Electrode Loaded with Amorphous Catalyst, Preparation Method Thereof and Application

Abstract

The present invention provides an electrode loaded with an amorphous catalyst, a preparation method thereof and an application. The preparation method includes: performing a first mixing of aluminum metal powder and magnesium metal powder to obtain a mixed aluminum-magnesium powder; spraying the mixed aluminum-magnesium powder onto at least one surface of a metallic nickel substrate by means of vacuum plasma spraying to obtain a metallic nickel substrate loaded with an aluminum-magnesium alloy transition layer; performing a second mixing of an amorphous metal source and an auxiliary agent to obtain a mixed amorphous powder; spraying the mixed amorphous powder onto one surface of the aluminum-magnesium alloy transition layer away from the metallic nickel substrate by means of cold spraying to obtain an amorphous catalyst layer, and thus obtaining a first electrode; and performing heat treatment and alkali immersion on the first electrode in sequence to obtain an electrode loaded with an amorphous catalyst. In the present invention, an aluminum-magnesium alloy transition layer is first prepared on the metallic nickel substrate, and then an amorphous catalyst layer is prepared by means of cold spraying technology, effectively enhancing the bonding force between the amorphous catalyst layer and the substrate.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen production by electrolyzing water, and more particularly, to an electrode loaded with an amorphous catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] The shortage of fossil fuels and the subsequent environmental pollution have sparked great interest in finding sustainable, clean, and efficient energy sources to meet existing energy demands. Electrolyzing water is an efficient and clean technology for obtaining high-purity hydrogen, and using efficient electrocatalysts in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) to overcome thermodynamic barriers is an important way to improve economic efficiency.

[0003] Therefore, how to improve the catalytic activity and stability of electrode materials has become an important research direction for the industrialization of hydrogen production by electrolyzing water. Noble metal Pt-based catalysts have been applied to OER and HER due to their good catalytic performance, but their large-scale application is limited by their high cost. Therefore, the development of new non-precious metal electrode materials with low cost and good catalytic performance has become a research hotspot.

[0004] Among various types of catalysts, due to the special structural characteristics of a large number of randomly oriented bonds and surface-exposed defects, amorphous materials can significantly increase the amount of active sites and optimize the adsorption and desorption of reactants. Many amorphous materials can be used for efficient electrocatalytic water splitting. However, due to the unstable structure of amorphous catalytic powders, the crystallinity of the materials will rapidly increase in a high-temperature environment, resulting in the disappearance of their intrinsic special properties. Therefore, it is difficult to load amorphous materials on the surface of a metal mesh with high bonding strength by traditional thermal spraying or high-temperature calcination methods and further use them in actual hydrogen production by electrolyzing water.

[0005] Based on this, how to optimize the preparation method of the electrodes used in the field of hydrogen production by electrolyzing water so that they can load amorphous catalysts with high catalytic activity with high bonding strength, thereby showing higher and more stable OER and HER catalytic activities, is one of the important technical problems to be solved in this field. Summary of the Invention

[0006] The main purpose of the present invention is to provide an electrode loaded with an amorphous catalyst, a preparation method thereof, and an application thereof, so as to solve the problem in the prior art that the binding force between the electrodes used for hydrogen production by electrolyzing water and the amorphous catalyst is weak, resulting in low and unstable electrocatalytic activity.

[0007] To achieve the above object, a first aspect of the present invention provides a method for preparing an electrode loaded with an amorphous catalyst, comprising: Step S1, performing a first mixing of aluminum metal powder and magnesium metal powder to obtain a mixed aluminum-magnesium powder; Step S2, by means of vacuum plasma spraying, spraying the mixed aluminum-magnesium powder on at least one surface of a metallic nickel substrate to obtain a metallic nickel substrate loaded with an aluminum-magnesium alloy transition layer; Step S3, performing a second mixing of an amorphous metal source and an auxiliary agent to obtain a mixed amorphous powder; Step S4, by means of cold spraying, spraying the mixed amorphous powder on the surface of the aluminum-magnesium alloy transition layer away from the metallic nickel substrate to obtain an amorphous catalyst layer, and further obtaining a first electrode; Step S5, performing heat treatment and alkali immersion on the first electrode in sequence to obtain an electrode loaded with an amorphous catalyst; the amorphous metal source includes a first amorphous metal source and a second amorphous metal source, and the weight ratio of the first amorphous metal source to the second amorphous metal source is 1:(1-2.5); the first amorphous metal source is a nickel source, and the second amorphous source is one or more of a noble metal source and / or a transition metal source other than the nickel source.

[0008] Further, the second amorphous source is one or more of metal sources with atomic numbers from 22 to 30 other than the nickel source; preferably, the second amorphous metal source is selected from one or more of a cobalt metal source, an iron metal source, and a copper metal source; more preferably, the second amorphous metal source is a cobalt metal source, an iron metal source, and a copper metal source, and the weight ratio of the cobalt metal source, the iron metal source, and the copper metal source is 1:(0.4-0.6):1; further preferably, the first amorphous metal source and the second amorphous metal source are each independently one or several forms of nitrate, sulfate, acetate, acetylacetonate, and chloride.

[0009] Further, in Step S1, the weight ratio of the aluminum metal powder to the magnesium metal powder is 1:(0.1-10), preferably 1:(1-2); preferably, the mesh numbers of the aluminum metal powder and the magnesium metal powder are each independently 100 mesh to 500 mesh; more preferably, the first mixing method is ball milling, and the rotation speed of the ball milling is 150 r / min to 500 r / min, the time is 0.5 h to 10 h, and the ball milling beads are zirconia beads with a diameter of 10 mm to 30 mm; further preferably, the dispersion liquid used for ball milling is ethanol, and the weight ratio of ethanol to the sum of the weights of the aluminum metal powder and the magnesium metal powder is 1:(6-12).

[0010] Further, in step S2, the power of the vacuum plasma spraying is 20 kW to 25 kW, the powder feeding rate is 10 g / min to 100 g / min, the distance between the spray head and the nickel metal substrate is 25 cm to 80 cm, and the moving rate of the spray gun is 50 cm / s to 80 cm / s; preferably, in the vacuum plasma spraying, the process gas for generating plasma is a H2 / Ar mixed gas, and the total flow rate of the H2 / Ar mixed gas is 8 L / min to 15 L / min; more preferably, in the H2 / Ar mixed gas, the volume ratio of H2 to Ar is 1:(2 to 10).

[0011] Further, in step S3, the molar ratio of the amorphous metal source to the additive is (0.2 to 10):1, preferably (2.0 to 6.0):1; preferably, the additive is selected from one or more of sodium borohydride, thiourea, and sodium hypophosphite, preferably sodium borohydride; more preferably, the second mixing method is ball milling, and the rotation speed of the ball milling is 150 r / min to 500 r / min, the time is 0.5 h to 10 h, and the ball milling beads are zirconia beads with a diameter of 10 mm to 30 mm; further preferably, the dispersion liquid used for ball milling is ethanol, and the weight ratio of ethanol to the total weight of the amorphous metal source and the additive is 1:(4 to 8).

[0012] Further, in step S4, the pressure of the cold spraying is 1 MPa to 10 MPa, the temperature is 400 °C to 600 °C, the distance between the spray head and the aluminum-magnesium alloy transition layer is 10 cm to 60 cm, the powder feeding rate is 10 g / min to 100 g / min, and the moving rate of the spray gun is 20 cm / s to 60 cm / s; preferably, the propelling gas used for the cold spraying is an N2 / He mixed gas, and in the N2 / He mixed gas, the volume ratio of N2 to He is 1:(0.1 to 10), more preferably 1:(4 to 5).

[0013] Further, in step S5, the temperature of the heat treatment is 250 °C to 350 °C, the time is 0.5 to 5 h, and the atmosphere used is selected from one or more of air atmosphere, vacuum atmosphere, nitrogen atmosphere, argon atmosphere, hydrogen atmosphere, and helium atmosphere; and / or, the mass concentration of the alkali solution used for alkali leaching is 10 wt% to 30 wt%, and the alkali leaching is carried out at 25 °C to 80 °C for 6 h to 24 h.

[0014] The second aspect of the present invention provides an electrode loaded with an amorphous catalyst, including a nickel metal substrate, and the electrode loaded with the amorphous catalyst is prepared by the preparation method of the electrode loaded with the amorphous catalyst described above.

[0015] Further, the electrode loaded with the amorphous catalyst further includes an alloy transition layer and an amorphous catalyst layer loaded on at least one surface of the metal nickel substrate. The alloy transition layer is arranged in contact with the metal nickel substrate, and the amorphous catalyst layer is arranged on the surface of the alloy transition layer away from the metal nickel substrate. Preferably, the thickness of the amorphous catalyst layer is 10 μm to 150 μm, more preferably 40 μm to 50 μm.

[0016] The third aspect of the present invention provides an application of the above-mentioned electrode loaded with the amorphous catalyst as an electrode in an electrolytic water hydrogen production system, and the electrolytic water hydrogen production system is an alkaline electrolytic water system or an anion exchange membrane electrolytic water system. Preferably, the electrolytic water hydrogen production system is an alkaline electrolytic water system, and the electrode loaded with the amorphous catalyst is used as an oxygen evolution working electrode and / or a hydrogen evolution working electrode in the alkaline electrolytic water system; and / or, the electrolytic water hydrogen production system is an anion exchange membrane electrolytic water system, and the electrode loaded with the amorphous catalyst is used as a self-supporting oxygen evolution electrode and / or a self-supporting hydrogen evolution electrode in the anion exchange membrane electrolytic water system.

[0017] Applying the technical solution of the present invention, by first preparing an aluminum-magnesium alloy transition layer on the metal nickel substrate and then preparing an amorphous catalyst layer through a cold spraying technique, the bonding force between the amorphous catalyst layer and the substrate is effectively enhanced, taking into account both the bonding property between the amorphous catalyst and the metal nickel substrate and retaining the unique high catalytic activity of the amorphous structure, thereby significantly improving the catalytic activity and cyclic stability of the electrode. Description of the Drawings

[0018] The specification drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0019] Figure 1 It is the SEM morphology characterization result of the electrode loaded with the amorphous catalyst obtained in Example 1 of the present invention. Detailed Embodiments

[0020] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0021] As described in the background art, there is a problem in the prior art that the binding force between the electrodes used for hydrogen production by electrolyzing water and the amorphous catalyst is weak, resulting in low and unstable electrocatalytic activity. To solve the above technical problems, a first aspect of the present invention provides a method for preparing an electrode loaded with an amorphous catalyst, including: Step S1, performing a first mixing of aluminum metal powder and magnesium metal powder to obtain a mixed aluminum-magnesium powder; Step S2, spraying the mixed aluminum-magnesium powder on at least one surface of a metal nickel substrate by means of vacuum plasma spraying to obtain a metal nickel substrate loaded with an aluminum-magnesium alloy transition layer; Step S3, performing a second mixing of an amorphous metal source and an auxiliary agent to obtain a mixed amorphous powder; Step S4, spraying the mixed amorphous powder on the surface of the aluminum-magnesium alloy transition layer away from the metal nickel substrate by means of cold spraying to obtain an amorphous catalyst layer, and further obtaining a first electrode; Step S5, performing heat treatment and alkali immersion on the first electrode in sequence to obtain an electrode loaded with an amorphous catalyst; the amorphous metal source includes a first amorphous metal source and a second amorphous metal source, and the weight ratio of the first amorphous metal source to the second amorphous metal source is 1:(1-2.5); the first amorphous metal source is a nickel source, and the second amorphous source is one or more of a noble metal source and / or a transition metal source other than the nickel source.

[0022] The present invention selects a low-melting-point aluminum-magnesium alloy as the connection transition layer between the amorphous catalyst and the metal nickel substrate. First, a low-melting-point aluminum-magnesium alloy transition layer is formed by means of vacuum plasma spraying. Then, a nickel-based amorphous catalyst is prepared. By means of the high-pressure cold spraying process, the amorphous catalyst is made to impact the low-melting-point aluminum-magnesium alloy transition layer at a high speed, and is embedded on the surface of the transition layer alloy. The instantaneous high temperature generated only crystallizes the interface part where the amorphous compound contacts the aluminum-magnesium alloy, which is beneficial to the combination of the catalyst and the metal nickel substrate. At the same time, the remaining main part of the catalyst still maintains a highly amorphous state, and its related special catalytic properties are retained. The thus obtained electrode loaded with an amorphous catalyst not only takes into account the binding property with the substrate, but also retains the unique catalytic performance of the amorphous catalyst structure, and thus exhibits excellent catalytic activity and stability in both HER and OER.

[0023] Specifically, in the formation process of the aluminum-magnesium alloy transition layer, compared with traditional powder metallurgy methods such as coating and sintering, vacuum plasma spraying can avoid the oxidation of the aluminum-magnesium alloy during thermal spraying or sintering, which may lead to the formation of a brittle oxide coating on the electrode surface and prevent its peeling during subsequent applications. Thus, the bonding strength between the aluminum-magnesium alloy as the transition coating and the substrate is effectively improved, facilitating the further construction of a highly stable amorphous coating on the surface. When using cold spraying to embed the amorphous catalyst on the surface of the transition layer alloy, the high-pressure conditions during cold spraying can ensure that the amorphous catalyst achieves a special state where crystallization occurs at the interface and the main part remains amorphous, thereby achieving both high bonding strength and high catalytic activity. Subsequently, heat treatment is used to eliminate the stress generated by mechanical impact, and then alkali leaching is carried out to remove the aluminum element in the aluminum-magnesium alloy, correcting the problems of structural damage, reduced catalytic activity, and stability caused by the high metal activity of the aluminum-based material, which is prone to dissolution in acidic or alkaline electrolytes.

[0024] In particular, on the basis of the nickel-based amorphous catalyst, a second amorphous metal source is introduced, and the weight ratio of the first amorphous metal source, namely the nickel source, to the second amorphous metal source is controlled to be 1:(1 - 2.5). By adding another heteroatom metal with a specific ratio, the lattice arrangement order can be reduced, thereby increasing the degree of crystal disorder of the material and ultimately enhancing the catalytic performance of the formed amorphous material. Regarding the type of the second amorphous metal source, since nickel, as the first amorphous metal source, itself belongs to transition metals, the inventors have preferably selected transition metals other than nickel and noble metals with excellent intrinsic catalytic performance as the second amorphous metal source to cooperate with it, thereby more significantly enhancing the electrocatalytic activity of the electrode loaded with the amorphous catalyst.

[0025] In practical applications, the noble metal source includes noble metals ruthenium, rhodium, palladium, osmium, iridium, and platinum. The transition metal sources other than the nickel source include transition metals titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, and zinc.

[0026] In addition, the preparation process described in the present invention has the advantages of simple process, low raw material cost, short preparation cycle, and can achieve large-scale preparation in equal proportion, providing a useful reference for the industrial preparation and application of amorphous catalyst electrodes. Compared with the powder amorphous catalyst prepared by traditional methods, the electrode prepared based on the amorphous catalyst in the present invention has catalytic performance and structural strength that meet the requirements of the electrodes used in industrial electrolysis of water, providing a new choice for commercial electrolytic cell electrodes.

[0027] In several typical embodiments, in order to more significantly optimize the electronic structure of the obtained amorphous catalyst and thus comprehensively enhance the catalytic activities of HER and OER, the second amorphous source is preferably one or more metal sources with atomic numbers from 22 to 30 other than the nickel source.

[0028] In a more typical embodiment, the second amorphous metal source is selected from one or more of a cobalt metal source, an iron metal source, and a copper metal source because the d-orbital electron configuration of nickel in the divalent state is 3d 8 , the d-orbital electron configuration of the divalent cobalt source is 3d 7 , the d-orbital electron configuration of the trivalent iron source is 3d 5 , and the d-orbital electron configuration of the divalent copper source is 3d 9 . They all belong to the metals on the left side of the transition series with unfilled or half-filled d-orbitals in Engel Brewer's valence bond theory. When amorphous compounds are formed by doping and mixing these metal sources with such special d-orbital electron structures, the d-orbital electrons of the above-mentioned metal ions can exchange to form electron clouds, and energy level splitting and changes in the energy band structure can occur, thereby optimizing their overall electronic properties. Furthermore, the interaction between them is enhanced, thereby improving the adsorption of water molecules by the formed amorphous catalyst layer, and making the reaction between H + and OH - with d-orbital electrons more likely to occur, and ultimately comprehensively improving their HER and OER catalytic activities. In particular, during the OER process, it is further preferred that the second amorphous metal source contains a cobalt metal source, an iron metal source, and a copper metal source at the same time, and the weight ratio of the cobalt metal source, the iron metal source, and the copper metal source is 1:(0.4 - 0.6):1. Since the above-mentioned transition metals with unfilled d-orbitals are either in tetrahedral coordination or octahedral coordination, when they are in this precise synergistic doping ratio, the metals can cooperate with each other to increase the number of octahedral sites during the catalytic process, so it is easier to construct oxygen vacancies, optimize the adsorption of H2O, and promote the occurrence of OER, and the catalytic activity is particularly significant.

[0029] Further preferably, the first amorphous metal source and the second amorphous metal source are each independently in the form of one or several of nitrates, sulfates, acetates, acetylacetonates, and chlorides. As carriers of the above-mentioned various amorphous metal sources, these salts can not only promote the formation of the amorphous catalyst layer, but also further optimize the performance of the catalyst through their decomposition products, making the obtained electrode exhibit more excellent catalytic activity.

[0030] In the preparation process of the mixed aluminum-magnesium powder, in order to obtain an aluminum-magnesium alloy transition layer with better bonding and conductivity subsequently, it is preferred that the weight ratio of aluminum metal powder to magnesium metal powder in step S1 is 1:(0.1 - 10), preferably 1:(1 - 2). The aluminum-magnesium alloy transition layer obtained by mixing and spraying in this weight ratio can provide a more stable bonding effect between the amorphous catalyst layer and the metal nickel substrate, thereby enhancing the existence stability of the amorphous catalyst layer and the overall catalytic performance of the electrode. And it is preferred that the mesh numbers of the aluminum metal powder and the magnesium metal powder are independently 100 mesh - 500 mesh, which can ensure that the aluminum-magnesium alloy transition layer formed during the vacuum plasma spraying process has better uniformity and denseness, thus improving the stability and catalytic efficiency of the electrode.

[0031] Furthermore, for the mixing process of the aluminum-magnesium powder, in order to improve the uniformity of the subsequently obtained aluminum-magnesium alloy transition layer and promote the optimization of the microstructure, so that the bonding between the amorphous catalyst layer and the metal nickel substrate is more stable, it is preferred that the first mixing method is ball milling, and the rotation speed of the ball milling is 150 r / min - 500 r / min, preferably 250 ± 50 r / min; the time is 0.5 h - 10 h, preferably 2 h - 3 h; the ball milling beads are zirconia beads with a diameter of 10 mm - 30 mm. More preferably, the dispersion liquid used for ball milling is ethanol, and the weight ratio of ethanol to the sum of the weights of the aluminum metal powder and the magnesium metal powder is 1:(6 - 12), so as to improve the dispersion uniformity of the mixed ball milling system during the first mixing process, make the particle size of the obtained mixed aluminum-magnesium powder more uniform, and further optimize the microstructure of the aluminum-magnesium alloy transition layer, enhancing the existence stability of the amorphous catalyst layer.

[0032] In several typical implementation modes, in order to further optimize the structure of the obtained aluminum-magnesium alloy transition layer and reduce the formation of defects, step S1 further includes drying the obtained mixed aluminum-magnesium powder, and preferably the drying method is vacuum drying, the temperature is 25°C - 60°C, more preferably 50°C - 60°C, and the time is 0.5 - 24 h, more preferably 12 ± 2 h.

[0033] During the formation process of the aluminum-magnesium alloy transition layer, that is, during the vacuum plasma spraying process, the inventor preferably selects the power of the vacuum plasma spraying to be 20 kW - 25 kW through a large number of experiments; the powder feeding rate is 10 g / min - 100 g / min, more preferably 50 ± 10 g / min; the distance between the spray head and the metal nickel substrate is 25 cm - 80 cm, more preferably 60 ± 10 cm; the moving speed of the spray gun is 50 cm / s - 80 cm / s, more preferably 50 cm / s - 60 cm / s. These spraying parameters can promote the improvement of the uniformity and denseness of the sprayed aluminum-magnesium alloy transition layer, and also make the subsequent amorphous catalyst layer bond more tightly on it, thereby more effectively improving the bonding force between the amorphous catalyst layer and the metal nickel substrate, and optimizing the overall catalytic activity and cycle stability of the obtained electrode.

[0034] During the spraying process, in order to better protect the mixed aluminum-magnesium powder from oxidation, so as to make the microstructure of the obtained aluminum-magnesium alloy transition layer denser, with less impurities and being more convenient for subsequent alkali leaching to remove unstable aluminum, and obtain an electrode with higher catalytic activity and stability, in vacuum plasma spraying, it is preferred that the process gas for generating plasma is a H2 / Ar mixture, and the total flow rate of the H2 / Ar mixture is 8 L / min to 15 L / min. In several typical embodiments, it is more preferred that the volume ratio of H2 to Ar in the H2 / Ar mixture is 1:(2 - 10). The H2 / Ar mixture in this ratio can make the uniformity and denseness of the formed aluminum-magnesium alloy transition layer higher, while effectively utilizing the reduction effect of hydrogen, further optimizing the microstructure of the obtained transition layer, reducing impurities therein, and ultimately improving the overall performance of the obtained electrode.

[0035] In several typical embodiments, preferably based on the weight of the metal nickel substrate being 100%, the loading amount of the aluminum-magnesium alloy transition layer formed by vacuum plasma spraying is 100 g / m 2 ~120 g / m 2 . The screening of the loading amount within this range can make the subsequent amorphous catalyst layer loaded thereon better combined with it, and at the same time make the removal of aluminum in the aluminum-magnesium alloy transition layer more complete during the final alkali leaching process, and obtain an electrode with higher catalytic activity and cycle stability.

[0036] During the preparation process of the mixed amorphous powder, it is preferred that the molar ratio of the amorphous metal source to the additive is (0.2 - 10):1, and more preferably (2.0 - 6.0):1, so as to better play the role of the additive and further optimize the obtained mixed amorphous powder, that is, the electronic structure, chemical structure, and microscopic morphology structure of the amorphous catalyst precursor, and optimize its catalytic activity and cycle stability in the electrode system.

[0037] In several typical embodiments, the preferred auxiliary agent is selected from one or more of sodium borohydride, thiourea, and sodium hypophosphite, and more preferably sodium borohydride. This is because sodium borohydride has strong reducibility at room temperature and can more quickly reduce transition metal ion salts to metals, resulting in rapid nucleation and growth of materials in the liquid phase, inhibiting the growth process of the ordered structure. Therefore, a highly amorphous structure can be formed, and various elements in it are uniformly and disorderly arranged, which ultimately facilitates the in-situ self-adaptive reconstruction of the amorphous structure into a catalytic active phase during the electrochemical reaction. Further preferably, the second mixing method is ball milling, and the rotation speed of the ball milling is 150 r / min to 500 r / min, more preferably 150 r / min to 200 r / min; the time is 0.5 h to 10 h, more preferably 0.5 h to 1 h; the ball milling beads are zirconia beads with a diameter of 10 mm to 30 mm. The above ball milling conditions can improve the mixing uniformity of the amorphous metal source and the auxiliary agent, and obtain an amorphous catalyst with higher structural stability and integrity. At the same time, during the subsequent cold spraying process, part of the amorphous catalyst that impacts and embeds on the surface of the aluminum-magnesium alloy transition layer can crystallize more fully, improving its bonding strength, and further enhancing its activity and stability during the catalytic process. In several more typical embodiments, the preferred dispersion liquid used for ball milling is ethanol, and the weight ratio of ethanol to the total weight of the amorphous metal source and the auxiliary agent is 1:(4 - 8), so as to further improve the mixing uniformity of the amorphous metal source and the auxiliary agent, optimize the microstructure of the formed amorphous catalyst layer, and enhance its bonding strength.

[0038] In order to remove the moisture of the obtained mixed amorphous powder, facilitate the subsequent cold spraying, and reduce the problems of reduced catalytic activity and instability caused by the generation of impurities, preferably, after obtaining the mixed amorphous powder, step S3 further includes vacuum drying it, and the temperature of the vacuum drying is 25°C to 60°C, more preferably 55°C to 60°C; the time is 0.5 to 24 h, more preferably 6 ± 1 h.

[0039] During the process of cold spraying to form the amorphous catalyst layer in step S4, through a large number of experiments, the inventor preferably selects the pressure of cold spraying to be 1 MPa to 10 MPa, more preferably 4 MPa to 5 MPa; the temperature is 400 °C to 600 °C; the distance between the nozzle and the aluminum-magnesium alloy transition layer is 10 cm to 60 cm, more preferably 50 cm to 60 cm; the powder feeding rate is 10 g / min to 100 g / min, more preferably 25 ± 5 g / min; the moving rate of the spray gun is 20 cm / s to 60 cm / s, more preferably 40 ± 5 cm / s. The above spraying parameters can cause the amorphous mixed powder that collides with the aluminum-magnesium alloy transition layer at a high speed to crystallize, improve the bonding property, and at the same time enable most of the main catalyst powders in the formed amorphous catalyst layer to well maintain the amorphous state, so that the obtained electrode loaded with the amorphous catalyst can take into account high catalytic activity and cyclic stability. Moreover, the selection of the above parameters can also promote the improvement of the microscopic uniformity and denseness of the formed amorphous catalyst layer itself, thereby more significantly improving the catalytic activity and stability of the finally obtained electrode.

[0040] Moreover, in order to more effectively prevent the cold-sprayed amorphous material from hitting the nickel-magnesium coating and causing its oxidation to form a ceramic-like oxide layer, so as to improve the bonding force between the amorphous material and the nickel-magnesium coating substrate, it is preferred that the propelling gas used for cold spraying is a N2 / He mixed gas, and in the N2 / He mixed gas, the volume ratio of N2 to He is 1:(0.1 - 10), more preferably 1:(4 - 5).

[0041] In several typical embodiments, it is preferred that in step S5, the temperature of the heat treatment is 250 °C to 350 °C, the time is 0.5 to 5 h, and the atmosphere used is selected from one or more of air atmosphere, vacuum atmosphere, nitrogen atmosphere, argon atmosphere, hydrogen atmosphere, and helium atmosphere. The setting of the above heat treatment conditions can better eliminate the internal stress generated in the amorphous catalyst layer during the cold spraying process, thereby more significantly optimizing its microscopic structure and improving its catalytic activity and stability. In order to more thoroughly remove the aluminum in the aluminum-magnesium alloy transition layer formed in step S2, and further better avoid the problem of catalytic deactivation caused by the possible alkali dissolution / acids dissolution of aluminum. At the same time, in order to more effectively remove the impurities on the surface of the finally obtained electrode, optimize its surface state, and improve its catalytic activity and stability, it is preferred that the mass concentration of the alkali solution used for alkali leaching is 10 wt% to 30 wt%, and the alkali leaching is carried out at 25 °C to 80 °C for 6 h to 24 h; more preferably, the alkali leaching is carried out at 25 °C to 40 °C for 6 h to 10 h.

[0042] Furthermore, on the basis of the above alkali leaching conditions, it is preferred that the alkali solution further includes a corrosion inhibitor with a mass concentration of 5 wt% to 6 wt%, so as to better control the process of removing aluminum and impurities by alkali leaching and obtain an electrode with better comprehensive performance. More preferably, the corrosion inhibitor is potassium sodium tartrate.

[0043] The second aspect of the present invention provides an electrode loaded with an amorphous catalyst, including a metallic nickel substrate, and the electrode loaded with the amorphous catalyst is prepared by the preparation method of the above-mentioned electrode loaded with the amorphous catalyst. The obtained electrode has an amorphous catalyst layer with high catalytic activity and strong binding force, so it can exhibit high catalytic activity and cyclic stability in various electrocatalytic reactions.

[0044] Furthermore, the electrode loaded with the amorphous catalyst further includes an alloy transition layer and an amorphous catalyst layer loaded on at least one surface of the metallic nickel substrate, and the alloy transition layer is arranged in contact with the metallic nickel substrate, and the amorphous catalyst layer is arranged on the surface of the alloy transition layer away from the metallic nickel substrate. With the above structural design, using the alloy transition layer with good conductivity as the intermediate layer between the catalyst layer and the substrate layer not only significantly enhances the binding force between the amorphous catalyst layer and the substrate, but also well protects the conductivity of the electrode, thereby enabling the obtained electrode to have both high catalytic activity and excellent stability.

[0045] In several preferred embodiments, in order to better coordinate the mechanical properties of each layer with the metallic nickel matrix, make their combination closer, and have higher structural stability during the electrocatalytic process, the thickness of the amorphous catalyst layer is 10 μm to 150 μm, more preferably 40 μm to 50 μm.

[0046] The third aspect of the present invention provides an application of the above-mentioned electrode loaded with the amorphous catalyst as an electrode in an electrolytic water hydrogen production system, and the electrolytic water hydrogen production system is an alkaline electrolytic water system or an anion exchange membrane electrolytic water system. The electrode obtained by the present invention not only has high catalytic activity, but also can be applied to various catalytic systems for electrolytic water, including conditions of high pressure, high temperature and different pH values. In practical applications, such an electrode can significantly reduce the cost of electrolytic water hydrogen production, improve the hydrogen production rate and purity, thereby being able to better support the sustainable production of hydrogen energy and laying a solid foundation for the wide application and sustainable development of hydrogen energy.

[0047] In a typical implementation manner, the electrolytic water hydrogen production system is an alkaline electrolytic water system, and the electrode loaded with the amorphous catalyst serves as an oxygen evolution working electrode and / or a hydrogen evolution working electrode in the alkaline electrolytic water system. And, in another typical implementation manner, the electrolytic water hydrogen production system is an anion exchange membrane electrolytic water system, and the electrode loaded with the amorphous catalyst serves as a self-supporting oxygen evolution electrode and / or a self-supporting hydrogen evolution electrode in the anion exchange membrane electrolytic water system. That is to say, the electrode loaded with the amorphous catalyst prepared by the preparation method provided by the present invention exhibits special and excellent HER / OER bifunctional catalytic characteristics due to the above specific structure, and it exhibits excellent catalytic performance whether in the alkaline electrolytic water system or in the anion exchange membrane electrolytic water system.

[0048] The following further describes the present application in conjunction with specific embodiments, and these embodiments should not be construed as limiting the scope of protection required by the present application.

[0049] Unless otherwise defined, all professional terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0050] Example 1

[0051] A method for preparing an electrode loaded with an amorphous catalyst:

[0052] (1) 100 g of aluminum metal powder with a mesh number of 325, 200 g of magnesium metal powder with a mesh number of 325 (the weight ratio of aluminum metal powder to magnesium metal powder is 1:2), and 50 g of ethanol are mixed by ball milling (that is, the weight ratio of ethanol to the sum of the weights of the two metal powders is 1:6). The rotation speed of ball milling is 250 r / min, and the time is 2 h. Zirconium beads with a diameter of 20 mm are selected as ball milling beads. Then, the mixed powder is taken out for vacuum drying at a temperature of 60 °C for 12 h to obtain a mixed aluminum-magnesium powder;

[0053] (2) Using a nickel felt with a porosity of 80% as the metal nickel matrix, the above-mentioned mixed aluminum-magnesium powder is coated on the metal nickel matrix by vacuum plasma spraying and cladding. The power of vacuum plasma spraying is 25 kW, the process gas for generating plasma is a H2 / Ar mixed gas (H2:AR = 1:2, volume ratio), the total flow rate is 8 L / min, the powder feeding rate of the mixed aluminum-magnesium powder is 50 g / min, the distance between the nozzle and the metal nickel substrate is 60 cm, and the moving speed of the spray gun is 50 cm / s to obtain an aluminum-magnesium alloy transition layer, and its loading amount on the surface of the metal nickel substrate is 100 g / m 2 ;

[0054] (3) Using nickel chloride as the first amorphous metal source nickel source and cobalt chloride as the second amorphous metal source, 50 g of cobalt chloride, 50 g of nickel chloride (the weight ratio of the first amorphous metal source to the second amorphous metal source is 1:1), 25 g of ethanol, and 5 g of sodium borohydride are mixed and prepared into an amorphous catalyst by ball milling (that is, the molar ratio of the amorphous metal source and the additive is 5.83:1, and the weight ratio of ethanol to the sum of the weights of the amorphous metal source and the additive is 1:4.2). The rotation speed of ball milling is 150 revolutions per minute, and the time is 1 h. Zirconium beads with a diameter of 20 mm are selected. Then, the mixed powder is taken out for vacuum drying at a temperature of 60 °C for 6 h to obtain a mixed amorphous powder;

[0055] (4) By means of high-pressure cold spraying, the above-mentioned mixed amorphous powder is sprayed on the surface of the aluminum-magnesium alloy transition layer away from the side of the nickel-based metal substrate. The propulsion gas for high-pressure cold spraying is a N2 / He mixture (N2:He = 1:4, volume ratio), the pressure is 4 MPa, the cold spraying temperature is 400 °C, the distance between the nozzle and the aluminum-magnesium alloy transition layer is 50 cm, the powder feeding rate is 25 g / min, and the moving rate of the spray gun is 40 cm / s, obtaining an amorphous catalyst layer with a thickness of 40 μm, and then obtaining the first electrode;

[0056] (5) Eliminate the stress generated by mechanical impact during the cold spraying process through low-temperature annealing heat treatment. The annealing heat treatment temperature is 250 °C, the time is 0.5 h, and the atmosphere is a nitrogen atmosphere; then, after alkali leaching to remove the aluminum element in the aluminum-magnesium alloy, a nickel-cobalt amorphous electrode is obtained. The alkali solution required for alkali leaching treatment is a 10 wt% potassium hydroxide solution, the treatment temperature is 25 °C, the treatment duration is 6 h, and 5 wt% of potassium sodium tartrate is added to the alkali solution as a corrosion inhibitor, and finally an electrode loaded with an amorphous catalyst is obtained.

[0057] The SEM morphological characterization results of the obtained electrode loaded with an amorphous catalyst are shown in Figure 1 .

[0058] Example 2

[0059] A preparation method of an electrode loaded with an amorphous catalyst:

[0060] The difference between this example and Example 1 is only that: in step (3), the second amorphous metal source is changed to ferric chloride, and 50 g of ferric chloride, 50 g of nickel chloride, 25 g of ethanol, and 5 g of sodium borohydride are mixed and then an amorphous catalyst is prepared by ball milling.

[0061] At this time, the molar ratio of the amorphous metal source and the auxiliary agent is 5.24:1.

[0062] Example 3

[0063] A preparation method of an electrode loaded with an amorphous catalyst:

[0064] The difference between this example and Example 1 is only that: in step (3), the second amorphous metal source is changed to ferric chloride, copper chloride, and cobalt chloride, and 50 g of copper chloride, 25 g of ferric chloride, 50 g of cobalt chloride, 50 g of nickel chloride, 25 g of ethanol, and 20 g of sodium borohydride are mixed and then an amorphous catalyst is prepared by ball milling.

[0065] At this time, the weight ratio of the first amorphous metal source to the second amorphous metal source is 1:2.5; the molar ratio of the amorphous metal source and the auxiliary agent is 2.45:1; the weight ratio of ethanol to the total weight of the amorphous metal source and the auxiliary agent is 1:7.8.

[0066] In addition, in the second amorphous metal source, the weight ratio of the cobalt metal source, the iron metal source, and the copper metal source is 1:0.5:1.

[0067] Example 4

[0068] A method for preparing an electrode loaded with an amorphous catalyst:

[0069] The difference between this example and Example 1 is only that: in step (3), the second amorphous metal source is changed to platinum chloride, and 50 g of platinum chloride, 50 g of nickel chloride, 25 g of ethanol, and 5 g of sodium borohydride are mixed and an amorphous catalyst is prepared by ball milling.

[0070] At this time, the molar ratio of the amorphous metal source to the auxiliary agent is 4.05:1.

[0071] Example 5

[0072] A method for preparing an electrode loaded with an amorphous catalyst:

[0073] The difference between this example and Example 1 is only that: in step (3), the second amorphous metal source is changed to iron chloride, copper chloride, and cobalt chloride, and 41.6 g of copper chloride, 41.6 g of iron chloride, 41.7 g of cobalt chloride, 50 g of nickel chloride, 25 g of ethanol, and 20 g of sodium borohydride are mixed and an amorphous catalyst is prepared by ball milling.

[0074] At this time, the weight ratio of the first amorphous metal source to the second amorphous metal source is 1:2.5; the molar ratio of the amorphous metal source to the auxiliary agent is 2.28:1.

[0075] The weight ratio of ethanol to the sum of the weights of the amorphous metal source and the auxiliary agent is 1:7.8.

[0076] In addition, in the second amorphous metal source, the weight ratio of the cobalt metal source, the iron metal source, and the copper metal source is 1:1:1.

[0077] Example 6

[0078] A method for preparing an electrode loaded with an amorphous catalyst:

[0079] The difference between this example and Example 1 is only in step (1), specifically:

[0080] Mix 60 g of aluminum metal powder with a mesh size of 100, 240 g of magnesium metal powder with a mesh size of 100 (the weight ratio of the aluminum metal powder to the magnesium metal powder is 1:4), and 150 g of ethanol by ball milling (i.e., the weight ratio of ethanol to the sum of the weights of the two metal powders is 1:2). The rotation speed of the ball milling is 100 r / min, and the time is 12 h. Select zirconia beads with a diameter of 20 mm as the ball milling beads. Then take out the mixed powder and perform vacuum drying at a temperature of 20 °C for 30 h to obtain the mixed aluminum-magnesium powder.

[0081] Example 7

[0082] A method for preparing an electrode loaded with an amorphous catalyst:

[0083] The difference between this example and Example 1 is only in step (1). Specifically:

[0084] Mix 200 g of aluminum metal powder with a mesh size of 100, 100 g of magnesium metal powder with a mesh size of 100 (the weight ratio of the aluminum metal powder to the magnesium metal powder is 1:0.5), and 20 g of ethanol by ball milling (i.e., the weight ratio of ethanol to the sum of the weights of the two metal powders is 1:15). The rotation speed of the ball milling is 600 r / min, and the time is 0.2 h. Select zirconia beads with a diameter of 20 mm as the ball milling beads. Then take out the mixed powder and perform vacuum drying at a temperature of 80 °C for 0.2 h to obtain the mixed aluminum-magnesium powder.

[0085] Example 8

[0086] A method for preparing an electrode loaded with an amorphous catalyst:

[0087] The difference between this example and Example 1 is only in step (2). Specifically:

[0088] Use a nickel felt with a porosity of 80% as the metal nickel substrate, and deposit the above-mentioned mixed aluminum-magnesium powder on the metal nickel substrate by vacuum plasma spraying and cladding. The power of the vacuum plasma spraying is 10 kW, the process gas for generating plasma is a H2 / Ar mixture (H2:AR = 1:1, volume ratio), the total flow rate is 6 L / min, the powder feeding rate of the mixed aluminum-magnesium powder is 150 g / min, the distance between the nozzle and the metal nickel substrate is 15 cm, and the moving rate of the spray gun is 40 cm / s to obtain an aluminum-magnesium alloy transition layer, and its loading amount on the surface of the metal nickel substrate is 128 g / m 2 .

[0089] Example 9

[0090] A method for preparing an electrode loaded with an amorphous catalyst:

[0091] The difference between this example and Example 1 is only in step (2). Specifically:

[0092] Using a nickel felt with a porosity of 80% as the metallic nickel matrix, the above-mentioned mixed aluminum-magnesium powder was melted and coated on the metallic nickel matrix by vacuum plasma spraying. The power of the vacuum plasma spraying was 40 kW, the process gas for generating plasma was a H2 / Ar mixture (H2:Ar = 1:15, volume ratio), the total flow rate was 18 L / min, the powder feeding rate of the mixed aluminum-magnesium powder was 5 g / min, the distance between the spray head and the metallic nickel substrate was 100 cm, and the moving rate of the spray gun was 100 cm / s, obtaining an aluminum-magnesium alloy transition layer, and its loading amount on the surface of the metallic nickel substrate was 86 g / m 2 。

[0093] Example 10

[0094] A method for preparing an electrode loaded with an amorphous catalyst:

[0095] The difference between this example and Example 1 is only in step (3). Specifically:

[0096] Nickel chloride was used as the first amorphous metal source nickel source, and cobalt chloride was used as the second amorphous metal source. 50 g of cobalt chloride, 50 g of nickel chloride (the weight ratio of the first amorphous metal source to the second amorphous metal source was 1:1), 65 g of ethanol, and 29.2 g of sodium borohydride were mixed and then an amorphous catalyst was prepared by ball milling (that is, the molar ratio of the amorphous metal source and the additive was 1:1, and the weight ratio of ethanol to the sum of the weights of the amorphous metal source and the additive was 1:2). The rotation speed of the ball milling was 100 revolutions per minute, the time was 12 h, zirconia beads with a diameter of 20 mm were selected, and then the mixed powder was taken out for vacuum drying. The temperature was 20 °C and the time was 30 h, obtaining a mixed amorphous powder.

[0097] Example 11

[0098] A method for preparing an electrode loaded with an amorphous catalyst:

[0099] The difference between this example and Example 1 is only in step (3). Specifically:

[0100] Nickel chloride was used as the first amorphous metal source nickel source, and cobalt chloride was used as the second amorphous metal source. 50 g of cobalt chloride, 50 g of nickel chloride (the weight ratio of the first amorphous metal source to the second amorphous metal source was 1:1), 10 g of ethanol, and 3.6 g of sodium borohydride were mixed and then an amorphous catalyst was prepared by ball milling (that is, the molar ratio of the amorphous metal source and the additive was 8:1, and the weight ratio of ethanol to the sum of the weights of the amorphous metal source and the additive was 1:10.4). The rotation speed of the ball milling was 600 revolutions per minute, the time was 0.2 h, zirconia beads with a diameter of 20 mm were selected, and then the mixed powder was taken out for vacuum drying. The temperature was 80 °C and the time was 0.2 h, obtaining a mixed amorphous powder.

[0101] Example 12

[0102] Preparation method of an electrode loaded with an amorphous catalyst:

[0103] The difference between this example and Example 1 is only in step (4). Specifically:

[0104] By means of high-pressure cold spraying, the above-mentioned mixed amorphous powder is sprayed on the surface of the aluminum-magnesium alloy transition layer on the side far from the metal nickel substrate. The propelling gas for high-pressure cold spraying is an N2 / He mixture (N2:He = 1:2, volume ratio), the pressure is 0.5 MPa, the cold spraying temperature is 200 °C, the distance between the nozzle and the aluminum-magnesium alloy transition layer is 5 cm, the powder feeding rate is 120 g / min, the moving rate of the spray gun is 10 cm / s, an amorphous catalyst layer with a thickness of 55 μm is obtained, and then the first electrode is obtained.

[0105] Example 13

[0106] Preparation method of an electrode loaded with an amorphous catalyst:

[0107] The difference between this example and Example 1 is only in step (4). Specifically:

[0108] By means of high-pressure cold spraying, the above-mentioned mixed amorphous powder is sprayed on the surface of the aluminum-magnesium alloy transition layer on the side far from the metal nickel substrate. The propelling gas for high-pressure cold spraying is an N2 / He mixture (N2:He = 1:8, volume ratio), the pressure is 12 MPa, the cold spraying temperature is 800 °C, the distance between the nozzle and the aluminum-magnesium alloy transition layer is 70 cm, the powder feeding rate is 5 g / min, the moving rate of the spray gun is 80 cm / s, an amorphous catalyst layer with a thickness of 34 μm is obtained, and then the first electrode is obtained.

[0109] Example 14

[0110] Preparation method of an electrode loaded with an amorphous catalyst:

[0111] The difference between this example and Example 1 is only in step (5). Specifically:

[0112] During the cold spraying process, the stress generated by mechanical impact is eliminated by low-temperature annealing heat treatment. The annealing heat treatment temperature is 200 °C, the time is 0.4 h, and the atmosphere is a nitrogen atmosphere; after that, the aluminum element in the aluminum-magnesium alloy is removed by alkali leaching to obtain a nickel-cobalt amorphous electrode. The alkali solution required for alkali leaching treatment is a 5 wt% potassium hydroxide solution, the treatment temperature is 10 °C, the treatment duration is 30 h, and 5 wt% potassium sodium tartrate is added to the solution as a corrosion inhibitor, and finally an electrode loaded with an amorphous catalyst is obtained.

[0113] Example 15

[0114] Preparation method of an electrode loaded with an amorphous catalyst:

[0115] The difference between this example and Example 1 lies only in step (5). Specifically:

[0116] During the cold spraying process, the stress generated by mechanical impact is eliminated through low-temperature annealing heat treatment. The annealing heat treatment temperature is 400 °C, the time is 6 h, and the atmosphere is a nitrogen atmosphere; after that, the aluminum element in the aluminum-magnesium alloy is removed through alkali leaching to obtain a nickel-cobalt amorphous electrode. The alkali solution required for alkali leaching treatment is a 40 wt% potassium hydroxide solution, the treatment temperature is 100 °C, the treatment duration is 3 h, and 5 wt% potassium sodium tartrate is added to the solution as a corrosion inhibitor, and finally an electrode loaded with an amorphous catalyst is obtained.

[0117] Example 16

[0118] Preparation method of an electrode loaded with an amorphous catalyst:

[0119] The difference between this example and Example 1 lies only in that a 46-mesh twill-woven nickel mesh is used instead of nickel felt as the metallic nickel substrate.

[0120] Comparative Example 1

[0121] Preparation method of an electrode:

[0122] The difference between this comparative example and Example 1 lies only in that steps (1) and (2) are not carried out, but the mixed amorphous powder is directly sprayed on one side surface of the metallic nickel substrate by high-pressure cold spraying and heat-treated to obtain an electrode provided with only an amorphous catalyst layer.

[0123] Comparative Example 2

[0124] Preparation method of an electrode:

[0125] The difference between this comparative example and Example 1 lies only in that step (2) is not carried out, but the mixed aluminum-magnesium powder is directly coated on one side surface of the metallic nickel substrate and sintered at 500 °C to obtain an aluminum-magnesium alloy transition layer, and finally an electrode loaded with an amorphous catalyst is obtained.

[0126] That is, the alloy transition layer is not prepared by plasma spraying, but by coating and then sintering.

[0127] Comparative Example 3

[0128] Preparation method of an electrode:

[0129] The difference between this comparative example and Example 1 lies only in that cobalt chloride is not added in step (3). That is, there is no second amorphous metal source in the amorphous metal source.

[0130] Comparative Example 4

[0131] A preparation method of an electrode:

[0132] The difference between this comparative example and Example 1 is only that: in step (3), the dosage of cobalt chloride is changed to 75 g, and the dosage of nickel chloride is changed to 25 g.

[0133] At this time, the weight ratio of the first amorphous metal source to the second amorphous metal source is 1:3.

[0134] Comparative Example 5

[0135] A preparation method of an electrode:

[0136] The difference between this comparative example and Example 1 is only that: step (4) is not carried out, but the mixed amorphous powder is directly coated on the surface of the aluminum-magnesium alloy transition layer away from the metal nickel substrate, and sintered at 400 °C to obtain an amorphous catalyst layer, and finally an electrode loaded with the amorphous catalyst is obtained.

[0137] That is, the amorphous catalyst layer is not prepared by cold spraying, but by sintering after coating.

[0138] Comparative Example 6

[0139] A preparation method of an electrode:

[0140] The difference between this comparative example and Example 1 is only that: step (5) is not carried out, but the first electrode is directly used as the finally obtained electrode loaded with the amorphous catalyst.

[0141] Testing method

[0142] Alkaline electrolyzed water system: A cuboid with a length of 1.5 cm and a width of 1 cm is cut from each of the electrodes obtained in the examples and comparative examples, and after being fixed with an electrode clamp, it is used as the working electrode for the oxygen evolution reaction (OER) in the alkaline electrolyte. In a three-electrode test system, a platinum wire is used as the counter electrode, and a mercury / mercuric oxide electrode is used as the reference electrode. The effective area of the working electrode immersed in the electrolyte is 1 cm 2 , and 1 mol / L potassium hydroxide is selected as the electrolyte for the test system. During the test, electrochemical data are tested by linear voltammetry scanning and AC impedance method. The rate of linear voltammetry scanning is 5 mV / s, the test potential of AC impedance is 1.53 V (vs. RHE), the AC amplitude is 10 mV, and the frequency range is 106~10 -1 Hz, and the overpotential of each electrode at a current density of 100 mA / cm 2 is obtained. The smaller the value, the faster the charge transfer between the electrode interface and the electrolyte, that is, the higher the oxygen evolution catalytic activity is shown. At the same time, an electrode prepared by spraying commercial IrO2 on nickel foam is provided as a control.

[0143] Anion exchange membrane electrolyzed water system: The electrodes obtained in each of the examples and comparative examples were directly used as self-supporting electrodes for the cathode and anode gas diffusion layers of an anion exchange membrane (AEM) electrolytic cell. The AEM selected was the commercial membrane FAA-3-50. During the test, the electrode clamps of the electrochemical workstation were respectively clamped onto the anode and cathode of the electrolytic cell, and 1M KOH solution was circulated at a flow rate of 100 ml / min. The heating device was turned on and the temperature was set at 60 °C. The cell voltage of each sample was obtained when the electrolyzed water test reached a current density of 2.5 A / cm 2 This cell voltage represents the hydrogen production voltage value of a single electrolysis unit when reaching a certain current density. Therefore, the lower this value is, the lower the energy consumption at the current density and the higher the economic efficiency of the hydrogen production reaction. At the same time, a membrane electrode made of commercial IrO2 was provided as a control.

[0144] The above test results are shown in Table 1.

[0145] Table 1

[0146]

[0147]

[0148] From the above description, it can be seen that the above embodiments of the present invention achieve a tight combination between the amorphous catalyst and the electrode. The obtained electrode loaded with the amorphous catalyst has excellent catalytic activity and stability, and shows high HER and OER catalytic activities in both the alkaline electrolyzed water system and the AEM electrolyzed water system.

[0149] Specifically, compared with Example 1: Example 2 has higher activity, which is attributed to the fact that the material will transform into nickel-iron hydroxyoxide active components during OER, being more conducive to the OER reaction kinetics process compared with the nickel-cobalt catalytic system; in Example 3, a quaternary catalyst was prepared, and the addition of more metal elements enhanced the long-range disorder of the material, with the amorphous characteristics of the material being more significant and the catalytic activity being higher; in Example 4, a noble metal amorphous material was synthesized based on noble metal salts, demonstrating the expandability of this synthesis method, but the platinum-based catalyst has high hydrogen evolution activity and is slightly inferior in terms of oxygen evolution performance; Example 5 is a quaternary catalyst system, with performance superior to that of Example 1, but slightly more iron element is added, which will transform into iron hydroxyoxide with poor conductivity during OER, so the performance is slightly worse than that of Example 3; in Example 6, the content of magnesium in the aluminum-magnesium transition coating was increased, but the corresponding decrease in the content of pore-forming aluminum would lead to a slight decrease in the porosity of the cost electrode coating, affecting the mass transfer process in the electrochemical reaction; in Example 7, the content of aluminum in the aluminum-magnesium transition coating was increased, and the increase in the content of pore-forming aluminum would lead to a decrease in the strength of the porous structure of the coating and an increase in the proportion of collapsed or closed pores in the pore structure, also affecting the mass transfer process in the electrochemical reaction; in Example 8, low power was used for the cladding of the aluminum-magnesium alloy, resulting in weak bonding force between the coating and the substrate, easy detachment of the catalyst, and limited electron transfer between the catalyst and the substrate, leading to performance degradation; in Example 9, high power and fast powder feeding were used for the coating cladding, and the molten aluminum-magnesium alloy quickly filled the pore structure of the substrate, resulting in a reduction in the catalytic active area and hindered gas overflow, so the performance decreased significantly; in Example 10, increasing the amount of sodium borohydride and prolonging the ball milling time would lead to an increase in the crystallinity of the multi-component transition metal catalyst and a decrease in performance due to the weakening of the amorphous characteristics; in Example 11, reducing the amount of sodium borohydride and prolonging the ball milling time would lead to incomplete reduction of the multi-metal salts, and the finally formed amorphous catalytic material would have poor structural integrity, so the performance was poor; in Example 12, the cold spraying pressure and temperature were relatively low, resulting in weak bonding force between the amorphous material and the aluminum-magnesium alloy coating, low structural strength of the amorphous coating, and easy detachment, leading to performance degradation; in Example 13, the cold spraying pressure and temperature were relatively high, and the crystallinity of the amorphous material increased during spraying, and sinterable agglomeration occurred in the coating, so the performance decreased significantly; in Example 14, the thermal annealing temperature was insufficient and the concentration of potassium hydroxide was too low, resulting in incomplete stress relief and incomplete removal of the pore-forming agent aluminum, and the performance decreased; in Example 15, the annealing temperature was too high and the time was too long, resulting in an increase in the crystallization degree of the material; in Example 16, after replacing the substrate with a twill woven nickel mesh, a highly active amorphous coating could still be synthesized on the surface.

[0150] Comparing with the above embodiments: when the low-melting-point aluminum-magnesium coating is not cladded on the substrate surface in Comparative Example 1, the amorphous material cannot form a good bond with the substrate through cold spraying, and the coating is prone to peeling off, resulting in a significant reduction in catalytic performance; in Comparative Example 2, the strength of the aluminum-magnesium transition coating constructed by the calcination method and the substrate is low, and it fails to play a role in connecting the amorphous coating and the substrate; in Comparative Example 3, without the addition of the second metal source, the electronic structure and the degree of amorphization of cobalt cannot be effectively regulated, and the catalytic performance is low; in Comparative Example 4, the atomic ratio of different metals deviates from the preferred ratio, resulting in a performance decline; in Comparative Example 5, the calcination increases the overall crystallinity of the amorphous material, weakens the catalytic characteristics of the amorphous material, and thus the catalytic activity decreases; in Comparative Example 6, the aluminum-magnesium alloy coating alone does not have OER catalytic performance and cannot be directly used as an electrode.

[0151] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those described herein.

[0152] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing an electrode loaded with an amorphous catalyst, characterized in that, Including: Step S1: First mix aluminum metal powder and magnesium metal powder to obtain mixed aluminum-magnesium powder; Step S2: By means of vacuum plasma spraying, spray the mixed aluminum-magnesium powder on at least one surface of a metallic nickel substrate to obtain the metallic nickel substrate loaded with an aluminum-magnesium alloy transition layer; Step S3: Second mix an amorphous metal source and an auxiliary agent to obtain mixed amorphous powder; The auxiliary agent is selected from one or more of sodium borohydride, thiourea, and sodium hypophosphite; Step S4: By means of cold spraying, spray the mixed amorphous powder on one surface of the aluminum-magnesium alloy transition layer away from the metallic nickel substrate to obtain an amorphous catalyst layer, and further obtain a first electrode; Step S5: Heat-treat and alkali-leach the first electrode in sequence to obtain the electrode loaded with the amorphous catalyst; The temperature of the heat treatment is 250°C to 350°C, the time is 0.5 to 5 h, and the atmosphere used is selected from one or more of air atmosphere, vacuum atmosphere, nitrogen atmosphere, argon atmosphere, hydrogen atmosphere, and helium atmosphere; The amorphous metal source includes a first amorphous metal source and a second amorphous metal source, and the weight ratio of the first amorphous metal source to the second amorphous metal source is 1:(1 to 2.5); The first amorphous metal source is a nickel source, and the second amorphous source is one or more of a noble metal source and / or a transition metal source other than the nickel source.

2. The preparation method of the electrode loaded with the amorphous catalyst according to claim 1, characterized in that, The second amorphous source is one or more of metal sources with atomic numbers from 22 to 30 other than the nickel source.

3. The preparation method of the electrode loaded with the amorphous catalyst according to claim 2, characterized in that, The second amorphous metal source is selected from one or more of a cobalt metal source, an iron metal source, and a copper metal source.

4. The preparation method of the electrode loaded with the amorphous catalyst according to claim 2, characterized in that, The second amorphous metal source is a cobalt metal source, an iron metal source, and a copper metal source, and the weight ratio of the cobalt metal source, the iron metal source, and the copper metal source is 1:(0.4 to 0.6):

1.

5. The preparation method of the electrode loaded with the amorphous catalyst according to claim 2, characterized in that, The first amorphous metal source and the second amorphous metal source are each independently in the form of one or several of nitrates, sulfates, acetates, acetylacetonates, and chlorides.

6. The method for preparing an electrode loaded with an amorphous catalyst according to any one of claims 1 to 5, characterized in that, In step S1, The weight ratio of the aluminum metal powder to the magnesium metal powder is 1:(0.1 to 10).

7. The preparation method of the electrode loaded with the amorphous catalyst according to claim 6, characterized in that, The weight ratio of the aluminum metal powder to the magnesium metal powder is 1:(1 to 2).

8. The preparation method of the electrode loaded with the amorphous catalyst according to claim 6, characterized in that, The mesh numbers of the aluminum metal powder and the magnesium metal powder are each independently 100 mesh to 500 mesh.

9. The preparation method of the electrode loaded with the amorphous catalyst according to claim 6, characterized in that, The mode of the first mixing is ball milling, and the rotation speed of the ball milling is 150 r / min to 500 r / min, the time is 0.5 h to 10 h, and the ball milling beads are zirconia beads with a diameter of 10 mm to 30 mm.

10. The method for preparing an electrode loaded with an amorphous catalyst according to claim 9, characterized in that, The dispersion liquid used for the ball milling is ethanol, and the weight ratio of the ethanol to the sum of the weights of the aluminum metal powder and the magnesium metal powder is 1:(6 to 12).

11. The method for preparing an electrode loaded with an amorphous catalyst according to any one of claims 1 to 5, characterized in that, In step S2, The power of the vacuum plasma spraying is 20 kW to 25 kW, the powder feeding rate is 10 g / min to 100 g / min, the distance between the spray head and the metallic nickel substrate is 25 cm to 80 cm, and the moving rate of the spray gun is 50 cm / s to 80 cm / s.

12. The preparation method of the electrode loaded with the amorphous catalyst according to claim 11, characterized in that, In the vacuum plasma spraying, the process gas for generating plasma is a H2 / Ar mixture gas, and the total flow rate of the H2 / Ar mixture gas is 8 L / min to 15 L / min.

13. The preparation method of the electrode loaded with the amorphous catalyst according to claim 12, characterized in that, In the H2 / Ar mixture gas, the volume ratio of H2 to Ar is 1:(2 to 10).

14. The method for preparing an electrode loaded with an amorphous catalyst according to any one of claims 1 to 5, characterized in that, In step S3, The molar ratio of the amorphous metal source to the auxiliary agent is (0.2 to 10):

1.

15. The method for preparing an electrode loaded with an amorphous catalyst according to claim 14, characterized in that, The molar ratio of the amorphous metal source to the auxiliary agent is (2.0 to 6.0):

1.

16. The method for preparing an electrode loaded with an amorphous catalyst according to claim 14, characterized in that, The auxiliary agent is sodium borohydride.

17. The method for preparing an electrode loaded with an amorphous catalyst according to claim 14, characterized in that, The second mixing method is ball milling, and the rotation speed of the ball milling is 150 r / min to 500 r / min, the time is 0.5 h to 10 h, and the ball milling beads are zirconium beads with a diameter of 10 mm to 30 mm.

18. The preparation method of the electrode loaded with the amorphous catalyst according to claim 17, characterized in that, The dispersion liquid used for the ball milling is ethanol, and the weight ratio of the ethanol to the total weight of the amorphous metal source and the auxiliary agent is 1:(4 to 8).

19. The method for preparing an electrode loaded with an amorphous catalyst according to any one of claims 1 to 5, characterized in that, In step S4, The pressure of the cold spraying is 1 MPa to 10 MPa, the temperature is 400 °C to 600 °C, the distance between the nozzle and the aluminum-magnesium alloy transition layer is 10 cm to 60 cm, the powder feeding rate is 10 g / min to 100 g / min, and the moving rate of the spray gun is 20 cm / s to 60 cm / s.

20. The preparation method of the electrode loaded with the amorphous catalyst according to claim 19, characterized in that, The propelling gas used for the cold spraying is a N2 / He mixture gas, and in the N2 / He mixture gas, the volume ratio of N2 to He is 1:(0.1 to 10).

21. The method for preparing an electrode loaded with an amorphous catalyst according to claim 20, characterized in that, In the N2 / He mixture gas, the volume ratio of N2 to He is 1:(4 to 5).

22. The preparation method of the electrode loaded with the amorphous catalyst according to any one of claims 1 to 5, characterized in that, In step S5, The mass concentration of the alkali solution used for the alkali immersion is 10 wt% to 30 wt%, and the alkali immersion is carried out at 25 °C to 80 °C for 6 h to 24 h.

23. An electrode loaded with an amorphous catalyst, comprising a metallic nickel substrate, characterized in that, The electrode loaded with the amorphous catalyst is prepared by the preparation method of the electrode loaded with the amorphous catalyst according to any one of claims 1 to 22.

24. The electrode loaded with the amorphous catalyst according to claim 23, characterized in that, The electrode loaded with the amorphous catalyst further includes an alloy transition layer and an amorphous catalyst layer loaded on at least one surface of the metal nickel substrate, and the alloy transition layer is arranged in contact with the metal nickel substrate, and the amorphous catalyst layer is arranged on the surface of the alloy transition layer far from the metal nickel substrate.

25. The electrode loaded with the amorphous catalyst according to claim 24, characterized in that, The thickness of the amorphous catalyst layer is 10 μm to 150 μm.

26. The electrode loaded with the amorphous catalyst according to claim 24, wherein, The thickness of the amorphous catalyst layer is 40 μm to 50 μm.

27. Use of an electrode loaded with an amorphous catalyst as described in any one of claims 23 to 26 as an electrode in a water electrolysis hydrogen production system, characterized in that, The electrolytic water hydrogen production system is an alkaline electrolytic water system or an anion exchange membrane electrolytic water system.

28. According to the application described in claim 27, wherein, The electrolytic water hydrogen production system is the alkaline electrolytic water system, and the electrode loaded with the amorphous catalyst serves as an oxygen evolution working electrode and / or a hydrogen evolution working electrode in the alkaline electrolytic water system; And / or, The electrolytic water hydrogen production system is the anion exchange membrane electrolytic water system, and the electrode loaded with the amorphous catalyst serves as a self-supporting oxygen evolution electrode and / or a self-supporting hydrogen evolution electrode in the anion exchange membrane electrolytic water system.

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