A ruthenium oxide catalyst based on modification of acidic oxidizing ligands and its application in acidic oxygen evolution reaction

Abstract

This invention discloses a ruthenium oxide catalyst modified with an acidic oxidizing ligand and its application in the acidic oxygen evolution reaction (OER), belonging to the field of electrocatalytic materials technology. The catalyst comprises a metal oxide matrix and an acidic oxidizing ligand modified on the surface of the metal oxide matrix; the acidic oxidizing ligand is a polyoxometalate; the polyoxometalate is anchored to the surface of the metal oxide matrix through heteroatom-oxygen-metal chemical bonds; the polyoxometalate is selected from one or more of Keggin-type polyoxometalates, Dawson-type polyoxometalates, Waugh-type polyoxometalates, and vacancy-type polyoxometalates. This invention systematically solves the long-standing bottleneck of the activity-stability conflict of ruthenium oxide in acidic OER by using polyoxometalates as functional ligands.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalytic materials technology, and more specifically relates to a ruthenium oxide catalyst based on acidic oxidizing ligand modification and its application in the acidic oxygen evolution reaction. Background Technology

[0002] Faced with the inherent volatility and intermittency of most renewable energy sources, proton exchange membrane electrolysis (PEMWE) technology, with its advantages of rapid dynamic response, high current density, and high hydrogen purity, has become a powerful tool for coupling renewable energy in the future. The trade-off between activity and stability of iridium-based and ruthenium-based oxygen evolution catalysts at the anode has long been a key bottleneck restricting the development of PEMWE. Currently, several types of metal oxides represent the most advanced anode catalyst materials and candidate materials: Iridium oxide (IrO2) has long been considered the only anode catalyst capable of long-term stable operation under industrial-grade strongly acidic conditions. However, its scarcity has hindered the development of anode catalysts for long-term stable operation; even when the iridium noble metal loading in the electrode assembly (MEA) is limited to 0.25 mg Ir / cm³, the situation remains challenging. 2 Large-scale deployment of iridium-based catalysts in PEMWE achieves 1TW H2 The energy conversion still requires the consumption of more than 8,100 tons of metallic iridium, which is more than 400 times the annual production of iridium (<10 tons per year).

[0003] Ruthenium oxide (RuO2) is considered the most promising candidate to replace iridium-based catalysts due to its relatively low cost and higher activity. However, it exhibits severe problems with poor solubility stability; the Faraday efficiency of ruthenium dissolution is approximately 0.1%, more than 100 times that of iridium oxide (IrO2). As a result, the stability of most PEMWE devices assembled using RuO2 as the anode catalyst is still far from achieving the voltage decay rate target of 2.3 μV / h.

[0004] Therefore, improving the stability of ruthenium oxide through modification strategies and overcoming the balance between high activity and relatively low cost is of great significance. Based on this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a ruthenium oxide catalyst based on acidic oxidizing ligand modification and its application in the acidic oxygen evolution reaction, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: One of the technical solutions of the present invention is to provide a ruthenium oxide catalyst based on acidic oxidizing ligand modification, wherein the ruthenium oxide catalyst comprises a metal oxide matrix and an acidic oxidizing ligand modified on the surface of the metal oxide matrix; The acidic oxidizing ligand is a polyoxometalate; The polyoxometalate is anchored to the surface of the metal oxide matrix via heteroatom-oxygen-metal chemical bonds; The polyoxometalate is selected from one or more of Keggin-type polyoxometalates, Dawson-type polyoxometalates, Waugh-type polyoxometalates, and vacancy-type polyoxometalates.

[0007] Preferably, the polyoxometalate includes one or more of silicotungstic acid, phosphotungstic acid, and phosphomolybdic acid.

[0008] The second technical solution of the present invention provides a method for preparing the above-mentioned ruthenium oxide catalyst based on acidic oxidizing ligand modification, comprising the following steps: The ruthenium metal salt precursor was dissolved in an aqueous solution, the pH was adjusted to 6-8, and a precipitate was formed to obtain the ruthenium metal oxide precursor. The metal oxide precursor was dispersed in water, and a polyoxometalate was added. After mixing evenly, a hydrothermal reaction was carried out to obtain the ruthenium oxide catalyst based on acidic oxidizing ligand modification.

[0009] Preferably, an alkaline solution is used to adjust the pH, and the alkaline solution is preferably a potassium hydroxide solution, a sodium hydroxide solution, or ammonia water; after adjusting the pH, the reaction continues for 0.5 to 2 hours.

[0010] Preferably, the mass-to-volume ratio of the polyoxometalate to water in the hydrothermal reaction system is (3~8) mg:14 mL; after adding the polyoxometalate, the mixture is stirred for 0.5~2 h, preferably 1 h.

[0011] Preferably, the hydrothermal reaction is carried out at a temperature of 160~200℃ for a time of 12~48h.

[0012] The third technical solution of the present invention provides the application of the above-mentioned ruthenium oxide catalyst modified with acidic oxidizing ligands in the acidic oxygen evolution reaction.

[0013] The fourth technical solution of the present invention provides an acidic oxygen evolution reaction electrode comprising the above-mentioned ruthenium oxide catalyst modified with acidic oxidizing ligands.

[0014] The technical principle of this invention is as follows: This invention proposes to modify the surface of metal oxides with acidic oxidizing ligands (polyoxometalates (POMs)) to achieve a synergistic improvement in activity and stability, as detailed below: Under strongly acidic and oxidizing electrolytic environments, the electrochemical failure of RuO2 is not caused by a single factor, but rather stems from the vicious coupling of two degradation mechanisms. On the one hand, Ru centers undergo direct demetallization due to over-oxidation at high potentials, generating soluble RuO4, leading to irreversible dissolution of the active component. Simultaneously, the lattice oxygen originally coordinated with Ru is further exposed due to Ru's departure, exacerbating the loss of oxygen components. On the other hand, the oxygen evolution mechanism (LOM) mediated by lattice oxygen is over-excited, causing lattice oxygen to directly participate in the reaction and escape from the bulk phase in large quantities. This results in a sharp increase in Ru coordination unsaturated sites (CUS), which further reduce the coordination stability of Ru and accelerate the demetallization process. The two factors mentioned above form a positive feedback loop of "demetallization-deoxygenation-re-demetallization," ultimately driving the collapse of the RuO2 lattice structure and the continuous dissolution of active species. This is the fundamental reason why RuO2's stability in the acidic oxygen evolution reaction (OER) is far inferior to that of IrO2 (RuO2's Faraday efficiency of dissolution is approximately 0.1%, more than 100 times that of IrO2). Therefore, improving RuO2's stability essentially lies in achieving a balance between electron and lattice oxygen: both by accelerating reaction kinetics and promoting the efficient participation of water molecules in the reaction to replenish electrons and lattice oxygen ("opening up new sources"), and by suppressing the excessive oxidation state of the metal center and the excessive occurrence of the LOM mechanism to slow down the consumption of lattice oxygen and structural degradation ("reducing consumption"). However, in practice, these two aspects are inherently contradictory—accelerated reaction kinetics are often accompanied by higher potentials and stronger oxidizing environments, which are precisely the triggers for metal over-oxidation and the LOM pathway. Therefore, simply strengthening one aspect is unlikely to be effective; a breakthrough must be sought from a global perspective of controlling the interfacial chemical environment and reaction pathways.

[0015] Based on the above, this invention utilizes the unique proton transport characteristics of aqueous systems to provide a method distinct from traditional elemental doping or morphology manipulation. In aqueous systems, H... + Proton transport occurs via a hopping mechanism along hydrogen bonds, where protons do not diffuse but rapidly transition through the coordinated breaking and formation of OH bonds within the hydrogen bond network. Therefore, the connectivity of the hydrogen bond network directly affects the efficiency of proton dissociation and transfer. However, water molecules (H₂O) themselves transfer to the active site via convection and diffusion. While an excessively strong hydrogen bond network facilitates proton transport, it can also hinder H₂O mass transfer and dissociation by enhancing intermolecular forces, thus degrading reactant supply. This contradiction suggests that an ideal catalyst interface should possess a moderately ordered hydrogen bond network structure, ensuring both H₂O and water transport efficiency. +This invention achieves efficient transport without sacrificing the accessibility of H2O. According to the classic hard acid-base (HSAB) theory, hard acids preferentially bind to hard bases. Polyacids (POMs), as a class of nanoscale metal-oxygen clusters with well-defined structures, possess strong acidity, strong oxidizing power, and high negative charge density, making them typical hard acids. H2O, as a hard base, naturally tends to interact with polyacids. This invention modifies the RuO2 surface with polyacids as hard acid ligands, enabling them to act as H2O trapping centers and regulatory nodes in the hydrogen bond network, thereby achieving orderly regulation of water molecule behavior at the catalyst interface.

[0016] The modification with polyacids exerts a synergistic effect at three levels: physical structure, electronic structure, and reaction pathway. At the physical structure level, polyacids, acting as strong binding ligands, are firmly anchored to the RuO2 surface via heteroatom-oxygen-metal chemical bonds such as WO-Ru, effectively stabilizing the metastable surface structure of RuO2, inhibiting excessive reconstruction and migration of surface atoms, and simultaneously inducing a loose and porous morphology in the catalyst, significantly increasing the electrochemical active area and reactant accessibility. At the electronic structure level, due to their strong oxidizing properties, polyacids abstract some electrons from the Ru center, stabilizing the high valence state of Ru and weakening the thermodynamic driving force for further excessive oxidation of Ru, thereby inhibiting the RuO4 formation pathway. Simultaneously, the WO-Ru bonding interface introduces additional electron buffering capacity, allowing for reasonable regulation of the electron cloud density of lattice oxygen, reducing the tendency of lattice oxygen to directly participate in the LOM pathway, and fundamentally slowing down the rate of lattice oxygen loss. At the reaction pathway level, the polyacid-assisted proton transfer mechanism significantly lowers the energy barrier of the OER deprotonation step, making the reaction kinetics more inclined towards the adsorption evolution mechanism (AEM) pathway. That is, H2O molecules first adsorb onto the metal active site, and generate O2 through a series of deprotonation steps. The entire process does not depend on the direct participation of lattice oxygen. This effectively suppresses the over-excitation of the LOM pathway and avoids the large-scale consumption of lattice oxygen as a reactant, achieving efficient "open source and conserve energy" of lattice oxygen and electrons. The above three levels are coupled and mutually supportive: the porosity of the physical structure and the improvement of the interface hydrophilicity enhance the supply and mass transfer of H2O, the regulation of the electronic structure suppresses the instability inducement, and the deflection of the reaction pathway fundamentally avoids the lattice oxygen consumption channel. Together, they solve the originally inseparable relationship between high activity and high potential-strong oxidation-fast degradation.

[0017] In summary, this invention uses polyacids as functional ligands to systematically solve the bottleneck of the long-standing activity-stability conflict of RuO2 in acidic OER.

[0018] The present invention discloses the following technical effects: 1. This invention employs polyoxometalates (POMs) as acidic oxidizing ligands to modify ruthenium oxide catalysts. Utilizing the abundant oxygen atom density and strong hydrophilicity on the POM surface, the hydrogen bond network connectivity at the catalyst interface is effectively controlled. The direct effect is a significant improvement in the proton (H+) exchange rate during the acidic oxygen evolution reaction. + The mass transfer kinetics of water molecules (H2O) and water molecules (H2O) are improved, which lowers the energy barrier of the deprotonation step and thus greatly enhances the intrinsic activity of the catalyst.

[0019] 2. This invention induces a "resource-generating and resource-saving" effect on lattice oxygen through the electronic interaction (WO-Ru bonding) between the polyacid ligand and the ruthenium oxide matrix. On the one hand, the polyacid, acting as a strong oxidant, stabilizes the high valence state of Ru, inhibiting excessive loss of lattice oxygen; on the other hand, the optimized electronic structure promotes the adsorption and activation of water molecules, effectively suppressing the lattice oxygen-mediated (LOM) mechanism that leads to lattice collapse, thereby fundamentally solving the problem of dissolution instability of ruthenium oxide in acidic environments.

[0020] 3. The RuO2@PW12 catalyst prepared in this invention exhibits excellent electrocatalytic performance in 0.5M H2SO4 solution, reaching 10 mA / cm². 2 The overpotential at current density is only 142 mV, and the Tafel slope is as low as 68.4 mV / dec, which is significantly better than commercial ruthenium dioxide catalysts (Aladdin, purity 99.9%, overpotential 307 mV, Tafel slope 243.4 mV / dec).

[0021] 4. The RuO2@PW12 catalyst of this invention exhibits excellent long-range stability under acidic conditions. In a 120-hour continuous electrolysis test, its voltage decay rate was extremely low, and it maintained a stable current density at a potential of 1.5V for more than 120 hours without significant activity decay, demonstrating superior durability compared to commercial ruthenium dioxide catalysts (Aladdin, 99.9% purity).

[0022] 5. The RuO2@PW12 catalyst of this invention exhibits extremely high precious metal utilization and economic efficiency. Its mass activity reaches 2.4 A / mg at a potential of 1.5V. Ru It is ruthenium oxide without polyacid modification (0.3A / mg). Ru It is 8 times that of ruthenium oxide, which is also a significant multiple of commercial ruthenium oxide. It effectively reduces the loading requirements of the precious metal iridium / ruthenium in the oxygen evolution reaction, and has significant economic benefits and prospects for industrial application. Attached Figure Description

[0023] Figure 1 Here is a scanning electron microscope (SEM) image of the catalyst in Example 1; Figure 2 The image shows a scanning electron microscope (SEM) image of the catalyst in Comparative Example 1. Figure 3 The image shows a scanning electron microscope (SEM) image of the catalyst in Comparative Example 2. Figure 4 This is a transmission electron microscope (TEM) image of the catalyst in Example 1; Figure 5 The graphs show the catalytic performance of the catalysts in Examples 1-3 and Comparative Examples 1-2 in a three-electrode system using linear voltammetry. In the graphs, a is a comparison of the hydrogen evolution reaction performance of the catalysts in different examples and the catalyst in Comparative Example 1, and b is a comparison of the electrocatalytic hydrogen evolution reaction performance of the catalyst in Example 1 and the commercial catalyst in Comparative Example 2. Figure 6 The images show the Tafel slope diagrams of the catalysts in Examples 1-3 and Comparative Examples 1-2, where a is a comparison diagram of the Tafel slopes of the catalysts in different examples and the catalyst in Comparative Example 1, and b is a comparison diagram of the Tafel slopes of the catalyst in Example 1 and the commercial catalyst in Comparative Example 2. Figure 7 The catalysts of Examples 1-3 and Comparative Example 1 at 10 mA / cm 2 Chronopotential curves at current density (i.e., stability test curves). Figure 8 The extended X-ray fine structure spectra of the catalysts in Example 1 and Comparative Example 1 are shown. Detailed Implementation

[0024] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0025] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0026] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0027] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0028] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0029] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0030] Example 1 Step 1: Preparation of precursor solution Weigh 0.75 g of ruthenium chloride hydrate (RuCl3·xH2O) into a beaker, add 70 mL of deionized water and 70 mL of anhydrous ethanol, and mix to form a water-ethanol mixed solvent system with a volume ratio of 1:1. While stirring continuously, slowly add 1 M potassium hydroxide (KOH) solution to adjust the pH of the system to approximately 7. Continue stirring for 1 hour until a precipitate forms.

[0031] Step 2: Washing and dispersing the precipitate The precipitate generated in step 1 was collected by centrifugation and washed five times with a mixture of water and ethanol (volume ratio 1:1) to remove impurity ions. Subsequently, the washed precipitate was redispersed in 140 mL of deionized water.

[0032] Step 3: Introduction of polyacids and hydrothermal reaction Add 50 mg of phosphotungstic acid (H3[PW]) to the dispersion in step 2. 12 O 40 [·nH2O, abbreviated as PW12]. Continue stirring at room temperature for 1 hour to ensure homogeneity. Then, transfer the mixture to a hydrothermal reactor and react at 190 °C for 24 hours.

[0033] Step 4: Post-processing After the hydrothermal reaction was completed, the product was cooled to room temperature, filtered, and washed with deionized water to collect the precipitated solid. The obtained solid was dried overnight in an oven at 80 °C to obtain the target product, RuO2@PW12 composite catalyst.

[0034] Experimental data and effects: The scanning electron microscope (SEM) image of the RuO2@PW12 catalyst prepared in this embodiment is as follows: Figure 1As shown, the acid-modified ruthenium oxide exhibits a loose and porous surface. Transmission electron microscopy (HAADF-STEM) images are shown below. Figure 4 As shown, a significant contrast difference was observed at the area marked by the red circle. Combined with EDS surface scanning, which showed that the distribution of W, P, Ru, and O elements was consistent, this confirmed the successful anchoring of the polyacid ligands on the ruthenium oxide surface.

[0035] The linear sweep voltammetry (LSV) curve of the RuO2@PW12 catalyst prepared in this embodiment in 0.5M H2SO4 electrolyte is shown below. Figure 5 As shown. At 10 mA / cm 2 At current density, its overpotential is only 142 mV, which is significantly lower than that of unmodified RuO2 (230 mV).

[0036] The Tafel slope of the RuO2@PW12 catalyst prepared in this embodiment is as follows: Figure 6 As shown, the value is 68.4 mV / dec, indicating that polyacid modification significantly improves the oxygen evolution reaction kinetics.

[0037] The stability test curve of the RuO2@PW12 catalyst prepared in this embodiment is as follows: Figure 7 As shown, it remained stable after 120 hours of continuous electrolysis, without significant attenuation, and its voltage attenuation rate was less than 15 μV / h.

[0038] Example 2 Add 50 mg of silicotungstic acid (H4[SiW)) to the dispersion in step 2. 12 O 40 [·nH2O, abbreviated as SiW12]. Stirring was continued at room temperature for 1 hour to ensure homogeneity. The mixture was then transferred to a hydrothermal reactor and reacted at 190 °C for 24 hours. All other steps were the same as in Example 1.

[0039] The linear sweep voltammetry (LSV) curve of the RuO2@SiW12 catalyst prepared in this embodiment in 0.5 M H2SO4 electrolyte is shown below. Figure 5 As shown. At 10 mA / cm 2 At current density, its overpotential is 205 mV, which is also lower than that of unmodified RuO2 (230 mV).

[0040] This implementation example The Tafel slope of the prepared RuO2@SiW12 catalyst is as follows: Figure 6 As shown, the value is 82.2 mV / dec, indicating that polyacid modification significantly improves the oxygen evolution reaction kinetics.

[0041] This implementation exampleThe stability test curves of the prepared RuO2@SiW12 catalyst are shown below. Figure 7 As shown, it remained stable after 120 hours of continuous electrolysis, without significant attenuation, and its voltage attenuation rate was less than 24 μV / h.

[0042] Example 3 Add 50 mg of phosphomolybdic acid (H3[PMo)) to the dispersion from step 2. 12 O 40 [·nH2O, abbreviated as PMo12]. Stirring was continued at room temperature for 1 hour to ensure homogeneity. The mixture was then transferred to a hydrothermal reactor and reacted at 190 °C for 24 hours. All other steps were the same as in Example 1.

[0043] The linear sweep voltammetry (LSV) curve of the RuO2@PMo12 catalyst prepared in this embodiment in 0.5 M H2SO4 electrolyte is shown below. Figure 5 As shown. At 10 mA / cm 2 At current density, its overpotential is 190 mV, which is also lower than that of unmodified RuO2 (230 mV).

[0044] The Tafel slope of the RuO2@PMo12 catalyst prepared in this embodiment is as follows: Figure 6 As shown, the value is 69.4 mV / dec, indicating that polyacid modification significantly improves the oxygen evolution reaction kinetics.

[0045] The stability test curve of the RuO2@PMo12 catalyst prepared in this embodiment is as follows: Figure 7 As shown, it remained stable after 120 hours of continuous electrolysis, without significant attenuation, and its voltage attenuation rate was less than 139 μV / h.

[0046] Comparative Example 1 (Unmodified RuO2) Step 1: Weigh 0.75 g of ruthenium chloride hydrate (RuCl3·xH2O) and dissolve it in 140 mL of a mixed solvent of water and ethanol (volume ratio 1:1).

[0047] Step 2: While stirring continuously, slowly add 1 M KOH solution to adjust the pH to approximately 7. After stirring for another hour, centrifuge to collect the precipitate and wash it five times with a water / ethanol mixture.

[0048] Step 3: Disperse the precipitate in 140 mL of deionized water, place it in a hydrothermal reactor, and hydrothermally heat it at 190 °C for 24 hours.

[0049] Step 4: Filter, wash, and dry at 80 °C overnight to obtain a pure phase RuO2 sample.

[0050] Test results for Comparative Example 1: The LSV curve of the RuO2 catalyst prepared in Comparative Example 1 is shown in Figure 1. Figure 5 As shown, at 10 mA / cm 2 The overpotential at the current density is 230 mV, and the Tafel slope is as follows: Figure 6 As shown, it is 136.4 mV / dec. Stability tests are as follows... Figure 7 As shown, its stability is significantly worse than that of Example 1.

[0051] A comparison of Example 1 and Comparative Example 1 shows that the present invention constructs a WO-Ru bonding interface by introducing phosphotungstic acid (PW12), which has redox activity, as a ligand to modify the surface of ruthenium oxide. Figure 8 As shown. This interface not only modulates the electronic structure of Ru (increasing the Ru valence state) and inhibits the loss of lattice oxygen (LOM mechanism) through the strong oxidizing properties of the polyacid; it also optimizes the interfacial hydrogen bond network by utilizing the hydrophilicity of the polyacid, which is beneficial for the exchange of water molecules (H2O) and protons (H+). + The mass transfer kinetics of RuO2@PW12 were investigated. Ultimately, the RuO2@PW12 catalyst achieved excellent acidic oxygen evolution stability (attenuation rate <15μV / h) while maintaining high activity (overpotential 142 mV), solving the technical problem of traditional RuO2 catalysts being unable to balance activity and stability.

[0052] A comparison of Example 2 and Comparative Example 1 shows that polyacids with slightly weaker acidic oxidizing properties have a slightly lower effect on activity enhancement, but can maintain good stability.

[0053] A comparison of Example 3 and Comparative Example 1 shows that polyacids with slightly stronger acidic oxidizing properties significantly improve activity but slightly reduce it, and also lead to a loss of stability.

[0054] Comparative Example 2 Comparative Example 2 is a commercial ruthenium dioxide catalyst (Aladdin, purity 99.9%, overpotential 307 mV, Tafel slope 243.4 mV / dec).

[0055] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0056] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A ruthenium oxide catalyst based on acidic oxidizing ligand modification, characterized in that, The ruthenium oxide catalyst comprises a ruthenium oxide matrix and an acidic oxidizing ligand modified on the surface of the ruthenium oxide matrix; The acidic oxidizing ligand is a polyoxometalate; The polyoxometalate is anchored to the ruthenium oxide matrix surface via heteroatom-oxygen-metal chemical bonds; The polyoxometalate is selected from one or more of Keggin-type polyoxometalates, Dawson-type polyoxometalates, Waugh-type polyoxometalates, and vacancy-type polyoxometalates.

2. The ruthenium oxide catalyst based on acidic oxidizing ligand modification according to claim 1, characterized in that, The polyoxometalates include one or more of silicotungstic acid, phosphotungstic acid, and phosphomolybdic acid.

3. The method for preparing the ruthenium oxide catalyst based on acidic oxidizing ligand modification according to any one of claims 1 to 2, characterized in that, Includes the following steps: A ruthenium metal salt precursor is dissolved in water, the pH is adjusted to 6-8, and a precipitate is formed to obtain a metal oxide precursor. The metal oxide precursor is dispersed in water, a polyoxometalate is added, and after mixing evenly, a hydrothermal reaction is carried out to obtain the ruthenium oxide catalyst based on acidic oxidizing ligand modification.

4. The preparation method according to claim 3, characterized in that, After adjusting the pH, continue the reaction for 0.5 to 2 hours.

5. The preparation method according to claim 3, characterized in that, The mass-to-volume ratio of the polyoxometalate and water in the hydrothermal reaction system is (3~8) mg: 14 mL.

6. The preparation method according to claim 4, characterized in that, The hydrothermal reaction is carried out at a temperature of 160~200℃ for a duration of 12~48h.

7. The application of the ruthenium oxide catalyst based on acidic oxidizing ligand modification as described in any one of claims 1 to 3 in the acidic oxygen evolution reaction.

8. An acidic oxygen evolution reaction electrode, characterized in that, The catalyst comprising the ruthenium oxide catalyst based on acidic oxidizing ligand modification as described in any one of claims 1 to 2.

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