Ru / La-niCoP / BM catalyst, preparation method and application thereof

Abstract

The application provides a Ru / La-NiCoP / BM catalyst and a preparation method and application thereof, and relates to the technical field of hydrogen production by water electrolysis. The preparation method can efficiently and stably prepare the Ru / La-NiCoP / BM catalyst through a preparation process of 'hydrothermal treatment + electrodeposition treatment + low-temperature phosphating treatment'. The price of raw materials used for preparation is much lower than that of a Pt-based noble metal catalyst, the preparation cost is relatively low, large-scale production is easy, and great innovation is brought to hydrogen production by water electrolysis, large-scale energy conversion and storage by using renewable energy. The catalyst has a 3D interconnected nanosheet structure, ensures uniform distribution of Ru therein, effectively improves the electrochemical active surface area (ECSA) of the Ru / La-NiCoP / BM catalyst, and can accelerate electron transmission and reaction kinetics in the catalytic process, and has excellent HER catalytic activity and stability.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of hydrogen production by electrolysis of water, in particular to a Ru / La-NiCoP / BM catalyst and a preparation method and application thereof. BACKGROUND

[0002] Hydrogen production by water electrolysis (HER) is considered a sustainable option for large-scale energy conversion and storage using renewable energy sources such as solar, wind and hydroelectric power. However, the slow kinetics of HER severely limits its widespread application. Currently, Pt-based noble metal catalysts are still the most optimal electrolytic water catalysts, but the characteristics of high price and low reserves greatly limit their large-scale application. Therefore, developing high-efficiency, low-cost HER catalysts is the key to solving the current development bottleneck of electrolytic water.

[0003] Non-metallic catalysts have attracted more and more attention due to their advantages of abundant raw material sources and low prices. However, existing non-metallic catalysts have limited HER performance and are difficult to exhibit competitive performance in electrolytic water, and the hydrogen evolution efficiency is low, so that the entire electrolysis system cannot maintain long-term operation at high current density. SUMMARY

[0004] The main purpose of the present application is to provide a Ru / La-NiCoP / BM catalyst and a preparation method and application thereof, aiming to solve the problems of high cost, poor stability and difficulty in meeting the demand of industrial electrolytic tank (usually > 5kA / m²) of existing hydrogen production by electrolysis of water catalyst.

[0005] To achieve the above purpose, the present application provides a Ru / La-NiCoP / BM catalyst, which is a 3D interconnected nanosheet structure; the 3D interconnected nanosheet structure is a three-dimensional network structure formed by mutual connection of a plurality of nanoscale thin sheets; Ru is uniformly dispersed in the Ru / La-NiCoP / BM catalyst, and the doping ratio of Ru is 0.1-1%.

[0006] The present application also provides a preparation method of the Ru / La-NiCoP / BM catalyst, comprising the following steps:

[0007] A reaction mixture is provided; the reaction mixture comprises nickel salt, cobalt salt, lanthanum salt, fluorine-containing ammonium salt, urea and water; in the reaction mixture, the molar ratio of the nickel salt, the cobalt salt, the lanthanum salt, the fluorine-containing ammonium salt and the urea is (0.05-0.2):(0.1-0.25):(0.01-0.03):2:1.

[0008] Immersion of a substrate into the reaction mixture and hydrothermal treatment to obtain a La-NiCo-LDH / BM precursor; the substrate is one of foamed nickel, foamed nickel-iron, foamed copper, nickel mesh and nickel felt; the temperature of the hydrothermal treatment is 100-180 DEG C.

[0009] Construction of a three-electrode system with the La-NiCo-LDH / BM precursor as a working electrode and electro-deposition treatment to obtain Ru / La-NiCo-LDH / BM; the electrolyte of the electro-deposition treatment contains 200-800 µM RuCl3.

[0010] The Ru / La-NiCo-LDH / BM and a phosphorus source are placed in the downstream and upstream of a tube furnace respectively, and low-temperature phosphorization treatment is carried out at 250-400 DEG C to obtain a Ru / La-NiCoP / BM catalyst.

[0011] Further, the nickel salt is a nickel-containing nitrate, a nickel-containing sulfate or a nickel-containing chloride; the cobalt salt is a cobalt-containing nitrate, a cobalt-containing sulfate or a cobalt-containing chloride; and the lanthanum salt is a lanthanum-containing nitrate, a lanthanum-containing sulfate or a lanthanum-containing chloride.

[0012] Further, the duration of the hydrothermal treatment is 4-8 h.

[0013] Further, the three-electrode system further comprises a graphite rod as a counter electrode and Hg / HgO as a reference electrode.

[0014] Further, the deposition potential window range of the electro-deposition treatment is (0-0.2) V to (-0.6--0.8) V (vs. RHE); and the cycle period of the electro-deposition treatment is 9-11 cycles.

[0015] Further, in the electrolyte, the concentration of the KOH solution is 0.5-1.5 M; and the concentration of the RuCl3 is 200-800 µM.

[0016] Further, the heating rate of the low-temperature phosphorization treatment is 2-5 DEG C·min -1 ; and the duration of the low-temperature phosphorization treatment is 1-3 h.

[0017] The application further provides a Ru / La-NiCoP / BM catalyst as described above or prepared by the preparation method as described above in the application of water electrolysis to produce hydrogen; the Ru / La-NiCoP / BM catalyst is used as a working electrode in an alkaline electrolytic cell for electrolysis treatment to obtain H2.

[0018] Further, the working current density of the working electrode is 1-10 kA / m².

[0019] The beneficial effects achieved by the present application are as follows:

[0020] The preparation method of the Ru / La-NiCoP / BM catalyst provided by the present application can efficiently and stably prepare the Ru / La-NiCoP / BM catalyst through the preparation process of "hydrothermal treatment + electrodeposition treatment + low-temperature phosphating treatment". The price of the raw material used for preparing the Ru / La-NiCoP / BM catalyst is much lower than that of a Pt-based noble metal catalyst, the preparation cost is relatively low, and the catalyst is easy to mass-produce, which brings great innovation to the electrolytic water hydrogen production, large-scale energy conversion and storage using renewable energy.

[0021] The Ru / La-NiCoP / BM catalyst provided by the present application has a 3D interconnected nanosheet structure, which ensures the uniform distribution of Ru therein, effectively improves the electrochemical active surface area (ECSA) of the Ru / La-NiCoP / BM catalyst, and can accelerate the electron transmission and reaction kinetics in the catalytic process, and has excellent HER catalytic activity and stability.

[0022] Further, the Ru / La-NiCoP / BM catalyst provided by the present application introduces a rare earth element La for doping, the introduction of La not only adjusts the geometric configuration and electron arrangement of the NiCoP material, but also improves the conductivity of the catalyst. More importantly, the addition of La stabilizes the reaction intermediates in the HER process, thereby improving the stability of the catalyst and prolonging the service life of the catalyst.

[0023] In the present application, the electrodeposition strategy realizes the atomic-level uniform dispersion of Ru. Through the electrodeposition strategy, Ru can realize atomic-level uniform distribution in the La-NiCo-LDH / BM matrix, avoiding the common noble metal agglomeration problem in traditional synthesis methods. The uniform dispersion of Ru optimizes the electronic structure of the catalyst and improves its electrochemical activity.

[0024] In the present application, Ru doping can optimize the electronic structure and active site exposure. Ru doping causes lattice mismatch, optimizes the electronic structure of the catalyst, and exposes more active sites. This not only increases the catalytic activity of the catalyst, but also improves the electrochemical reaction rate.

[0025] The Ru / La-NiCoP / BM catalyst can be applied to the electrolytic water hydrogen production, can adapt to a wide range of working current density, can meet the demand of an industrial electrolytic cell with a current density of more than 5 kA / m², can effectively promote the catalytic process, can realize efficient and stable production of hydrogen, and has a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only represent some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor based on the drawings shown.

[0027] Figure 1 SEM image of the Ru / La-NiCoP / BM catalyst in Example 1 of the present application;

[0028] Figure 2 LSV comparison chart of the materials prepared in each example and comparative example in Analysis Example 1 of the present application;

[0029] Figure 3 Stability effect chart of the Ru / La-NiCoP / BM catalyst in Example 1 of Analysis Example 1 of the present application.

[0030] The implementation, functional features and advantages of the present application will be further described with reference to the accompanying drawings. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments only represent some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0032] It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present application are for describing specific specific embodiments, and are not intended to limit the protection scope of the present application.

[0033] Unless otherwise defined, all technical and scientific terms used in the present application are consistent with the understanding of the prior art by those skilled in the art and the description of the present application. Any method, equipment and material of the prior art similar or equivalent to the method, equipment and material described in the embodiments of the present application can be used to implement the present application. Those skilled in the art should know that as a description of the present application, without affecting the actual understanding of the technical solutions of the present application, “Potential (vs. RHE)” can be expressed as potential, “Current density (mA·cm -2 )” can be expressed as current density, and “Time (h)” can be expressed as test time.

[0034] When embodiments give numerical ranges, it is understood that unless the disclosure specifically states otherwise, each numerical range is a continuum, and each end point to each numerical range and any number in between is also strictly an option. Test methods not otherwise specified in the following examples were generally conducted in accordance with conventional conditions, or as suggested by the manufacturer. Materials or reagents needed in the following examples, if not otherwise specified, were obtained from vendors.

[0035] In order to solve the problems of high cost, poor stability and difficult to meet the demand of industrial electrolytic cell (usually >5kA / m²) of existing electrolytic water hydrogen catalyst, the application provides a Ru / La-NiCoP / BM catalyst, the Ru / La-NiCoP / BM catalyst is a 3D interconnected nanosheet structure; the 3D interconnected nanosheet structure is a three-dimensional network structure formed by mutual connection of a plurality of nanoscale thin sheets; Ru is uniformly dispersed in the Ru / La-NiCoP / BM catalyst, and the doping ratio of the Ru is 0.1-1%. Optionally, the thickness to width ratio of the nanoscale thin sheet is (1-5):(500-1500). Preferably, the thickness of the nanoscale thin sheet is 10-50nm, and the width of the nanoscale thin sheet is 5-15µm.

[0036] Specifically, the 3D interconnected nanosheet structure of the Ru / La-NiCoP / BM catalyst can significantly increase the surface area of the Ru / La-NiCoP / BM catalyst, thereby providing a larger contact area for the reactants, enhancing the catalytic reaction rate, and improving the adsorption capacity of the catalyst. The Ru element is uniformly deposited on the Ru / La-NiCoP / BM catalyst, ensuring its atomic dispersion, thereby avoiding the problem of noble metal agglomeration in traditional methods.

[0037] The Ru / La-NiCoP / BM catalyst provided by the application has a 3D interconnected nanosheet structure, ensuring uniform distribution of Ru therein; effectively improves the electrochemical active surface area (ECSA) of the Ru / La-NiCoP / BM catalyst, and can accelerate the electron transfer and reaction kinetics in the catalytic process, has excellent HER catalytic activity and stability.

[0038] The application further provides a preparation method of the Ru / La-NiCoP / BM catalyst, comprising the steps of:

[0039] The reaction mixture solution is provided, and the reaction mixture solution comprises a nickel salt, a cobalt salt, a lanthanum salt, a fluorine-containing ammonium salt, urea and water. In the reaction mixture solution, the molar ratio of the nickel salt, the cobalt salt, the lanthanum salt, the fluorine-containing ammonium salt and the urea is (0.05-0.2):(0.1-0.25):(0.01-0.03):2:1. Preferably, the fluorine-containing ammonium salt is NH4F. The substrate is immersed in the reaction mixture solution, and hydrothermal treatment is performed to obtain a La-NiCo-LDH / BM precursor; the substrate is one of foamed nickel, foamed nickel-iron, foamed copper, a nickel mesh and a nickel felt; the temperature of the hydrothermal treatment is 100-180°C.

[0040] It should be noted that "BM" in the La-NiCo-LDH / BM precursor refers to the doped substrate. "NF" refers to foamed nickel; La-NiCo-LDH / NF indicates that the substrate doped in the preparation process of the catalyst is foamed nickel.

[0041] Specifically, the rare earth element La is introduced by hydrothermal treatment, which not only adjusts the geometric configuration and electronic arrangement of the transition metal phosphide NiCoP material, but also helps to improve the electrical conductivity of the final product Ru / La-NiCoP / BM catalyst. More importantly, the addition of La stabilizes the reaction intermediates in the HER process, thereby improving the stability of the Ru / La-NiCoP / BM catalyst and prolonging the service life of the Ru / La-NiCoP / BM catalyst. Preferably, foamed nickel is used as the substrate, and the foamed nickel is sequentially cleaned in 3M HCl, acetone and ethanol by ultrasonic treatment for 30 minutes. Then, the cleaned foamed nickel is vacuum dried at 60°C for 12h for standby. In an optional embodiment, the vacuum-dried foamed nickel is immersed in the reaction mixture solution, and hydrothermal treatment is performed at 150°C. After the autoclave is naturally cooled to room temperature, ultrasonic cleaning is sequentially performed with distilled water and anhydrous ethanol, and then the La-NiCo-LDH / BM precursor is obtained by fully drying in a vacuum drying oven at 60°C.

[0042] The Ru / La-NiCo-LDH / BM is obtained by constructing a three-electrode system with the La-NiCo-LDH / BM precursor as a working electrode and performing electrodeposition treatment; the electrolyte for the electrodeposition treatment contains 200-800 µM RuCl3. Specifically, by the electrodeposition strategy, the Ru in 200-800 µM RuCl3 can be uniformly distributed at an atomic level in the La-NiCo-LDH / BM, avoiding the agglomeration problem of noble metals commonly seen in traditional synthesis methods. By the electrodeposition treatment, the Ru is uniformly dispersed, the electronic structure of the catalyst is optimized, and the electrochemical activity is improved. Moreover, the 3D interconnected nanosheet structure of the final product is laid. The uniformly doped Ru causes lattice mismatch, optimizes the electronic structure of the catalyst, and exposes more active sites; which helps to increase the catalytic activity of the final product Ru / La-NiCoP / BM catalyst and improve the electrochemical reaction rate.

[0043] The Ru / La-NiCo-LDH / BM and the phosphorus source are placed in the downstream and upstream of a tube furnace respectively, and low-temperature phosphorization treatment is performed at 250-400℃ to obtain the Ru / La-NiCoP / BM catalyst. Preferably, the phosphorus source is triphenylphosphine, sodium phosphite or sodium hypophosphite. Specifically, the Ru / La-NiCo-LDH / BM obtained by electrodeposition treatment and the phosphorus source can be placed in the downstream of the tube furnace, and the phosphorus source is placed in the upstream thereof, and the Ru / La-NiCoP / BM catalyst is obtained by phosphorization at 250-400℃ in a nitrogen atmosphere.

[0044] The preparation method of the Ru / La-NiCoP / BM catalyst provided by the application can efficiently and stably prepare the Ru / La-NiCoP / BM catalyst through the preparation process of "hydrothermal treatment + electrodeposition treatment + low-temperature phosphorization treatment". Moreover, the price of the raw materials used for preparing the Ru / La-NiCoP / BM catalyst is much lower than that of the Pt-based noble metal catalyst, the preparation cost is relatively low, and the catalyst is easy to mass-produce, which brings great innovation to the electrolytic water hydrogen production, large-scale energy conversion and storage using renewable energy.

[0045] Further, the nickel salt is a nickel-containing nitrate, a nickel-containing sulfate or a nickel-containing chloride salt; the cobalt salt is a cobalt-containing nitrate, a cobalt-containing sulfate or a cobalt-containing chloride salt; and the lanthanum salt is a lanthanum-containing nitrate, a lanthanum-containing sulfate or a lanthanum-containing chloride salt. Preferably, the nickel salt is Ni(NO3)2·6H2O; the cobalt salt is Co(NO3)2·6H2O; and the lanthanum salt is La(NO3)3·6H2O.

[0046] Further, the hydrothermal treatment is performed for 4-8 h.

[0047] Further, the three-electrode system further comprises a graphite rod as a counter electrode and a Hg / HgO as a reference electrode.

[0048] Further, the deposition potential window range of the electrodeposition treatment is (0~0.2) V to (-0.6~-0.8) V (vs. RHE); the cycle period of the electrodeposition treatment is 9~11 cycles. Preferably, the scanning rate of the electrodeposition treatment is 5 mV / s; the cycle period of the electrodeposition treatment is 10 cycles.

[0049] Further, in the electrolyte, the concentration of the KOH solution is 0.5~1.5 M; the concentration of the RuCl3 is 200~800 µM. Preferably, the concentration of the KOH solution is 1.0 M.

[0050] Further, the heating rate of the low-temperature phosphating treatment is 2~5℃·min -1 ; the time length of the low-temperature phosphating treatment is 2h. Specifically, in the low-temperature phosphating treatment, the tubular furnace is heated to 250~400℃ at a heating rate of 2~5℃·min -1 , and is kept for 1~3h to obtain the Ru / La-NiCoP / BM catalyst. Preferably, the keeping time length is 2h.

[0051] The application further provides a use of the Ru / La-NiCoP / BM catalyst or the Ru / La-NiCoP / BM catalyst prepared by the above preparation method in water electrolysis for hydrogen production. The Ru / La-NiCoP / BM catalyst is used as a working electrode in an alkaline electrolytic cell for electrolysis treatment to obtain H2.

[0052] Further, the working current density of the working electrode is 1~10kA / m². Optionally, the working current density of the working electrode is 1~5kA / m². Optionally, the working current density of the working electrode is 6~10kA / m². Optionally, the working current density of the working electrode is 8~10kA / m². Optionally, the working current density of the working electrode is 6~8kA / m².

[0053] The Ru / La-NiCoP / BM catalyst can be applied to water electrolysis for hydrogen production, can adapt to a wide range of working current densities, can meet the requirements of an industrial electrolytic cell with a working current density of more than 5kA / m², can effectively promote the catalytic process, can realize efficient and stable production of hydrogen, and has a wide application prospect.

[0054] In order to further understand the application, examples are provided as follows:

[0055] Example 1

[0056] (1) Foam nickel was used as a substrate, and was sequentially subjected to ultrasonic cleaning in 3 M HCl, acetone and ethanol for 30 min, and then the cleaned foam nickel was vacuum dried at 60℃ for 12 h.

[0057] (2) 0.6 mmol of Ni(NO3)2·6H2O, 1.2 mmol of Co(NO3)2·6H2O, 0.08 mmol of La(NO3)3·6H2O, 12 mmol of CO(NH2)2 and 6 mmol of NH4F were dissolved in 60 mL of deionized water, and the solution was stirred uniformly using a magnetic stirrer to obtain a reaction mixture; then the mixed solution was transferred to a 100 mL stainless steel autoclave lined with Teflon, and the foam nickel cleaned in step (1) was immersed in the reaction mixture, and kept at 150°C for 5 h. After the autoclave was naturally cooled to room temperature, it was ultrasonically cleaned with distilled water and anhydrous ethanol in turn, and then fully dried in a vacuum drying box at 60°C to obtain a La-NiCo-LDH / NF precursor.

[0058] (3) A three-electrode system was assembled with the La-NiCo-LDH / NF precursor as the working electrode, Hg / HgO and a graphite rod as the reference electrode and the counter electrode, respectively. The electrolyte was a 1M KOH solution containing 360 µM RuCl3, and cyclic voltammetry (CV) was used, from 0 to -0.6 V (vs. RHE), with a scan rate of 5 mV / s, and 10 cycles were performed. After electrodeposition treatment, the working electrode was rinsed with deionized water and dried in a vacuum to obtain Ru / La-NiCo-LDH / NF.

[0059] (4) 350 mg of triphenylphosphine and Ru / La-NiCo-LDH / NF produced in step (3) were placed upstream and downstream of a tube furnace, respectively, and then purged with nitrogen at a flow rate of 200 sccm for about 15 min, after which the tube furnace was heated to 300°C at a heating rate of 2°C·min -1 -1, under a flow rate of 50 sccm, and kept for 2 h. Finally, the substrate after low-temperature phosphating treatment was collected, i.e. Ru / La-NiCoP / NF catalyst (wherein the doping ratio of Ru was 0.36%).

[0060] Example 2

[0061] (1) Foam nickel was used as the substrate, and was sequentially cleaned in 3M HCl, acetone and ethanol by ultrasonic treatment for 30 min, and then the cleaned foam nickel was vacuum dried at 60°C for 12 h.

[0062] (2) 0.6 mmol of Ni(NO3)2·6H2O, 1.2 mmol of Co(NO3)2·6H2O, 0.08 mmol of La(NO3)3·6H2O, 12 mmol of CO(NH2)2 and 6 mmol of NH4F were dissolved in 60 mL of deionized water, and the solution was stirred uniformly using a magnetic stirrer to obtain a reaction mixture; then the mixed solution was transferred to a 100 mL stainless steel autoclave lined with Teflon, and the foam nickel cleaned in step (1) was immersed in the reaction mixture, which was kept at 100°C for 8 h, and after the autoclave was naturally cooled to room temperature, it was ultrasonically cleaned with distilled water and anhydrous ethanol in turn, and then fully dried in a vacuum drying box at 60°C to obtain a La-NiCo-LDH / NF precursor.

[0063] (3) A three-electrode system was assembled with the La-NiCo-LDH / NF precursor as the working electrode, Hg / HgO and a graphite rod as the reference electrode and the counter electrode, respectively. The electrolyte was a 1M KOH solution containing 200 µM RuCl3, and cyclic voltammetry (CV) was used, from 0.2 to -0.8 V (vs. RHE), with a scan rate of 5 mV / s, and 10 cycles were performed. After electrodeposition treatment, the working electrode was rinsed with deionized water and dried in a vacuum to obtain Ru / La-NiCo-LDH / NF.

[0064] (4) 350 mg of triphenylphosphine and Ru / La-NiCo-LDH / NF produced in step (3) were placed upstream and downstream of a tube furnace, respectively, and then purged with nitrogen at a flow rate of 200 sccm for about 15 min, after which the tube furnace was heated to 300°C at a heating rate of 2°C·min -1 -1 was obtained (wherein the doping ratio of Ru is 0.21%).

[0065] Example 3

[0066] (1) Foam nickel was used as the substrate and was sequentially cleaned in 3 M HCl, acetone and ethanol with a concentration of 3 M by ultrasonic treatment for 30 min, and then the cleaned foam nickel was vacuum dried at 60°C for 12 h.

[0067] (2) 0.6 mmol of Ni(NO3)2·6H2O, 1.2 mmol of Co(NO3)2·6H2O, 0.08 mmol of La(NO3)3·6H2O, 12 mmol of CO(NH2)2 and 6 mmol of NH4F were dissolved in 60 mL of deionized water, and the solution was stirred uniformly using a magnetic stirrer to obtain a reaction mixture; then the mixed solution was transferred to a 100 mL stainless steel autoclave lined with Teflon, and the foam nickel cleaned in step (1) was immersed in the reaction mixture, and kept at 180°C for 4 h; after the autoclave was naturally cooled to room temperature, it was ultrasonically cleaned with distilled water and anhydrous ethanol in turn, and then fully dried in a vacuum drying box at 60°C to obtain a La-NiCo-LDH / NF precursor.

[0068] (3) A three-electrode system was assembled with the La-NiCo-LDH / NF precursor as the working electrode, Hg / HgO and a graphite rod as the reference electrode and the counter electrode, respectively. The electrolyte was a 1M KOH solution containing 800 µM RuCl3, and cyclic voltammetry (CV) was used, from 0 to -0.6 V (vs. RHE), with a scan rate of 5 mV / s, and 10 cycles were performed. After electrodeposition treatment, the working electrode was rinsed with deionized water and dried in a vacuum to obtain Ru / La-NiCo-LDH / NF.

[0069] (4) 350 mg of triphenylphosphine and Ru / La-NiCo-LDH / NF produced in step (3) were placed upstream and downstream of a tube furnace, respectively, and then purged with nitrogen at a flow rate of 200 sccm for about 15 min, after which the tube furnace was heated to 300°C at a heating rate of 2°C·min -1 , under a flow rate of 50 sccm, and kept for 2 h, and finally the substrate after low-temperature phosphating treatment was collected, i.e. Ru / La-NiCoP / NF-2 catalyst (wherein the doping ratio of Ru is 0.65%).

[0070] Comparative Example 1

[0071] (1) Foam nickel was used as the substrate, and was sequentially cleaned in 3 M HCl, acetone and ethanol with a concentration of 3 M by ultrasonic treatment for 30 min, and then the cleaned foam nickel was vacuum dried at 60°C for 12 h.

[0072] (2) 0.6 mmol of Ni(NO3)2·6H2O, 1.2 mmol of Co(NO3)2·6H2O, 12 mmol of CO(NH2)2 and 6 mmol of NH4F were dissolved in 60 mL of deionized water, and the solution was stirred uniformly using a magnetic stirrer; then the mixed solution was transferred to a 100 mL stainless steel autoclave with a Teflon lining, and the foam nickel cleaned in step (1) was immersed in the reaction solution, which was kept at 150°C for 5 h. After the autoclave was naturally cooled to room temperature, it was ultrasonically cleaned with distilled water and anhydrous ethanol in turn, and then fully dried in a vacuum drying box at 60°C to obtain a NiCo-LDH / NF precursor.

[0073] (3) A three-electrode system was assembled with the NiCo-LDH / NF precursor as the working electrode, Hg / HgO and a graphite rod as the reference electrode and the counter electrode, respectively. The electrolyte was a 1 M KOH solution containing 360 μM RuCl3, and cyclic voltammetry (CV) was used, from 0 to -0.6 V (vs. RHE), at a scan rate of 5 mV / s, for 10 cycles. After electrodeposition treatment, the working electrode was rinsed with deionized water and dried in a vacuum to obtain a Ru-NiCo-LDH / NF.

[0074] (4) 350 mg of triphenylphosphine and the Ru-NiCo-LDH / NF produced in step (3) were placed upstream and downstream of a tube furnace, respectively, and then purged with nitrogen at a flow rate of 200 sccm for about 15 min, after which the tube furnace was heated to 300°C at a heating rate of 2°C·min -1 -1, under a flow rate of 50 sccm, and kept for 2 h. Finally, the substrate after phosphidation treatment was collected, i.e. a Ru-NiCoP / NF catalyst was obtained.

[0075] Comparative Example 2

[0076] (1) Foam nickel was used as the substrate, and was sequentially cleaned by ultrasonic treatment in 3 M HCl, acetone and ethanol, each for 30 min, and then the cleaned foam nickel was vacuum dried at 60°C for 12 h.

[0077] (2) 0.6 mmol of Ni(NO3)2·6H2O, 1.2 mmol of Co(NO3)2·6H2O, 0.08 mmol of La(NO3)3·6H2O, 12 mmol of CO(NH2)2 and 6 mmol of NH4F were dissolved in 60 mL of deionized water, and the solution was stirred uniformly using a magnetic stirrer; then the mixed solution was transferred to a 100 mL stainless steel autoclave with a Teflon lining, and the foam nickel cleaned in step (1) was immersed in the reaction solution, which was kept at 150°C for 5 h. After the autoclave was naturally cooled to room temperature, it was ultrasonically washed with distilled water and anhydrous ethanol in turn, and then fully dried in a vacuum drying box at 60°C to obtain a La-NiCo-LDH / NF precursor.

[0078] (3) 350 mg of triphenylphosphine and the La-NiCo-LDH / NF precursor produced in step (2) were placed upstream and downstream of the tube furnace respectively, and then purged with nitrogen at a flow rate of 200 sccm for about 15 min. The tube furnace was heated to 300°C at a heating rate of 2°C·min -1

[0079] Comparative Example 3

[0080] (1) The foam nickel was cleaned by ultrasonic treatment in 3 M HCl, acetone and ethanol in turn, each for 30 min, and then dried in a vacuum drying box at 60°C for 12 h.

[0081] (2) 0.6 mmol of Ni(NO3)2·6H2O, 1.2 mmol of Co(NO3)2·6H2O, 0.08 mmol of La(NO3)3·6H2O, 12 mmol of CO(NH2)2 and 6 mmol of NH4F were dissolved in 60 mL of deionized water, and the solution was stirred uniformly using a magnetic stirrer; then the mixed solution was transferred to a 100 mL stainless steel autoclave with a Teflon lining, and the foam nickel cleaned in step (1) was immersed in the reaction solution, which was kept at 150°C for 5 h. After the autoclave was naturally cooled to room temperature, it was ultrasonically washed with distilled water and anhydrous ethanol in turn, and then fully dried in a vacuum drying box at 60°C to obtain a La-NiCo-LDH / NF precursor.

[0082] ​(3) A three-electrode system was assembled with the La-NiCo-LDH / NF precursor as the working electrode, Hg / HgO and a graphite rod as the reference electrode and the counter electrode, respectively. The electrolyte was a 1M KOH solution containing 360μM RuCl3, and cyclic voltammetry (CV) was used from 0 to -0.6 V (vs. RHE) at a scan rate of 5mV / s for 10 cycles. After electrodeposition, the working electrode was rinsed with deionized water and dried in vacuum to obtain Ru / La-NiCo-LDH / NF.

[0083] (4) The Ru / La-NiCo-LDH / NF produced in step (3) was placed in a tube furnace, then purged with nitrogen at a flow rate of 200sccm for about 15min, and then heated to 300℃ at a heating rate of 2℃·min -1 -1 under a flow rate of 50sccm, and kept for 2h. Finally, the Ru / La-NiCo / NF catalyst was obtained.

[0084] Comparative Example 4

[0085] (1) The foam nickel was cleaned in 3M HCl, acetone and ethanol with ultrasonic treatment for 30min, respectively, and then dried at 60℃ in vacuum for 12h.

[0086] (2) 0.6mmol of Ni(NO3)2·6H2O, 1.2mmol of Co(NO3)2·6H2O, 12mmol of CO(NH2)2 and 6mmol of NH4F were dissolved in 60mL of deionized water, and the solution was stirred uniformly using a magnetic stirrer to obtain a reaction mixture; then the mixed solution was transferred to a 100mL stainless steel autoclave with a Teflon liner, and the foam nickel cleaned in step (1) was immersed in the reaction mixture, and kept at 150℃ for 5h. After the autoclave was naturally cooled to room temperature, it was ultrasonically cleaned with distilled water and anhydrous ethanol, respectively, and then fully dried in a vacuum drying oven at 60℃ to obtain the NiCo-LDH / NF precursor.

[0087] (3) 350mg of triphenylphosphine and the NiCo-LDH / NF precursor produced in step (2) were placed in the upstream and downstream of a tube furnace, respectively, then purged with nitrogen at a flow rate of 200sccm for about 15min, and then heated to 300℃ at a heating rate of 2℃·min -1 -1 under a flow rate of 50sccm, and kept for 2h. Finally, the NiCoP / NF catalyst was obtained after low-temperature phosphating treatment of the substrate.

[0088] Analysis Example 1

[0089] (1) The Ru / La-NiCoP / NF catalyst obtained in Example 1 was characterized; the SEM image is shown in Figure 1 .

[0090] From Figure 1 , it can be seen that the Ru / La-NiCoP / NF catalyst has a 3D interconnected nanosheet structure. The 3D interconnected nanosheet structure is a three-dimensional network structure formed by the mutual connection of multiple nanoscale thin sheets; the thickness of the nanoscale thin sheets is 10-50 nm, and the width is 5-15 µm; the nanoscale thin sheets are interpenetrated and crosslinked with each other to form a 3D interconnected nanosheet structure. This structure can significantly increase the surface area of the Ru / La-NiCoP / NF catalyst, thereby providing a larger contact area for the reaction.

[0091] (2) The materials prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to LSV testing; the overpotential comparison results measured are shown in Figure 2 and Table 1.

[0092] Among them, the LSV test conditions are: the electrolyte is 1M KOH, the working electrode is a self-made electrode (20 20 mm prepared in Examples 1-3 and Comparative Examples 1-4), the counter electrode is a pure nickel sheet of 20 20 mm, and the reference electrode is a Hg / HgO electrode.

[0093] Table 1 Comparison of catalyst activity

[0094]

[0095] From Table 1, it can be seen that the Ru / La-NiCoP / NF of Example 1 has the best HER activity, and the overpotential of 10 mA·cm -2 is only 20 mV, which is better than that of NiCoP / NF (200 mV), and the overpotential at a current density of 1000 mA·cm -2 is only 248 mV. This indicates that the Ru / La-NiCoP / NF catalyst can adapt to a wide range of working current densities and meet the needs of industrial electrolytic cells above 5 kA / m². Compared with the Ru-NiCoP / NF, La-NiCoP / NF, Ru / La-NiCo / NF, and NiCoP / NF catalysts prepared in Comparative Examples 1-4, the Ru / La-NiCoP / NF has the lowest overpotential, which means that the introduction of Ru and La plays an important role in enhancing the HER reaction activity. Among them, the Ru doping ratio of Example 3 is significantly increased compared with Example 1 and Example 2, but its performance does not change much, which is because the increase of Ru content will lead to the decrease of Ru dispersion in the catalyst, resulting in that the performance does not change much.

[0096] From Figure 2 It can also be seen from 2 The absolute value of the overpotential of the material prepared in Embodiments 1-3 is still less than 0.3 (vs. RHE) at a working current density of 10 kA / m² (1000 mA / cm 2 ) and can meet a large range of working current densities of 1-10 kA / m² (100-1000 mA / cm

[0097] (3) The Ru / La-NiCoP / NF catalyst obtained in Embodiment 1 was subjected to stability testing, and the results are shown in Figure 3

[0098] Among them, the stability test: test under the current density of 100 mA·cm -2 , and the total test time is 110 h.

[0099] From Figure 3 It can be seen from

[0100] In summary, in the above technical solution of the present application, the above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made under the technical concept of the present application, using the content of the present application specification and drawings, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.​

Claims

1. A method for preparing a Ru / La-NiCoP / BM catalyst, characterized in that, Including the following steps: A reaction mixture is provided; the reaction mixture comprises: nickel salt, cobalt salt, lanthanum salt, ammonium fluoride salt, urea and water; the molar ratio of the nickel salt, cobalt salt, lanthanum salt, ammonium fluoride salt and urea in the reaction mixture is (0.05~0.2):(0.1~0.25):(0.01~0.03):2:1; The substrate is immersed in the reaction mixture and subjected to hydrothermal treatment to obtain the La-NiCo-LDH / BM precursor; the substrate is one of nickel foam, nickel-iron foam, copper foam, nickel mesh, and nickel felt; the hydrothermal treatment temperature is 100~180℃; Using the La-NiCo-LDH / BM precursor as the working electrode, a three-electrode system was constructed and electrodeposition was performed to obtain Ru / La-NiCo-LDH / BM; the electrolyte for the electrodeposition process contained 200~800 µM RuCl3. The Ru / La-NiCo-LDH / BM and the phosphorus source were placed downstream and upstream of a tube furnace, respectively, and subjected to low-temperature phosphating treatment at 250~400℃ to obtain the Ru / La-NiCoP / BM catalyst.

2. The preparation method according to claim 1, characterized in that, The nickel salt is a nickel-containing nitrate, a nickel-containing sulfate, or a nickel-containing chloride; The cobalt salt is a cobalt-containing nitrate, a cobalt-containing sulfate, or a cobalt-containing chloride. The lanthanum salt is a lanthanum-containing nitrate, a lanthanum-containing sulfate, or a lanthanum-containing chloride.

3. The preparation method according to claim 1, characterized in that, The duration of the hydrothermal treatment is 4 to 8 hours.

4. The preparation method according to claim 1, characterized in that, The three-electrode system further includes: a graphite rod as the counter electrode and Hg / HgO as the reference electrode.

5. The preparation method according to claim 1, characterized in that, The deposition potential window range of the electrodeposition treatment is (0~0.2) to (-0.6~-0.8) V vs. RHE; the cycle period of the electrodeposition treatment is 9~11 cycles.

6. The preparation method according to claim 1, characterized in that, In the electrolyte, the concentration of KOH solution is 0.5~1.5 M; the concentration of RuCl3 is 200~800 µM.

7. The preparation method according to claim 1, characterized in that, The heating rate for the low-temperature phosphating treatment is 2~5℃·min. -1 The duration of the low-temperature phosphating treatment is 1 to 3 hours.

8. A Ru / La-NiCoP / BM catalyst, characterized in that, It was prepared using the method described in any one of claims 1-7 for the preparation of Ru / La-NiCoP / BM catalyst.

9. The Ru / La-NiCoP / BM catalyst according to claim 8, characterized in that, The Ru / La-NiCoP / BM catalyst has a 3D interconnected nanosheet structure; the 3D interconnected nanosheet structure is a three-dimensional network structure formed by interconnecting multiple nanoscale thin sheets; Ru is uniformly dispersed in the Ru / La-NiCoP / BM catalyst; the Ru doping ratio is 0.1~1%.

10. The application of the Ru / La-NiCoP / BM catalyst as described in claim 8 or 9 in hydrogen production by water electrolysis, characterized in that, The Ru / La-NiCoP / BM catalyst was used as the working electrode in an alkaline electrolytic cell to produce H2.

11. The application according to claim 10, characterized in that, The working current density of the working electrode is 1~10kA / m 2 .

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