Preparation method of nickel oxide loaded platinum hydrogen evolution catalyst

Abstract

The invention discloses a preparation method of a nickel oxide supported platinum hydrogen evolution catalyst, and belongs to the technical field of catalytic materials. The preparation method comprises the following main steps: weighing 0.2 g of nickel acetate tetrahydrate and 0.2 g of graphite, uniformly grinding, then transferring into a muffle furnace, calcining for 1-3 hours in an air atmosphere at 450-750 DEG C to obtain a precursor A, weighing 4-18 mg of the precursor A, putting into a certain amount of H2PtCl6 solution with the concentration of 0.2-1.5 mmol / L, carrying out ultrasonic treatment for 30-60 minutes, then heating for 5-10 hours in a reaction kettle at 160-200 DEG C to complete a hydrothermal reaction, cooling to room temperature, carrying out suction filtration, and drying, so as to obtain the nickel acetate / graphite composite material. The prepared catalyst is obtained. The prepared catalyst has the catalytic effect equivalent to that of commercial Pt / C, the usage amount of platinum is remarkably reduced compared with that of commercial Pt / C, and the catalyst has commercial application prospects.

Description

TECHNICAL FIELD

[0001] The application discloses a preparation method of a hydrogen evolution catalyst, in particular a preparation method of a hydrogen evolution catalyst with nickel oxide supporting platinum, and belongs to the technical field of energy materials. BACKGROUND

[0002] Hydrogen is considered as an ideal clean energy due to its high energy density and zero carbon emission. In industry, hydrogen is mainly prepared by the synthesis of fossil fuels such as natural gas reforming and coal gasification. With the rapid development of wind power and solar power, the price of electricity gradually decreases. Under this background, water electrolysis for hydrogen production has become the preferred method for preparing hydrogen due to its simple operation, high hydrogen purity and environmental protection. It is particularly important to prepare a high-efficiency hydrogen evolution reaction (HER) catalyst to reduce the consumption of electricity in the process of electrolytic hydrogen production. Therefore, developing a new type of hydrogen evolution catalyst and reducing the hydrogen evolution overpotential in the electrolysis process can greatly reduce the cell voltage in the process of electrolytic hydrogen production, and reduce the energy consumption and cost of electrolytic hydrogen production. Studies have shown that platinum is considered to be a good hydrogen evolution catalyst due to its lowest hydrogen evolution overpotential and fast HER kinetics, and it has been applied in commercial electrolytic hydrogen production to some extent. However, the reserves of platinum are limited and the price is high, which seriously hinders the wide application of platinum in the field of actual electrolytic hydrogen production. Therefore, developing platinum-based binary and ternary hydrogen evolution catalysts, or attaching platinum to carbon paper and other carriers, or preparing non-platinum catalysts has become a research hotspot in the field of HER catalysts. In other words, reducing the amount of platinum while maintaining the high activity of the hydrogen evolution catalyst is one of the effective ways to realize economic and efficient electrolytic hydrogen production.

[0003] Literature research shows that nickel has been partially applied in HER catalysts. For example, Yang Dongjiang et al. (CN119877000A) prepared a sulfur vacancy amorphous nickel sulfide hydrogen evolution catalyst by using nickel sulfide as a nickel source. The catalyst has the advantages of fast charge transfer, adjustable electronic structure, low HER electrochemical process energy barrier and excellent hydrogen evolution catalytic performance under large current density. Peng Xiang et al. (CN113652707A) prepared a layered nickel telluride hydrogen evolution catalyst by carrying out two hydrothermal reactions on nickel salt and tellurite. The above preparation methods generally have the disadvantages of complex preparation process and high preparation cost. Therefore, developing a new type of hydrogen evolution catalyst is still an important research content in the field of electrolytic hydrogen production. SUMMARY

[0004] The application aims to provide a preparation method of a hydrogen evolution catalyst with nickel oxide supporting platinum. The preparation process is simple, the amount of platinum used is low, and the prepared catalyst has good catalytic performance.

[0005] The concept of the present application is that, firstly, the nickel acetate tetrahydrate (Ni(CH3COO)2·4H2O) is fully ground with graphite, then the precursor is obtained by calcination at a certain high temperature, and then the obtained precursor is mixed with chloroplatinic acid solution, after hydrothermal reaction at a certain temperature for a period of time, the hydrogen evolution catalyst of nickel oxide supported platinum is obtained.

[0006] Specifically, the present application comprises the following steps: (1) Material preparation Materials needed: nickel acetate tetrahydrate (Ni(CH3COO)2·4H2O), chloroplatinic acid hexahydrate (H2PtCl6·6H2O), graphite; Materials needed for hydrogen evolution catalyst performance test: glassy carbon electrode, graphite rod, Hg / HgO reference electrode, 1 mol L-1 KOH solution; (2) Catalyst preparation First step: preparation of chloroplatinic acid solution Weigh 0.1~0.4 g H2PtCl6·6H2O into a beaker, add distilled water to constant volume and transfer to a 500 mL volumetric flask to obtain a chloroplatinic acid solution; Second step: high temperature calcination Put 0.05~0.50 g of nickel acetate tetrahydrate and 0.05~0.50 g of graphite together into a mortar and grind thoroughly for 5~12 min, then transfer to a crucible and calcine in a muffle furnace at 450~750℃ in air for 1~3 h to obtain precursor A; Preferred conditions: the mass of nickel acetate tetrahydrate and graphite is both ~0.2 g.

[0007] Preferred conditions: the calcination temperature in air in the muffle furnace is 550℃, and the time is 1 h.

[0008] Third step: hydrothermal reaction Weigh 4~18 mg of precursor A into a 10 mL centrifuge tube, add 5~15 mL of chloroplatinic acid solution with a concentration of 0.2~1.5 mmol L-1, ultrasonic for 30~60 min to make it fully mixed to form a suspension, then transfer the obtained suspension to a high-pressure reaction kettle, seal, heat at 160~200℃ for 5~10 h to complete the hydrothermal reaction, cool to room temperature, then perform suction filtration, dry the obtained black filter residue at 80℃ in air for 6 h to obtain black powder, which is the hydrogen evolution catalyst of nickel oxide supported platinum, denoted as Pt / NiO; Preferred conditions: the concentration of chloroplatinic acid is 0.98 mmol L-1.

[0009] Preferred conditions: the temperature of the hydrothermal reaction is 175℃.

[0010] Preferably, the time of the hydrothermal reaction is 10 h.

[0011] The components of the prepared catalyst are elemental platinum, NiO and graphite.

[0012] (3) Preparation of working electrode and test of hydrogen evolution catalytic performance of the prepared catalyst Take 2 mg Pt / NiO and dissolve in 0.5 mL Nafion solution, and obtain a suspension after ultrasonic treatment for 30 min. Then, take 10 μL of the suspension and drop it on a glassy carbon electrode using a pipette, and naturally dry it to prepare a glassy carbon electrode coated with a catalyst. Then, use this electrode as a working electrode, a graphite rod as a counter electrode, Hg / HgO as a reference electrode, and 1 mol L-1 KOH as an electrolyte to construct a classic three-electrode system, and complete the test of hydrogen evolution catalytic performance of the catalyst in a CHI 660B electrochemical workstation. When performing linear sweep voltammetry (LSV), the scanning speed is set to 5 mV s-1, and the potential interval is set to 0 V to -1.15 V to obtain the LSV curve of the hydrogen evolution reaction. Then, select the voltage corresponding to the current density of 10 mA cm-2 in the LSV curve as the center, and the voltage range of ± 50 mV from the center as the selected voltage range, and the current in the LSV curve corresponding to the selected voltage as the selected current, and draw the Tafel slope graph. According to the relationship between the measured voltage and the voltage of the relative reversible hydrogen electrode, i.e., voltage reversible hydrogen electrode = voltage measured value + 0.0592 pH + 0.098 V, draw the final LSV and Tafel slope graph using the voltage of the relative reversible hydrogen electrode. The chronoamperometry (CA) test curve is a curve of the relationship between time and current recorded at the voltage (vs. Hg / HgO) corresponding to the current density of 10 mA cm-2 in the LSV curve.

[0013] The application prepares a hydrogen evolution catalyst of nickel oxide loaded with platinum through a two-step method of high-temperature calcination and hydrothermal reaction. The Tafel slope of the catalyst is 41.3 mV dec-1 when the current density of the hydrogen evolution reaction is 10 mA cm-2, which is lower than 49.5 mV dec-1 of a commercial platinum-carbon electrode (Pt / C). In the CA test, when the applied voltage is all -0.97 V (relative to the reversible hydrogen electrode (RHE)), the HER current density on the catalyst is 7.6 mA cm-2 after 10 hours, which is obviously higher than 5.5 mA cm-2 of the commercial platinum-carbon electrode (Pt / C). Meanwhile, the test shows that the mass percentage of platinum in the catalyst is 14.2%, which is much lower than the mass percentage of platinum (20%) in the commercial platinum-carbon electrode (Pt / C).

[0014] The application has the advantages that the preparation process is simple and the cost is low. The catalyst prepared by the application has excellent HER catalytic performance and low platinum content, and has commercial application value. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is an XRD graph of the catalyst Pt / NiO.

[0016] Figure 2 It is an EDS graph of the catalyst Pt / NiO.

[0017] Figure 3 It is an LSV curve graph of the hydrogen evolution reaction (HER) of the catalyst Pt / NiO and the commercial platinum-carbon (Pt / C) in 1 mol L-1 KOH solution.

[0018] Figure 4 It is a Tafel slope graph of the catalyst Pt / NiO and the commercial Pt / C.

[0019] Figure 5 It is a CA test graph of the catalyst Pt / NiO and the commercial Pt / C. DETAILED DESCRIPTION

[0020] The following examples are used to illustrate the application. Example 1

[0021] Preparation of the hydrogen evolution catalyst of nickel oxide loaded with platinum 0.25 g of hexahydrated chloroplatinic acid (H2PtCl6·6H2O) is weighed by an electronic balance and put into a beaker, diluted with double-distilled water and made up to 500 mL in a volumetric flask to prepare a chloroplatinic acid solution with a concentration of 0.98 mmol L-1.

[0022] Take 0.20 g of nickel acetate tetrahydrate and 0.20 g of graphite together into a mortar and grind for 10 minutes, then transfer to a crucible and calcine in a muffle furnace at 550°C for 1 h under air atmosphere to obtain precursor A. Next, take 10 mg of precursor A into a 10 mL centrifuge tube, then add 10 mL of chloroplatinic acid solution with a concentration of 0.98 mmol L-1, and ultrasonicate for 60 min to form a suspension. Then, transfer the obtained suspension into a high-pressure reactor, seal it well, and heat at 175°C for 10 h to complete the hydrothermal reaction. After cooling to room temperature, perform suction filtration, and dry the obtained black filter residue at 80°C in air atmosphere for 6 h to obtain a black powder, thereby obtaining a hydrogen evolution catalyst Pt / NiO with platinum supported on nickel oxide.

[0023] Hydrogen evolution performance test of the catalyst The hydrogen evolution performance of the prepared catalyst was tested as follows: take 2 mg of the prepared catalyst Pt / NiO and dissolve it in 0.5 mL of Nafion solution, ultrasonicate for 30 min to obtain a suspension, then use a pipette to take 10 μL of the suspension and drop it onto a glassy carbon electrode, and naturally air dry to prepare a glassy carbon electrode coated with the catalyst. Take the electrode as the working electrode, a graphite rod as the counter electrode, Hg / HgO as the reference electrode, and 1 mol L-1 KOH as the electrolyte to construct a classic three-electrode system, and complete the test of the hydrogen evolution performance of the prepared catalyst on a CHI 660B electrochemical workstation. When performing linear sweep voltammetry (LSV), the scanning speed is set to 5 mV s-1, and the potential interval is set to 0 V to -1.15 V. In order to compare the hydrogen evolution performance of the catalyst with that of a commercial Pt / C catalyst, the commercial Pt / C catalyst was also tested under the same conditions. The results are shown in Figure 3 After that, select the voltage corresponding to the current density of 10 mA cm-2 in the LSV curve as the center (V10), take the voltage range of V10±50 mV as the selected voltage range, take the corresponding current as the selected current, and draw the Tafel slope graph. Note that in order to compare with the test results usually reported, when drawing the LSV and Tafel slope graphs, the direct test electrode potential value (measured electrode potential value) needs to be converted into the electrode potential relative to the reversible hydrogen electrode (electrode potential reversible hydrogen electrode) using the following relationship: electrode potential reversible hydrogen electrode = measured electrode potential value + 0.0592 pH + 0.098 V. Finally, draw the LSV and Tafel slope graphs, as shown in Figure 3 and 4 .

[0024] ReferenceFigure 1 , Figure 1 XRD patterns of catalyst Pt / NiO and precursor A, in which the standard cards of NiO, metallic Pt and graphite C are also given. Figure 1 The first sharp diffraction peak in the XRD pattern of precursor A is located at about 26.6°, which is attributed to the typical (002) crystal plane of graphite C (JCPDS, NO. 25-284), indicating that graphite exists as the main crystal material in precursor A and the prepared catalyst Pt / NiO. In the XRD pattern of precursor A, the diffraction peaks appearing at 37.3°, 43.4°, 63.0°, 75.6° and 79.6° correspond to the (111), (200), (220), (311) and (222) crystal planes of cubic system NiO (JCPDS, NO. 75-197), respectively, indicating that nickel acetate has been completely converted into NiO after calcination. In the XRD pattern of the prepared catalyst Pt / NiO, in addition to the diffraction peaks of graphite and NiO appearing in precursor A, the characteristic diffraction peaks of elemental platinum Pt (JCPDS, NO. 4-802) also appear, i.e. the diffraction peaks appearing at 39.8°, 46.3°, 67.5° and 81.3° correspond to the (111), (200), (220) and (311) crystal planes of platinum (Pt), respectively, indicating that chloroplatinic acid has been converted into elemental platinum after the hydrothermal reaction with graphite and other substances. According to the above XRD test results, it can be seen that graphite, NiO and elemental Pt are the main crystal materials of the prepared catalyst. At the same time, it can also be seen that graphite as the starting raw material has not undergone chemical changes before and after preparation, nickel acetate is converted into NiO after calcination, and chloroplatinic acid is converted into elemental platinum after the hydrothermal process, finally forming a new type of composite material with graphite as the main component and platinum supported by NiO. According to the literature, the use of calcination and hydrothermal methods to prepare hydrogen evolution catalysts containing the above-mentioned substances has not been reported.

[0025] Reference Example 1 Figure 2 , Figure 2 EDS pattern of catalyst Pt / NiO. The peaks of C, O, Ni and Pt four elements are clearly visible. Through EDS test, it can be known that the mass percentage contents of C, O, Ni and Pt elements in the prepared material are 77.21%, 6.33%, 2.28% and 14.19%, respectively. Compared with the mass percentage content of Pt element 20% in commercial Pt / C catalyst, it is shown that the amount of noble metal Pt in this catalyst is significantly reduced.

[0026] Reference Example 1 Figure 3 , Figure 3Linear sweep voltammetry (LSV) curves of the catalysts Pt / NiO and commercial Pt / C were tested in 1 mol L-1 KOH solution at a scan rate of 5 mV s-1. It can be seen that the onset potential (vs. RHE) of the HER of the prepared catalyst Pt / NiO and the commercial Pt / C are both close to 0 V. When the current density reaches 10 mA cm-2, the overpotential of the catalyst Pt / NiO and the commercial Pt / C are 39.56 mV and 37.85 mV, respectively, and the difference between them is not large. Therefore, under the condition of low current density, the HER electrocatalytic performance of the prepared catalyst Pt / NiO is equivalent to that of the commercial Pt / C catalyst.

[0027] Referring to Figure 4 , Figure 4 Tafel slope plots of the tested electrodes. The current density and the corresponding potential value used in the plots are taken from the LSV curves in Figure 3 . For the catalyst Pt / NiO, the potential value corresponding to 10 mA cm-2 is about 40 mV, and therefore the potential range (vs. RHE) used for drawing the Tafel curve is -10 mV to 90 mV. For the commercial Pt / C, the potential value corresponding to 10 mA cm-2 is about 38 mV, and therefore the potential range (vs. RHE) used for drawing the Tafel curve is -12 mV to 88 mV. The potential value and the current density used for drawing the Tafel slope have a one-to-one correspondence. It can be seen from Figure 4 that the Tafel curve slope values of the prepared catalyst Pt / NiO and the commercial Pt / C are about 41.3 and 49.5 mV dec-1, respectively. This indicates that the prepared catalyst Pt / NiO has a faster hydrogen evolution reaction (HER) kinetics than the commercial Pt / C.

[0028] Referring to Figure 5 , Figure 5 Chronoamperometric curves of the catalyst Pt / NiO and the commercial Pt / C at the potential value (vs. Hg / HgO) corresponding to the current density of 10 mA cm-2, i.e. -0.97 V (vs. Hg / HgO). After polarization for 10 hours, the hydrogen evolution current density on the Pt / NiO decreases from 15.70 to 7.81 mA cm-2, and the hydrogen evolution current density on the commercial Pt / C decreases from 7.35 to 5.60 mA cm-2. That is, the catalyst Pt / NiO has a higher current density throughout the test time, which indicates that the prepared catalyst has excellent HER catalytic performance. Example 2

[0029] Preparation of a hydrogen evolution catalyst of platinum supported on nickel oxide Take 0.10 g of chloroplatinic acid hexahydrate (H2PtCl6·6H2O) with an electronic balance and put it into a beaker, dilute it with double-distilled water and make up to 500 mL volumetric flask, i.e. prepare a 0.39 mmol L-1 chloroplatinic acid solution.

[0030] Take 0.05 g of nickel acetate tetrahydrate and 0.10 g of graphite together with an electronic balance and put them into a mortar and grind them for 5 minutes, then transfer them to a crucible and calcine them in a muffle furnace at 450℃ in air for 3 h to obtain precursor A. Next, take 6 mg of precursor A into a 10 mL centrifuge tube, then add 6 mL of 0.39 mmol L-1 chloroplatinic acid solution, and ultrasonicate for 50 min to make them fully mixed to form a suspension. Then, transfer the obtained suspension into a high-pressure reaction kettle, seal it well, and heat it at 160℃ for 5 h to complete the hydrothermal reaction. After cooling to room temperature, perform suction filtration, and dry the obtained black filter residue at 80℃ in air for 6 h to obtain a black powder, i.e. obtain the final hydrogen evolution catalyst Pt / NiO with platinum supported on nickel oxide.

[0031] Hydrogen evolution performance test of the catalyst The hydrogen evolution performance test of the catalyst was performed on a CHI 660B electrochemical workstation according to the operating method of Example 1. The results showed that when the current density reached 10 mA cm-2, the overpotential required for the hydrogen evolution reaction of the prepared catalyst was 40.32 mV, and the overpotential required for the hydrogen evolution reaction of commercial Pt / C was 37.32 mV; the Tafel slope of the hydrogen evolution reaction of the catalyst was about 44.1 mV dec-1, and the Tafel slope of Pt / C was about 50.1 mV dec-1. In the CA test, after 10 hours of polarization, the hydrogen evolution current density on the catalyst Pt / NiO and commercial Pt / C remained at 9.12 and 5.78 mA cm-2, respectively. The above hydrogen evolution performance test results showed that the prepared catalyst had excellent HER catalytic performance. Example 3

[0032] Preparation of hydrogen evolution catalyst with platinum supported on nickel oxide Take 0.15 g of chloroplatinic acid hexahydrate (H2PtCl6·6H2O) with an electronic balance and put it into a beaker, dilute it with double-distilled water and make up to 500 mL volumetric flask, i.e. prepare a 0.58 mmol L-1 chloroplatinic acid solution.

[0033] Take 0.10 g of nickel acetate tetrahydrate and 0.12 g of graphite together into a mortar and grind for 12 minutes, then transfer to a crucible and calcine in a muffle furnace at 650°C in air for 1 h to obtain precursor A. Next, take 10 mg of precursor A into a 10 mL centrifuge tube, then add 6 mL of chloroplatinic acid solution with a concentration of 0.58 mmol L-1, and ultrasonically mix for 45 min to form a suspension. Then, the obtained suspension is transferred to a high-pressure reaction kettle, and after sealing, hydrothermal reaction is completed at 185°C for 7 h. After cooling to room temperature, filtration is performed, and the obtained black filter residue is dried at 80°C in air for 6 h to obtain a black powder, which is the final hydrogen evolution catalyst Pt / NiO loaded with platinum.

[0034] Hydrogen evolution performance test of the catalyst The hydrogen evolution performance test of the catalyst was carried out on a CHI 660B electrochemical workstation according to the operation method of Example 1. The results show that when the current density reaches 10 mA cm-2, the overpotential required for the hydrogen evolution reaction of the prepared catalyst is 38.77 mV, and the overpotential required for the commercial Pt / C is 37.45 mV; the Tafel slope of the hydrogen evolution reaction of the catalyst is about 40.7 mV dec-1, and the Tafel slope of Pt / C is about 48.0 mV dec-1. In the CA test, after 10 hours of polarization, the hydrogen evolution current density on the catalyst Pt / NiO and the commercial Pt / C remained at 8.24 and 5.09 mA cm-2, respectively. The above hydrogen evolution performance test results show that the prepared catalyst has excellent HER catalytic performance. Example 4

[0035] Preparation of hydrogen evolution catalyst of platinum loaded on nickel oxide Take 0.30 g of chloroplatinic acid hexahydrate (H2PtCl6·6H2O) into a beaker, dilute with double-distilled water, and make up to a 500 mL volumetric flask to prepare a 1.16 mmol L-1 chloroplatinic acid solution.

[0036] Take 0.08 g of nickel acetate tetrahydrate and 0.20 g of graphite together into a mortar and grind for 6 minutes, then transfer to a crucible and calcine in a muffle furnace at 500°C in air for 2 h to obtain precursor A. Next, take 12 mg of precursor A into a 10 mL centrifuge tube, then add 15 mL of a chloroplatinic acid solution with a concentration of 1.16 mmol L-1, and ultrasonically mix for 40 min to form a suspension. Then, the obtained suspension is transferred to a high-pressure reaction kettle, and after sealing, hydrothermal reaction is completed at 190°C for 7 h. After cooling to room temperature, filtration is performed, and the obtained black filter residue is dried at 80°C in air for 6 h to obtain a black powder, which is the final hydrogen evolution catalyst Pt / NiO loaded with platinum.

[0037] Hydrogen evolution performance test of the catalyst The hydrogen evolution performance test of the catalyst was performed on a CHI 660B electrochemical workstation according to the operation method of Example 1. The results showed that when the current density reached 10 mA cm-2, the overpotential required for the hydrogen evolution reaction of the prepared catalyst was 37.54 mV, and the overpotential required for the hydrogen evolution reaction of commercial Pt / C was 36.33 mV; the Tafel slope of the hydrogen evolution reaction of the catalyst was about 45.3 mV dec-1, and the Tafel slope of Pt / C was about 48.2 mV dec-1. After 10 hours of polarization in the CA test, the hydrogen evolution current density on the catalyst Pt / NiO and commercial Pt / C was maintained at 8.96 and 6.04 mA cm-2, respectively. The above hydrogen evolution performance test results showed that the prepared catalyst had excellent HER catalytic performance. Example 5

[0038] Preparation of hydrogen evolution catalyst of platinum loaded on nickel oxide Take 0.35 g of chloroplatinic acid hexahydrate (H2PtCl6·6H2O) into a beaker, dilute with double-distilled water, and make up to a 500 mL volumetric flask to prepare a 1.35 mmol L-1 chloroplatinic acid solution.

[0039] Take 0.25 g of nickel acetate tetrahydrate and 0.15 g of graphite together into a mortar and grind for 8 minutes, then transfer to a crucible and calcine in a muffle furnace at 450°C in air for 1 h to obtain precursor A. Next, take 7 mg of precursor A into a 10 mL centrifuge tube, then add 5 mL of chloroplatinic acid solution with a concentration of 1.35 mmol L-1, and ultrasonic for 60 min to form a suspension. Then, the obtained suspension is transferred to a high-pressure reaction kettle, and after sealing, the hydrothermal reaction is completed at 195°C for 8 h. After cooling to room temperature, filtration is performed, and the black filter residue is dried at 80°C in air for 6 h to obtain a black powder, which is the final hydrogen evolution catalyst Pt / NiO loaded with platinum on nickel oxide.

[0040] Hydrogen evolution performance test of the catalyst The hydrogen evolution performance test of the catalyst was carried out on a CHI 660B electrochemical workstation according to the operation method of Example 1. The results show that when the current density reaches 10 mA cm-2, the overpotential required for the hydrogen evolution reaction of the prepared catalyst is 41.96 mV, and the overpotential required for the hydrogen evolution reaction of commercial Pt / C is 38.33 mV; the Tafel slope of the hydrogen evolution reaction of the catalyst is about 43.9 mV dec-1, and the Tafel slope of Pt / C is about 49.2 mV dec-1. After 10 hours of polarization in CA test, the hydrogen evolution current density on the catalyst Pt / NiO and commercial Pt / C is maintained at 6.92 and 5.11 mA cm-2, respectively. The above hydrogen evolution performance test results show that the prepared catalyst has excellent HER catalytic performance. Example 6

[0041] Preparation of hydrogen evolution catalyst of platinum loaded on nickel oxide Take 0.28 g of chloroplatinic acid hexahydrate (H2PtCl6·6H2O) into a beaker, dilute with double-distilled water, and make up to 500 mL in a volumetric flask to prepare a chloroplatinic acid solution with a concentration of 1.08 mmol L-1.

[0042] Take 0.36 g of nickel acetate tetrahydrate and 0.45 g of graphite together into a mortar and grind for 11 minutes, then transfer to a crucible and calcine in a muffle furnace at 560°C in air for 2 h to obtain precursor A. Next, take 15 mg of precursor A into a 10 mL centrifuge tube, then add 12 mL of chloroplatinic acid solution with a concentration of 1.08 mmol L-1, and ultrasonic for 50 min to form a suspension. Then, the obtained suspension is transferred to a high-pressure reactor, and after sealing, hydrothermal reaction is completed at 165°C for 5 h. After cooling to room temperature, filtration is performed, and the obtained black residue is dried at 80°C in air for 6 h to obtain a black powder, which is the final hydrogen evolution catalyst Pt / NiO.

[0043] Hydrogen evolution performance test of the catalyst The hydrogen evolution performance test of the catalyst was carried out on a CHI 660B electrochemical workstation according to the operation method of Example 1. The results show that when the current density reaches 10 mA cm-2, the overpotential required for the prepared catalyst to undergo hydrogen evolution reaction is 40.30 mV, and the overpotential required for commercial Pt / C is 36.19 mV; the Tafel slope of the catalyst to undergo hydrogen evolution reaction is about 48.7 mV dec-1, and the Tafel slope of Pt / C is about 49.3 mV dec-1. After 10 hours of polarization in CA test, the hydrogen evolution current density on the catalyst Pt / NiO and commercial Pt / C is 7.11 and 6.07 mA cm-2, respectively. The above hydrogen evolution performance test results show that the prepared catalyst has excellent HER catalytic performance.

Claims

1. A method for preparing a nickel oxide-supported platinum hydrogen evolution catalyst, characterized in that... Includes the following steps: (1) Material preparation Materials required: Nickel acetate tetrahydrate Ni(CH3COO)2·4H2O, chloroplatinic acid hexahydrate H2PtCl6·6H2O, graphite; Materials required for hydrogen evolution catalyst performance testing: glassy carbon electrode, graphite rod, Hg / HgO reference electrode, 1 mol L... -1 KOH solution; (2) Catalyst preparation Step 1: Preparation of chloroplatinic acid solution Weigh 0.1~0.4 g of H2PtCl6·6H2O into a beaker, add distilled water to make up to volume and transfer to a 500 mL volumetric flask to obtain chloroplatinic acid solution; Step 2: High-temperature calcination 0.05-0.50 g of nickel acetate tetrahydrate and 0.05-0.50 g of graphite were placed together in a mortar and ground thoroughly for 5-12 minutes. Then, the mixture was transferred to a crucible and calcined in an air atmosphere at 450-750℃ for 1-3 hours to obtain precursor A. Step 3: Hydrothermal reaction Weigh 4–18 mg of precursor A into a 10 mL centrifuge tube, and add 5–15 mL of a 0.2–1.5 mmol / L solution. -1 The chloroplatinic acid solution was sonicated for 30-60 min to form a suspension. The suspension was then transferred to a high-pressure reactor, sealed, and heated at 160-200℃ for 5-10 h to complete the hydrothermal reaction. After cooling to room temperature, the mixture was filtered, and the resulting black filter residue was dried at 80℃ in air for 6 h to obtain a black powder, which is the nickel oxide-supported platinum hydrogen evolution catalyst, denoted as Pt / NiO.

2. The preparation method according to claim 1, characterized in that, In the preparation of the catalyst, the mass of both nickel acetate tetrahydrate and graphite was 0.20 g.

3. The preparation method according to claim 1, characterized in that, The calcination temperature in the muffle furnace under air atmosphere was 550℃ for 1 hour.

4. The preparation method according to claim 1, characterized in that, The amount of precursor used in the hydrothermal reaction is 4-18 mg, and the concentration of chloroplatinic acid is 0.98 mmol / L. -1 .

5. The preparation method according to claim 1, characterized in that, The hydrothermal reaction temperature is 175℃.

6. The preparation method according to claim 1, characterized in that, The hydrothermal reaction time was 10 h.

7. The preparation method according to claim 1, characterized in that, The catalyst was prepared from elemental platinum, NiO and graphite.

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