrogen support prepared in this invention is used as a hydrogen evolution electrocatalyst to construct a working electrode for the hydrogen evolution reaction of water electrolysis.

[0024] The positive and beneficial effects of this invention are:

[0025] 1. Existing ruthenium-based catalysts are prone to active site poisoning due to hydroxyl adsorption during alkaline water electrolysis for hydrogen evolution. Furthermore, long-term reactions pose risks of active component aggregation and loss, making their stability unsatisfactory for practical applications. Simultaneously, the high dosage of pure ruthenium, a precious metal, leads to high catalyst costs, limiting large-scale deployment. This invention introduces nickel to reduce the amount of precious ruthenium used, thus controlling economic costs. Furthermore, the synergistic effect of nickel and ruthenium promotes the overflow and transfer of hydroxyl groups to nickel sites under alkaline conditions, alleviating the hydroxyl poisoning problem of ruthenium-based catalysts. The lattice compression effect formed by the nickel-doped ruthenium lattice allows for the adjustment of lattice spacing to suit the water dissociation reaction requirements, while simultaneously optimizing the catalyst's hydrophilicity. Ultimately, this achieves a simultaneous improvement in catalyst stability and catalytic activity.

[0026] 2. The ruthenium-nickel nano-alloy electrocatalytic material supported on a carbon-nitrogen carrier prepared by this invention is a nickel-ruthenium alloy hydrogen evolution catalyst that exhibits high activity, high stability, and high cost-effectiveness in acidic, neutral, and alkaline electrolytes and under step current densities. It breaks through the performance bottleneck of existing ruthenium-based catalysts, reduces the overall cost of hydrogen production through water electrolysis, provides core material support for the large-scale application of green hydrogen production technology, and promotes the widespread use of hydrogen energy in energy storage, transportation, industrial production, and other fields. It has significant industrial value and application prospects.

[0027] 3. The technical solution of this invention successfully synthesizes a carbon-nitrogen supported ruthenium-nickel nano-alloy electrocatalytic material, namely a binary alloy Ni, by combining wet impregnation with high-temperature calcination. x Ru 2-x / NC catalyst. Nickel doping induces a significant synergistic effect between nickel and ruthenium, greatly enhancing electrocatalytic performance. By controlling the nickel-ruthenium feed ratio, alloy catalysts with different lattice compression degrees can be prepared, achieving controllable lattice spacing, and the operation method is simple and easy to implement. This invention relates to a binary alloy Ni... 0.27 Ru 1.73The / NC catalyst exhibits excellent electrocatalytic performance and stability in acidic, alkaline, and neutral electrolytes. Under alkaline conditions, the overpotential is 74.2 mV and the Tafel slope is 39.2 mV·dec⁻¹ at a current density of 100 mA·cm⁻²; under acidic conditions, the overpotential is 90 mV and the Tafel slope is 42.27 mV·dec⁻¹; and under neutral conditions, its performance is superior to that of commercial platinum-carbon catalysts, demonstrating extremely high catalytic efficiency. Furthermore, after 250 hours of gradient current density stability testing in both acidic and alkaline electrolytes, its performance remains excellent compared to the initial value, indicating significant potential for practical applications. Attached Figure Description

[0028] Figure 1 Example 1 of this invention: Preparation of binary alloy Ni x Ru 2-x A schematic diagram of the synthetic route for the / NC catalyst.

[0029] Figure 2 The binary alloy Ni prepared in Example 1 of this invention 0.27 Ru 1.73 SEM image of the / NC catalyst;

[0030] Depend on Figure 2 It can be seen that the binary alloy Ni prepared by this invention 0.27 Ru 1.73 / NC catalysts exhibit a nanoparticle structure.

[0031] Figure 3 The binary alloy Ni prepared in Example 1 of this invention 0.27 Ru 1.73 Transmission electron microscopy (TEM) images and EDS mapping spectra of the / NC catalyst;

[0032] Depend on Figure 3 It can be seen that the binary alloy Ni prepared by this invention 0.27 Ru 1.73 The / NC catalyst exhibits a nanoparticle morphology with uniform C and N distribution. Ru and Ni are co-distributed on the carbon-nitrogen support without obvious separation, showing alloying / composite characteristics.

[0033] Figure 4 The (a) Ni prepared by this invention 0.27 Ru 1.73 / NC pickling XRD patterns before and after pickling;

[0034] Figure 4 in: (b) Ni x Ru 2-xXRD patterns of / NC and Ru NPs / NC; (c) XRD patterns of Ru NPs / NC and Ni NPs / NC; Figure 4 It can be seen that the binary alloy Ni prepared by this invention x Ru 2-x XRD results of the / NC catalyst show that the sample is mainly composed of Ru, and Ni doping causes the characteristic diffraction peaks of Ru to shift towards the higher 2θ direction.

[0035] Figure 5 The binary alloy Ni prepared in Example 1 of this invention 0.27 Ru 1.73 X-ray photoelectron spectroscopy of / NC catalyst Figure X PS;

[0036] Depend on Figure 5 It can be seen that the binary alloy Ni prepared by this invention x Ru 2-x XPS results for the / NC catalyst showed that electrons were transferred from ruthenium (Ru) atoms to nickel (Ni) atoms.

[0037] Figure 6 The catalysts prepared in Example 1, Comparative Example 1, and Comparative Example 2 of this invention were used in 1M KOH (a) Ni 0.27 Ru 1.73 LSVs of / NC, Ru NPs / NC, Ni NPs / NC and commercial Pt / C; (b) Ni x Ru 2-x / NC, Ru NPs / NC and LSVs of commercial Pt / C; (c) Ni x Ru 2-x Tafel slopes for / NC, Ru NPs / NC, and commercial Pt / C;

[0038] Depend on Figure 6 It can be seen that the binary alloy Ni prepared by this invention 0.27 Ru 1.73 The / NC catalyst exhibits excellent alkaline hydrogen evolution performance: at a current density of 100 mA·cm⁻², the overpotential is only 74.2 mV; the corresponding Tafel slope is 39.2 mV·dec⁻¹.

[0039] Figure 7 The catalysts prepared in Example 1, Comparative Example 1, and Comparative Example 2 of this invention were used in 0.5 M H2SO4 (a) Ni x Ru 2-x / NC, Ru NPs / NC and LSV of commercial Pt / C; (b) Ni 0.27 Ru 1.73 / NC, Ru NPs / NC, Ni NPs / NC and LSVs of commercial Pt / C; (c) Ni x Ru 2-x Tafel slopes for / NC, Ru NPs / NC, and commercial Pt / C;

[0040] Depend on Figure 7 It can be seen that the binary alloy Ni prepared by this invention 0.27 Ru 1.73 The / NC catalyst exhibits excellent acidic hydrogen evolution performance: at a current density of 100 mA·cm⁻², the overpotential is only 90 mV; the corresponding Tafel slope is 42.27 mV·dec⁻¹.

[0041] Figure 8 The catalysts prepared in Example 1, Comparative Example 1, and Comparative Example 2 of this invention in 1M PBS (a)Ni x Ru 2-x LSVs of / NC, Ru NPs / NC, Ni NPs / NC and commercial Pt / C; (b) Ni x Ru 2-x Tafel slopes for / NC, Ru NPs / NC, and commercial Pt / C;

[0042] Depend on Figure 8 It can be seen that the binary alloy Ni prepared by this invention 0.27 Ru 1.73 The / NC catalyst exhibits activity comparable to the commercial Pt / C benchmark while demonstrating superior Tafel kinetics.

[0043] Figure 9 The binary alloy Ni prepared in Example 1 of this invention 0.27 Ru 1.73 Stability test of / NC catalyst in 1M KOH;

[0044] Depend on Figure 9 It can be seen that the binary alloy Ni prepared by this invention 0.27 Ru 1.73 The catalytic activity of the / NC catalyst did not decrease significantly after a 300-hour gradient stability test.

[0045] Figure 10 The binary alloy Ni prepared in Example 1 of this invention 0.27 Ru 1.73 Stability test diagram of / NC catalyst in 0.5M H2SO4;

[0046] Depend on Figure 10 It can be seen that the binary alloy Ni prepared by this invention 0.27 Ru 1.73The catalytic activity of the / NC catalyst did not decrease significantly after a 300-hour gradient stability test. Detailed Implementation

[0047] The present invention will be further illustrated below with reference to the embodiments, but this does not limit the scope of protection of the technical solution of the present invention.

[0048] Example 1:

[0049] This invention relates to a binary alloy Ni 0.27 Ru 1.73 The preparation method of / NC catalyst, and its detailed steps are as follows:

[0050] (1) Weigh 1.34 mmol of melamine and add it to a beaker. Add 40 mL of N-methylpyrrolidone (NMP) to the beaker and stir at room temperature for 10 min. Measure 2 mmol of 1,5-diaminopentane solution and add it to the beaker. Stir at room temperature for 10 min to obtain the precursor solution, i.e., solution A.

[0051] (2) Take 0.134 mmol NiCl2 and 0.4 mmol RuCl3, dissolve them in 40 mL N-methylpyrrolidone (NMP) solution, and sonicate for 15 min until the chloride is completely dissolved to obtain solution B;

[0052] (3) Slowly add solution B to solution A and stir the reaction at room temperature for 1 hour; after the reaction, let it stand for 5 hours to form a stable precipitate;

[0053] (4) Centrifuge the precipitate obtained in step (3) and collect the precipitate. Wash the precipitate with ethanol until the washing liquid is clear. Then place the washed product in a freeze dryer and dry it to constant weight to obtain a powdered precursor.

[0054] (5) Before pyrolysis, impurity gases are removed from the atmosphere of the quartz tube in the tubular furnace. Argon gas with a purity of 99.999% is introduced at a flow rate of 650 sccm to remove other gases in the quartz tube. The introduction time is 10 min.

[0055] The powdered precursor obtained in step (4) was placed in a tube furnace under argon atmosphere protection for pyrolysis reaction (argon was continuously introduced as protective gas during the reaction, and the flow rate of argon as protective gas was 100 sccm). The temperature was increased to 800°C at a heating rate of 5°C / min and kept at a constant temperature for 2 hours. After the heat preservation reaction was completed, argon was continuously introduced until the temperature dropped to room temperature. The argon was then turned off and the temperature was allowed to drop naturally to room temperature to obtain the primary catalyst material.

[0056] (6) The primary catalyst material obtained in step (5) is placed in a 1M HCl solution and soaked at room temperature for 24 hours. After soaking, it is separated by vacuum filtration, the solid material is collected and dried with hot air to constant weight to obtain the carbon-nitrogen supported ruthenium-nickel alloy electrocatalytic material, i.e., the binary alloy Ni. 0.27 Ru 1.73 / NC catalyst.

[0057] Example 2:

[0058] Binary alloys of Ni with different nickel doping contents x Ru 2-x The preparation method of the / NC catalyst is basically the same as that in Example 1, except that:

[0059] In step (2): 0.4 mmol RuCl3 is weighed at a fixed rate, and the content of NiCl2 is changed by weighing 0.4 mmol NiCl2, 0.2 mmol NiCl2, 0.1 mmol NiCl2, or 0.08 mmol NiCl2 respectively, and Ni is obtained by pyrolysis. 0.33 Ru 1.67 / NC、Ni 0.29 Ru 1.71 / NC、Ni 0.25 Ru 1.75 / NC、Ni 0.19 Ru 1.81 / NC catalyst.

[0060] Comparative Example 1:

[0061] A method for preparing a Ru NPs / NC catalyst, the detailed steps of which are as follows:

[0062] (1) Weigh 1.34 mmol of melamine and add it to a beaker. Add 40 mL of NMP to the beaker and stir at room temperature for 10 min. Measure 2 mmol of 1,5-diaminopentane solution and add it to the beaker. Stir at room temperature for 15 min to obtain solution A.

[0063] (2) Take 0.4 mmol RuCl3, dissolve it in 40 mL NMP solution, and sonicate for 15 min until the chloride is completely dissolved to obtain solution B;

[0064] (3) Slowly add solution B to solution A and stir the reaction at room temperature for 1 hour; after the reaction, let it stand for 5 hours to obtain a stable precipitate;

[0065] (4) Centrifuge the precipitate obtained in step (3) and collect the precipitate. Wash the precipitate with ethanol until the washing liquid is clear. Then place the washed product in a freeze dryer and dry it to constant weight to obtain a powdered precursor.

[0066] (5) Before the pyrolysis reaction, the atmosphere of the quartz tube in the tubular furnace is decontaminated with impurities. Argon gas with a purity of 99.999% is introduced at a flow rate of 650 sccm to remove other gases in the quartz tube. The introduction time is 10 min.

[0067] The powdered precursor obtained in step (4) was placed in a tube furnace under argon atmosphere for pyrolysis reaction (argon was continuously introduced as a protective gas during the reaction; the argon flow rate used as the protective gas in step (4) was 100 sccm). During the heating process of the tube furnace, the heating rate was controlled at 5°C / min, the temperature was raised to 800°C, and the holding time was 2h. After the heat preservation reaction was completed, argon was continuously introduced until the temperature dropped to room temperature. The argon was then turned off and the temperature was allowed to drop naturally to room temperature to obtain the primary catalyst material.

[0068] (6) The primary catalyst material obtained in step (5) is placed in 1M HCl solution and soaked at room temperature for 24 hours. After soaking, it is separated by vacuum filtration, the solid material is collected and dried by hot air to constant weight to obtain the product Ru NPs / NC material.

[0069] Comparative Example 2:

[0070] A method for preparing a Ni NPs / NC catalyst is basically the same as that in Comparative Example 1, except that:

[0071] In step (2): Take 0.134 mmol of NiCl2;

[0072] Step (6) is removed to prepare the Ni NPs / NC catalyst.

[0073] The performance of the ruthenium-nickel nano-alloy electrocatalytic material supported on a carbon-nitrogen support prepared in this invention in the hydrogen production reaction by water electrolysis is tested as follows:

[0074] Electrochemical performance analysis was performed at room temperature using a three-electrode system on a CHI 760E electrochemical workstation (Shanghai Chenhua Instrument Co., Ltd.). To prepare the working electrode, 2 mg of catalyst powder and 0.2 mg of carbon black were mixed with 960 μL of ethanol and 40 μL of Nafion solution, followed by sonication for over 30 minutes to form a homogeneous catalyst slurry. 1 mL of this slurry was drop-coated onto 1 cm × 1 cm hydrophilic carbon paper, yielding a final catalyst loading of 1 mg / cm². -2 All measured potentials were converted to the reversible hydrogen electrode (RHE) scale using the following formula: E RHE = E SCE + 0.0592 × pH + 0.241 V or E RHE = E Hg / HgO+ 0.059 × pH + 0.098 V.

[0075] Alkalinity test: Measurements were performed in a standard three-electrode system using 1M KOH solution. The catalyst-supported carbon paper served as the working electrode, the Hg / HgO electrode as the reference electrode, and the carbon rod as the counter electrode. Both the counter and reference electrodes were rinsed with deionized water before testing. Overpotential and Tafel slope were obtained from linear sweep voltammetry (LSV) curves compensated for iR. Long-term stability tests were conducted on a CHI1140D electrochemical workstation (Shanghai Chenhua Instrument Co., Ltd.).

[0076] Acidity test: The measurement was performed in 0.5M H2SO4 solution, using carbon paper with catalyst supported as the working electrode, a saturated calomel electrode (SCE) as the reference electrode, and a carbon rod as the counter electrode.

[0077] Neutralization test: Measurements were performed in 1M phosphate-buffered saline (PBS) solution, using carbon paper with catalyst-supported electrode as the working electrode, Hg / HgO electrode as the reference electrode, and carbon rod as the counter electrode.

Claims

1. A method for preparing a ruthenium-nickel nano-alloy electrocatalytic material supported on a carbon-nitrogen carrier, characterized in that, The preparation method includes the following steps: (1) Disperse the melamine precursor in an organic solvent and stir at room temperature until the system is homogeneous; then add 1,5-diaminopentane to the homogeneous system and stir at room temperature until homogeneous to obtain the precursor solution, i.e., solution A. (2) Add ruthenium salt and nickel salt to an organic solvent, and sonicate until completely dissolved and mixed evenly to obtain a mixed solution of metal salts, i.e., solution B; (3) Slowly pour the obtained solution B into solution A, stir the reaction at room temperature for 1 to 3 hours, and let it stand until a stable precipitate is formed after the reaction; (4) Centrifuge the precipitate obtained in step (3) and collect the precipitate. Wash the precipitate with ethanol until the washing liquid is clear. Then place the washed product in a freeze dryer and dry it to constant weight to obtain a powdered precursor. (5) The powdered precursor obtained in step (4) is placed in a tube furnace under argon atmosphere for pyrolysis: the temperature is raised to 700-900°C at a heating rate of 5-10°C / min, and kept at a constant temperature for 1.5-3.5h. After the holding time is completed, the temperature is naturally cooled to room temperature to obtain the primary catalyst material. (6) The primary catalytic material obtained in step (5) is immersed in hydrochloric acid solution. After immersion, it is separated by vacuum filtration. The solid material is collected and dried with hot air to constant weight to obtain the carbon-nitrogen supported ruthenium-nickel alloy electrocatalytic material, i.e., the binary alloy Ni. x Ru 2-x / NC catalyst.

2. The method for preparing the ruthenium-nickel nano-alloy electrocatalytic material supported on a carbon-nitrogen support according to claim 1, characterized in that: The organic solvent mentioned in step (1) is N-methylpyrrolidone (NMP), and the molar volume ratio between melamine and the organic solvent is 1 mmol: 15-35 mL; the molar ratio between 1,5-diaminopentane and melamine is 1-2:

1.

3. The method for preparing the ruthenium-nickel nano-alloy electrocatalytic material supported on a carbon-nitrogen support according to claim 1, characterized in that: The nickel salt mentioned in step (2) is nickel chloride, and the ruthenium salt is ruthenium chloride.

4. The method for preparing the ruthenium-nickel nano-alloy electrocatalytic material supported on a carbon-nitrogen support according to claim 1, characterized in that: The molar ratio of melamine added in step (1) to ruthenium salt added in step (2) is 2 to 4:1; the molar ratio of nickel salt added in step (2) to ruthenium salt is 1:1 to 5; The organic solvent mentioned in step (2) is N-methylpyrrolidone (NMP); the molar volume ratio between the sum of the ruthenium salt and the nickel salt and the organic solvent is 1 mmol: 60-80 mL.

5. The method for preparing the ruthenium-nickel nano-alloy electrocatalytic material supported on a carbon-nitrogen support according to claim 1, characterized in that: The settling time in step (3) is 3 to 6 hours.

6. The method for preparing the ruthenium-nickel nano-alloy electrocatalytic material supported on a carbon-nitrogen support according to claim 1, characterized in that: The powdered precursor described in step (5) is placed in the middle constant temperature zone of a single-temperature zone tube furnace, and then pyrolyzed under an argon atmosphere after a sealed cover is placed on the quartz boat of the tube furnace.

7. The method for preparing the ruthenium-nickel nano-alloy electrocatalytic material supported on a carbon-nitrogen support according to claim 1, characterized in that: In step (5), the flow rate of argon gas is controlled at 50-200 sccm. Before the pyrolysis reaction is started, the quartz tube of the tubular furnace is first purified by atmosphere treatment, and high-purity argon gas with a purity of ≥99.999% is introduced at a flow rate of 500-650 sccm for 10-30 min.

8. The method for preparing the ruthenium-nickel nano-alloy electrocatalytic material supported on a carbon-nitrogen support according to claim 1, characterized in that: The concentration of the hydrochloric acid solution in step (6) is 1-3 mol / L, and the soaking time is 24-36 h.

9. The application of the ruthenium-nickel alloy electrocatalytic material supported on a carbon-nitrogen support prepared according to claim 1 in the hydrogen production reaction by water electrolysis.

10. The application according to claim 9, characterized in that: In the application described, the ruthenium-nickel alloy electrocatalytic material supported on a carbon-nitrogen support prepared according to claim 1 is used as a hydrogen evolution electrocatalyst to construct a working electrode for the hydrogen evolution reaction of water electrolysis.

Images