Preparation method of entropy-based oxide catalyst with high metallicity and application of entropy-based oxide catalyst in hydrogen production by acidic electrolysis of water

Abstract

The invention discloses a preparation method of a high-metallicity entropy-based oxide catalyst and application of the high-metallicity entropy-based oxide catalyst in hydrogen production by acidic electrolyzed water, and belongs to the field of catalysis. Zinc oxide serves as a carrier, a sodium borohydride solution serves as a reducing agent, water-soluble salt at least containing Ru, Ir and A is evenly mixed under the water bath stirring condition, hydrolysis and reduction are conducted, then medium-entropy alloy black powder is formed through suction filtration, washing and drying, finally, rapid incomplete oxidation is conducted in the air atmosphere of 300-500 DEG C, then acid pickling, suction filtration, washing and drying are conducted, and the medium-entropy alloy black powder is obtained. And the entropy-based oxide catalyst with high metallicity is prepared. The catalyst contains a large number of Ir-Ir metallic bonds or / and Ir-Ru metallic bonds, and the proportion of the Ir-Ir metallic bonds or / and the Ir-Ru metallic bonds can reach 30%-40%. Serious lattice distortion is caused by mismatching of a metal atom fingerprint structure and a metal-oxygen atom coordination structure, stress-strain imbalance distribution is induced, and acidic oxygen evolution reaction kinetics is promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy materials for producing hydrogen by acidic water electrolysis, and specifically relates to a method for synthesizing a highly conductive metallic entropy-based oxide catalyst and its application as a high-efficiency oxygen evolution catalyst in the field of producing hydrogen by acidic water electrolysis. Background Art

[0002] With the continuous growth of global energy demand and the increasingly severe environmental problems, the search for renewable energy has become an important issue in today's society. Among the many renewable energy technologies, hydrogen energy has attracted much attention due to its advantages of cleanliness, high efficiency, and high energy storage density. Water electrolysis to produce green hydrogen is an important method for hydrogen production, in which the oxygen evolution reaction (OER) is its key step. However, due to the slow kinetics of OER, an efficient catalyst is required to accelerate the reaction rate. At present, metal ruthenium (Ru) or metal iridium (Ir) based oxides are the most suitable catalysts for OER, especially medium and high entropy oxides (entropy-based oxides) based on Ru or Ir components. Due to their unique structural characteristics and physicochemical properties, such as component cocktail effects, lattice distortion effects and other characteristics, such oxides are endowed with higher electrocatalytic performance, but poor electrical conductivity, which seriously limits their application. In order to solve such common problems, the present invention proposes a strategy of controllable thermal oxidation of RuIr-based alloys to optimize the structure and properties of the oxidation products and prepare highly conductive entropy-based oxides. During the oxidation of Ru or Ir components, Ru can be oxidized to RuO2 at a relatively low temperature (about 300°C), and the energy required for the oxidation process is relatively low. However, the oxidation process of Ir is more complicated, requiring a higher temperature (about 800°C) and energy to form IrO2. Among them, since the Ir (100) and Ir (111) crystal planes are relatively easy to oxidize, and the Ir (110) crystal plane exhibits higher oxidation resistance due to its unique atomic arrangement and higher surface energy, the oxidation-resistant Ir crystal plane is retained during the oxidation process. Therefore, by utilizing the different oxidation abilities of the two metals, metallic RuIr-based oxides that retain a portion of the metal bonds can be obtained by regulating the oxidation temperature to achieve the preparation of new acidic water electrolysis catalysts. Metallic entropy-based oxides combine the properties of metals and oxides, showing the characteristics of high metallicity, high lattice distortion, and high conductivity. This structural inhomogeneity can adjust the band structure, produce more active sites, and help improve catalytic performance. In addition, conductivity has a direct impact on electrocatalytic activity. Highly conductive materials can transfer electrons more quickly, reduce charge accumulation and resistance loss, and maintain stable performance under high current density and long-term operation to avoid structural changes or degradation, which may lead to catalyst deactivation. It can be seen that metallic entropy-based oxides, as a new generation of high-performance water electrolysis catalysts, are of great significance for promoting the large-scale commercial application of acidic water electrolysis to produce hydrogen. Summary of the invention

[0003] The object of the present invention is to provide a method for preparing a high-metallic entropy oxide catalyst containing a large number of metal bonds with high electrocatalytic activity and stability and its application in the production of hydrogen by acidic water electrolysis. Preferably, the high-metallic entropy-based oxide catalyst RuIrAO2 containing the metal bond Ir-Ru / Ir, A=one or more of Mn and Co, RuIrAO2 is RuIrMnO2, RuIrCoO2, and the high-metallic entropy-based oxide catalyst can also include other metal elements such as Y, Cr and other corresponding high-metallic entropy-based oxide catalysts RuIrMnYO2, the metal bond ratio in the high-metallic entropy-based oxide catalyst can reach 30%-40%, the catalyst has a large number of atomic-level short-range ordered metallic atomic network structures, and the conductivity of the high-metallic entropy-based oxide reaches 1.92×10 -7 Ω·m, close to the conductivity of graphite or metal, can be used in the production of hydrogen in acidic water electrolysis. 10mA cm in the anode oxygen precipitation reaction in acidic environment -2 The metallic entropy-based oxide catalyst RuIrMnO2 can be used at 50 mA cm-1 to achieve ultra-low overpotential of 212 mV at low current density, which is much lower than the 277 mV of commercial IrO2 catalyst. -2 The device operated for 170 h at a low and unchangeable cell potential (1.69 V), which far exceeds the commercial IrO2||Pt / C component (20 h).

[0004] The present invention relates to a method for preparing an entropy-based oxide catalyst with high metallicity and its application in the field of acidic water electrolysis. First, zinc oxide is used as a carrier and sodium borohydride (NaBH4) solution is used as a reducing agent. Under water bath stirring conditions, multiple metal water-soluble salts containing at least Ru, Ir, and A are mixed uniformly and hydrolyzed and reduced. Then, medium-entropy alloy black powder is formed by suction filtration, washing, and drying. Finally, rapid incomplete oxidation is carried out in an air atmosphere of 300-500°C, preferably 350°C. Then, acid washing, suction filtration, washing, and drying are carried out to prepare an entropy-based oxide catalyst with high metallicity for the first time. The high metallic entropy-based oxide catalyst contains a large amount of Ir-Ir metal bonds or / and Ir-Ru metal bonds in the catalyst, which can account for 30%-40%, and has a large number of atomic-level short-range ordered metallic atomic network structures. The entropy-based oxide catalyst is a nanoparticle with a crystal structure, and the crystal structure is a stable rutile configuration oxide nanoparticle; the particle size is about 3-9nm.

[0005] The present invention also protects a method for preparing the highly metallic entropy-based alloy catalyst, comprising the following steps:

[0006] (1) dispersing the zinc oxide carrier in deionized water and forming a uniform milky white slurry by ultrasonic treatment;

[0007] (2) dissolving at least a Ru source solution, an Ir source solution and an A source solution precursor in the slurry, and performing ultrasonic treatment to obtain a uniform metal salt mixed solution;

[0008] (3) adding a NaBH4 reducing agent solution dropwise to the above-mentioned metal salt mixed solution under stirring conditions in a water bath (e.g., 40-80°C, preferably 60°C) to induce precipitation of the metal salt; then, filtering and separating the obtained solid, washing with deionized water to remove residual impurities, and drying in an oven at 60-80°C to obtain uniformly dispersed ruthenium-iridium-manganese alloy nanoparticles with distinct particle sizes.

[0009] (4) Preparation of high metallic entropy-based oxide powder containing a large number of metal bonds: The ruthenium-iridium-manganese entropy-based alloy particles dried in step (3) are placed in a tube furnace for rapid incomplete oxidation transformation, i.e., the temperature is raised to a certain temperature at a certain heating rate in a certain atmosphere, kept at this temperature for a certain period of time, and then naturally cooled to room temperature in the tube furnace; then, the particles are pickled in a sulfuric acid solution of a certain concentration, and filtered, washed, and dried to obtain a high metallic entropy-based oxide catalyst powder having a large number of Ir-Ir or / and Ir-Ru metal bonds.

[0010] In a preferred embodiment of the present invention, the size of the nanoparticles is controlled by adjusting the ratio of the feed amount of the metal salt precursor to the zinc oxide carrier. Generally, every 20 mg of zinc oxide corresponds to a total molar amount of 0.05-0.5 mmol of the metal salt. At the same time, the uniform distribution of the alloy nanoparticles can be ensured by precisely controlling the dripping speed of the NaBH4 reducing agent solution.

[0011] In a preferred embodiment of the present invention, the Ru source, Ir source and A source in the precursor solution are anions of soluble Ru salt, soluble Ir salt and soluble A salt, selected from one or more of acetate ion, chloride ion and sulfate ion.

[0012] In a preferred embodiment of the present invention, the Ru source, Ir source and A source are ruthenium trichloride, chloroiridic acid and manganese chloride or cobalt chloride, and the molar percentage of the metal elements is calculated as follows: Ru: 35%-45at%; Ir: 25%-35at%; A: 25%-35at%, and the molar ratio of ruthenium trichloride, chloroiridic acid and chloride of A is 6:4:(2-6). Every 20 mg of zinc oxide carrier corresponds to 20-30 ml of deionized water.

[0013] In a preferred embodiment of the present invention, the sodium borohydride reduction reaction temperature in step (3), i.e., the water bath temperature, is 55-80°C, preferably 60°C.

[0014] In a preferred embodiment of the present invention, the molar amount of sodium borohydride used in step (3) is 5-10 times the molar amount of the total metal elements fed.

[0015] In a preferred embodiment of the present invention, the rapid incomplete oxidation transformation temperature in step (3) is 300-500°C, preferably 350°C.

[0016] In a preferred embodiment of the present invention, the rapid incomplete oxidation heating rate in step (4) is 5-10°C / min, preferably 5°C / min.

[0017] In a preferred embodiment of the present invention, in step (4), the atmosphere for the rapid incomplete oxidation conversion is air.

[0018] In a preferred embodiment of the present invention, in step (4), the holding time of the rapid incomplete oxidation transformation is 0.5-1.5 h, preferably 1 h.

[0019] In a preferred embodiment of the present invention, in step (4), the pickling concentration is 0.5-2M H + The proton concentration is preferably 1M.

[0020] In a preferred embodiment of the present invention, in step (4), the liquid used for pickling can be sulfuric acid, hydrochloric acid, nitric acid, etc., preferably sulfuric acid.

[0021] In a preferred embodiment of the present invention, in step (4), the pickling time is 0.5-1.5 h, preferably 1 h.

[0022] Further, the precursors added in step (2) are Ru source, Ir source and A source, and the corresponding metallic entropy-based oxide catalyst RuIrAO2 is obtained; the precursor of step (2) may also include other metal element B source materials, and the corresponding metallic entropy-based oxide catalyst RuIrABO2 is obtained, and the other metal element B is selected from Y, Cr, etc., and the corresponding other metal element B source materials are sulfates, chlorides, etc. of B; the molar ratio of B to A is 0-2:1, and more preferably 0-1:1.

[0023] The invention discloses an application of the high metallic entropy-based oxide catalyst in the production of hydrogen by acidic water electrolysis. The mismatch between the metal bond and the oxide structure in the high metallic entropy-based oxide catalyst leads to severe lattice distortion, induces an unbalanced distribution of stress and strain, and promotes the kinetics of the acidic oxygen evolution reaction. The catalyst has high conductivity, a large number of atomic-level short-range ordered metallic atomic network structures, and a resistivity of 1.92×10 -7 Ω·m, close to the conductivity of graphite or metal.

[0024] The present invention can break the common seesaw relationship between activity and stability in the acidic OER water splitting process by controlling the relative content of metal bonds in high metallic entropy-based oxide catalysts. This technical solution is simple and controllable, opens a door for the design and development of advanced catalysts, provides feasibility for large-scale industrial applications, and demonstrates its broad prospects and economic value in practical applications.

[0025] The metal bonds such as Ir-Ir / Ru in the high-metallic entropy-based oxide prepared by the present invention and the short-range ordered metal-state atomic network structure activate the asymmetric metal-oxygen chemical bond to promote the kinetics of the acidic oxygen precipitation reaction. At the same time, because it contains a certain degree of metal bonds, the conductivity of the catalyst is enhanced, which is conducive to electron transfer and participation in chemical reactions, and further improves the activity. In addition, the short-range ordered metal-state atomic network structure slows down the dissolution process of Ru and Ir, inhibits the escape of lattice oxygen, slows down electrochemical corrosion, and thus ensures long-term stability. The formation enthalpy and binding energy of the corresponding oxide are further reduced, ensuring the structural stability of the metal-oxygen and metal-metal chemical bonds, and achieving the durability of the catalyst.

[0026] The present invention adopts a two-step synthesis method, which is easy to operate, highly practical, and has large-scale production capabilities. The entropy-based oxide RuIrMnO2 containing Ir-Ir / Ru metal bonds and metallic atomic network structures can be used in the field of efficient acidic water electrolysis to produce hydrogen. It has better electrocatalytic activity than commercial iridium dioxide and has higher stability under high current density conditions. Compared with existing water electrolysis catalysts, the entropy-based oxide catalyst with high metallicity has a higher electrocatalytic activity than commercial iridium dioxide in the anodic oxygen precipitation reaction in an acidic environment. -2 The ultra-low overpotential of 212 mV is shown at a low current density, which is much lower than the 277 mV of commercial IrO2 catalysts. For PEMWE devices, metallic entropy-based oxide catalysts such as RuIrMnO2 can be used at 50 mA cm -2 The device operated for 170 h at a low and unchangeable cell potential (1.69 V), which far exceeds the commercial IrO2||Pt / C component (20 h). BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the accompanying drawings. The accompanying drawings are only used to schematically illustrate and explain the present invention and do not limit the scope of the present invention.

[0028] Figure 1 It is the transmission electron microscope (TEM) image and particle size distribution diagram of the ruthenium-iridium-manganese alloy nanoparticles obtained in Example 1.

[0029] Figure 2 This is a transmission electron microscope (TEM) image of the highly metallic entropy-based ruthenium iridium manganese oxide obtained in Example 1.

[0030] Figure 3 It is the X-ray diffraction (XRD) pattern of the ruthenium-iridium-manganese alloy in Example 1 and the ruthenium-iridium-manganese oxide catalyst with high metallic entropy.

[0031] Figure 4 It is the high-resolution XPS spectra of Ru 3p and Ir 4f in the ruthenium-iridium-manganese alloy and the ruthenium-iridium-manganese oxide catalyst with high metallicity in Example 1.

[0032] Figure 5 The polarization curves of the high metallic entropy-based oxide catalysts and commercial IrO2 prepared in Examples 1, 2, and 3 and the -2 , 50mA cm -2 and 100mA cm -2 Overpotential bar graph at current density. The tested electrolyte is 0.5M H2SO4; the scan rate is 10mV s -1 ; The scanning voltage range is 0.525-0.9V.

[0033] Figure 6 It is the X-ray diffraction (XRD) spectrum of the gold high entropy-based oxide RuIrMnO2 catalyst before and after the constant current test in Example 1.

[0034] Figure 7 The chronopotentiometry curves (current density 50 mA cm) of the PEMWE cell assembled with the catalyst obtained in Example 1 and commercial IrO2 as the anode catalyst and commercial Pt / C (40 wt% Pt) as the cathode catalyst in 0.5 M H2SO4 -2 ).

[0035] Figure 8 The distribution of Ru and Ir valence states of the gold high-entropy-based oxide RuIrMnO2 catalyst in Example 1, where Ru 0 Accounting for 32.4%, Ir 0 It accounts for 44.7%, indicating that some metals exist in a zero-valent state, which is an Ir-Ir / Ru bond. DETAILED DESCRIPTION

[0036] The present invention is described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited by the specific embodiments.

[0037] Embodiment 1:

[0038] Highly metallic entropy-based RuIrMnO2 catalyst

[0039] (1) 20 mg of zinc oxide was ultrasonically dispersed in 20 mL of aqueous solution to form a milky white slurry. 0.75 mL of 0.1 M RuCl3, 0.5 mL of 0.1 M H2IrCl6 and 0.5 mL of 0.1 M MnCl2 metal salt solution were dissolved in the above slurry and ultrasonicated for 30 min.

[0040] (2) 35 mg of NaBH4 was completely dissolved in 10 mL of deionized water, and then gradually added dropwise to the mixed solution in step (1) under stirring at 60° C. over 30 min to produce a precipitate. The obtained solid powder was separated from the solution by a suction filtration device, rinsed with a large amount of deionized water to remove the residue, and dried in an oven at 60° C. for 12 h.

[0041] (3) Place the dried sample in step 2 into a porcelain boat and incubate it in air at 5°C min -1 The heating rate was raised to 350°C, kept at this temperature for 1 hour, cooled, and acidified in a 0.5M H2SO4 solution for 1 hour, and finally filtered, washed, and dried to obtain the RuIrMnO2 catalyst, a high metallic entropy-based oxide prepared by rapid incomplete thermal oxidation. For the oxides obtained by rapid incomplete oxidation, the valence state distribution in the high metallic entropy-based oxides can be obtained by performing X-ray photoelectron spectroscopy (XPS) tests on typical ruthenium iridium manganese oxides and processing the data using Avantage software.

[0042] Example 2

[0043] Highly metallic entropy-based RuIrCoO2 catalyst

[0044] (1) 20 mg of zinc oxide was ultrasonically dispersed in 20 mL of aqueous solution to form a milky white slurry. 0.75 mL of 0.1 M RuCl3, 0.5 mL of 0.1 M H2IrCl6 and 0.5 mL of 0.1 M CoCl2 metal salt solution were dissolved in the above slurry and ultrasonicated for 30 min.

[0045] (2) 35 mg of NaBH4 was completely dissolved in 10 mL of deionized water, and then gradually added dropwise to the mixed solution in step (1) under stirring at 60° C. over 30 min to produce a precipitate. The obtained solid powder was separated from the solution by a suction filtration device, rinsed with a large amount of deionized water to remove the residue, and dried in an oven at 60° C. for 12 h.

[0046] (3) Place the dried sample in step 2 into a porcelain boat and incubate it in air at 5°C min -1The heating rate was raised to 350°C and kept warm for 1 hour. After cooling, it was acidified in 0.5M H2SO4 solution for 1 hour. Finally, it was filtered, washed and dried to obtain the high metallic entropy-based oxide RuIrCoO2 catalyst prepared by rapid incomplete thermal oxidation.

[0047] Example 3

[0048] Highly metallic entropy-based RuIrMnYO2 catalyst

[0049] (1) 20 mg of zinc oxide was ultrasonically dispersed in 20 mL of aqueous solution to form a milky white slurry, and 0.75 mL of 0.1 M RuCl3, 0.5 mL of 0.1 M H2IrCl6, 0.5 mL of 0.1 M MnCl2 and 0.5 mL of 0.05 M Y2(SO4)3 metal salt solution were dissolved in the above slurry and ultrasonicated for 30 min.

[0050] (2) 35 mg of NaBH4 was completely dissolved in 10 mL of deionized water, and then gradually added dropwise to the mixed solution in step (1) under stirring at 60° C. over 30 min to produce a precipitate. The obtained solid powder was separated from the solution by a suction filtration device, rinsed with a large amount of deionized water to remove the residue, and dried in an oven at 60° C. for 12 h.

[0051] (3) Place the dried sample in step 2 into a porcelain boat and incubate it in air at 5°C min -1 The heating rate was raised to 350°C and kept warm for 1 hour. After cooling, it was acidified in 0.5M H2SO4 solution for 1 hour. Finally, it was filtered, washed and dried to obtain the high metallic entropy-based oxide RuIrMnYO2 catalyst prepared by rapid incomplete thermal oxidation.

[0052] Figure 1 This is a transmission electron microscope (TEM) image of the ruthenium-iridium-manganese alloy nanoparticles obtained in Example 1. The average particle size of the alloy nanoparticles is 2.66 nm, the alloy is evenly distributed, and the particle size is controllable.

[0053] Figure 2 This is a transmission electron microscope (TEM) image of the metallic entropy-based ruthenium-iridium-manganese oxide catalyst obtained in Example 1. The average particle size of the oxide nanoparticles is 7 nm.

[0054] Figure 3 This is the X-ray diffraction pattern (XRD) of the catalyst obtained in Example 1. It can be seen that the peak position is close to the peak position of rutile ruthenium dioxide, indicating that the prepared catalyst has a typical rutile structure.

[0055] Figure 4The high-resolution XPS spectra of Ru 3p and Ir 4f in the ruthenium-iridium-manganese alloy and the partially metallic ruthenium-iridium-manganese oxide catalyst in Example 1. It can be seen that the proportion of metal bonds is 30%-40%, indicating that the prepared oxide catalyst has metallic characteristics.

[0056] Figure 5 The polarization curves of the metallic entropy-based oxide catalysts and commercial IrO2 prepared in Examples 1, 2, and 3 and the -2 , 50mA cm -2 and 100mA cm -2 Overpotential bar graph at current density. The tested electrolyte is 0.5M H2SO4; the scan rate is 10mV s -1 ; The scanning voltage range is 0.525-0.9 V. It can be found that the metallic entropy-based oxide catalyst containing metal bonds prepared by rapid oxidation has a high conductivity at 10 mA cm -2 The overpotentials at different current densities are 212mV, 216mV, and 244mV, which are much lower than the 277mV of commercial IrO2. And it shows even lower overpotential at high current density.

[0057] Figure 6 The X-ray diffraction (XRD) patterns of some metallic oxide RuIrMnO2 catalysts before and after the constant current test in Example 1. It can be found that there is no obvious change in crystallinity of the catalyst before and after the electrochemical test, and it is still a stable rutile structure.

[0058] Figure 7 The chronopotentiometry curves (current density 50 mA cm) of the PEMWE cell assembled with the catalyst obtained in Example 1 and commercial IrO2 as the anode catalyst and commercial Pt / C (40 wt% Pt) as the cathode catalyst in 0.5 M H2SO4 -2 ). After 170 hours of chronopotentiometry, the overpotential rise of the prepared catalyst was negligible, far exceeding that of commercial iridium dioxide (IrO2) catalyst, showing excellent durability.

[0059] Figure 8 The distribution of Ru and Ir valence states of the gold high-entropy-based oxide RuIrMnO2 catalyst in Example 1, where Ru 0 Accounting for 32.4%, Ir 0 It accounts for 44.7%, indicating that some metals exist in a zero-valent state, which is an Ir-Ir / Ru bond.

[0060] The abundant Ir-Ir / Ru metal bonds and the atomically ordered short-range metallic atomic network structure activate the asymmetric metal-oxygen chemical bonds and promote the kinetics of the acidic oxygen evolution reaction. In addition, the conductivity of the high-metallic entropy-based oxides is enhanced, which is conducive to electron transfer and participation in chemical reactions, further improving the activity. More importantly, the metal bond interaction inhibits the release of lattice oxygen and slows down the dissolution process of Ru and Ir, thereby ensuring long-term stability. The preferred high-metallic entropy-based RuIrMnO2 catalyst has a high conductivity at 10 mA cm in 0.5 M H2SO4 medium. -2 The overpotential of oxygen evolution is 212 mV at a current density of 50 mA cm-1, which is much lower than the 277 mV of the commercial IrO2 catalyst. -2 It can run for 170 hours at a low battery potential (1.69V), which far exceeds the commercial IrO2||Pt / C component (20 hours). It can be seen that this technical solution can greatly improve the activity and stability of water electrolysis catalysts by controlling the relative content of metal bonds in metallic entropy-based oxide catalysts. This technical solution is simple and the synthesis is simple and controllable, which opens a door for the design and development of advanced catalysts and provides feasibility for large-scale industrial applications, showing its broad prospects and economic value in practical applications.

[0061] The above specific embodiments describe the basic principles and main features of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and any changes or modifications that are not thought of through creative work should be included in the protection scope of the present invention. Without departing from the scope of the present invention, the present invention will also have various changes and improvements, and these changes and improvements will fall within the scope of the protection required.

Claims

1. A method for preparing a highly metallic entropy-based oxide catalyst, characterized in that: The following steps are involved: First, zinc oxide is used as a carrier and sodium borohydride (NaBH4) solution is used as a reducing agent. Under water bath stirring conditions, a uniformly mixed precursor of multiple metal water-soluble salts containing at least Ru, Ir, and A is added and hydrolyzed and reduced. Then, it is filtered, washed, and dried to form a medium-entropy alloy black powder. Finally, it is rapidly incompletely oxidized in an air atmosphere at 300-500°C, preferably 350°C. Then, it is acid-washed, filtered, washed, and dried to prepare a high-metallic entropy-based oxide catalyst for the first time. The high-metallic entropy-based oxide catalyst contains a large number of Ir-Ir metal bonds or / and Ir-Ru metal bonds. There are a large number of atomic-level short-range ordered metallic atomic network structures inside the catalyst, and the metal atomic network structure does not match the metal-oxygen atom coordination structure, resulting in severe lattice distortion. The conductivity of the high-metallic entropy-based oxide reaches 1.92×10 -7 Ω·m, which is basically similar to the conductivity of graphite.

2. The method for preparing a highly metallic entropy-based oxide catalyst according to claim 1, characterized in that: The metal bond ratio can reach 30%-40%; the entropy-based oxide catalyst is a nanoparticle with a crystal structure, and the crystal structure is a stable rutile-configured oxide nanoparticle; the particle size is about 3-9nm.

3. The method for preparing a highly metallic entropy-based oxide catalyst according to claim 1, characterized in that: The specific steps include: (1) dispersing the zinc oxide carrier in deionized water and forming a uniform milky white slurry by ultrasonic treatment; (2) dissolving at least a Ru source solution, an Ir source solution and an A source solution precursor in the slurry, and performing ultrasonic treatment to obtain a uniform metal salt mixed solution; (3) adding NaBH4 reducing agent solution dropwise to the above metal salt mixed solution under stirring in a water bath to induce precipitation of the metal salt; Subsequently, the solid obtained by separation by suction filtration is washed with deionized water to remove residual impurities, and dried to obtain ruthenium-iridium-manganese alloy nanoparticles with uniform dispersion and distinct particle sizes; (4) Preparation of high metallic entropy-based oxide powder containing a large number of metal bonds. The ruthenium-iridium-manganese entropy-based alloy particles dried in step (3) are placed in a tube furnace for rapid incomplete oxidation transformation, that is, they are heated to a certain temperature at a certain heating rate in a certain atmosphere, kept warm for a certain period of time, and then naturally cooled to room temperature in the tube furnace; then, they are pickled in a sulfuric acid solution of a certain concentration, and filtered, washed, and dried to obtain a high metallic entropy-based oxide catalyst powder having a large number of Ir-Ir or / and Ir-Ru metal bonds.

4. The method according to any one of claims 1 to 3, characterized in that: Every 20 mg of zinc oxide corresponds to a total molar amount of 0.05-0.5 mmol of metal salt; at the same time, by precisely controlling the dripping speed of the NaBH4 reducing agent solution, the uniform distribution of the alloy nanoparticles can be ensured.

5. The method according to any one of claims 1 to 3, characterized in that: The Ru source, Ir source and A source in the precursor solution are anions of soluble Ru salt, soluble Ir salt and soluble A salt, selected from one or more of acetate ion, chloride ion and sulfate ion; Calculated by molar percentage of metal elements: Ru: 35%-45at%; Ir: 25%-35at%; A: 25%-35at%; More preferably, the Ru source, Ir source, and A source are ruthenium trichloride, chloroiridic acid, and manganese chloride or cobalt chloride, and the molar ratio of ruthenium trichloride, chloroiridic acid, and chloride of A is 6:4:(2-6); Every 20 mg of zinc oxide carrier corresponds to 20-30 ml of deionized water.

6. The method according to any one of claims 1 to 3, characterized in that: The temperature of the sodium borohydride reduction reaction, i.e. the water bath temperature, is 55-80°C, preferably 60°C; the molar amount of sodium borohydride used is 5-10 times the molar amount of the total metal element feed amount.

7. The method according to any one of claims 1 to 3, characterized in that: The rapid incomplete oxidation transformation temperature is 300-500°C, preferably 350°C; The rapid incomplete oxidation heating rate is 5-10°C / min, preferably 5°C / min; The atmosphere for the rapid incomplete oxidation transformation is air; The fast incomplete oxidation conversion holding time is 0.5-1.5h, preferably 1h. The pickling concentration is 0.5-2M H + The proton concentration is preferably 1M. The liquid used for pickling can be sulfuric acid, hydrochloric acid, nitric acid, etc., preferably sulfuric acid. The pickling time is 0.5-1.5h, preferably 1h.

8. The method according to any one of claims 1 to 3, characterized in that: The added precursors are Ru source, Ir source and A source, and the corresponding metallic entropy-based oxide catalyst RuIrAO2 is obtained; the precursor of step (2) may also include other metal element B source materials, and the corresponding metallic entropy-based oxide catalyst RuIrABO2 is obtained, and the other metal element B is selected from Y, Cr, etc., and the corresponding other metal element B source materials are sulfates, chlorides, etc. of B; the molar ratio of B to A is 0-2:1, and more preferably 0-1:

1.

9. The high metallic entropy-based oxide catalyst prepared according to any one of claims 1 to 8.

10. Use of a high metallic entropy-based oxide catalyst prepared by the method according to any one of claims 1 to 8 in the production of hydrogen by acidic water electrolysis.

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