A catalyst, a method for producing the same, and a method for producing 2,5-furandicarboxylic acid

Abstract

The application discloses a kind of catalyst and its preparation method and the preparation method of 2,5-furan dicarboxylic acid, belong to catalyst technical field.The catalyst is composed of nickel hydroxide carrier and ruthenium monatomic anchored in the crystal lattice of nickel hydroxide carrier;The nickel hydroxide carrier is layered nanosheet;The catalyst contains Ru-O coordination bond.The catalyst has excellent stability and higher catalytic activity and catalytic efficiency, and when it is applied to the electrocatalytic oxidation reaction of 5-hydroxymethylfurfural, higher 2,5-furan dicarboxylic acid selectivity can be obtained, and the catalyst of the reaction can be used repeatedly, and still has good stability after 20 continuous electrolytic cycles, significantly reduces the cost of efficient production of 2,5-furan dicarboxylic acid, is more conducive to environmental protection and atom utilization maximization, and has potential application value.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and more particularly to a catalyst and its preparation method and a method for preparing 2,5-furandicarboxylic acid. Background Technology

[0002] With the rapid depletion of fossil resources and the increasing severity of environmental problems, the development and utilization of new renewable resources has become an urgent need for social development. Biomass resources, as a sustainable renewable carbon source in nature, have advantages such as green production and environmental friendliness, and are considered a potential alternative to traditional fossil fuels. Compared with direct use as fuel, converting biomass into high-value-added products or intermediates for the synthesis of fine chemicals is an effective way to maximize the utilization of renewable energy.

[0003] 5-Hydroxymethylfurfural (HMF), as an important biomass-based platform derivative, can be converted into various high-value-added chemicals through different catalytic conversion pathways, and is widely used in fine chemicals, fuels, food additives, pharmaceuticals, and other fields. In particular, 2,5-furandicarboxylic acid (FDCA) prepared by the selective oxidation of 5-hydroxymethylfurfural (HMFOR) can be used to replace petroleum-derived terephthalic acid as a sustainable and biodegradable monomer feedstock for the production of bio-based polyesters, thereby promoting the establishment of a circular plastics economy. However, the thermocatalytic oxidation of 5-hydroxymethylfurfural typically requires high-temperature and high-pressure reaction conditions, thus making it impossible to efficiently prepare 2,5-furandicarboxylic acid under mild catalytic conditions.

[0004] The clean-energy-driven electrocatalytic oxidation of 5-hydroxymethylfurfural can be carried out at ambient temperature and pressure, achieving efficient biomass conversion under mild conditions. It represents a potential technology for the efficient preparation of 2,5-furandicarboxylic acid under mild conditions. This electrocatalytic oxidation of 5-hydroxymethylfurfural requires various catalysts. In recent years, nickel-based catalysts have been proven to be highly efficient catalysts for the electrooxidation of 5-hydroxymethylfurfural, attracting widespread attention from researchers. However, the stability of nickel-based catalysts has not been significantly improved; currently reported catalysts can only be recycled 5-10 times. This poor stability limits the widespread application of the electrocatalytic oxidation of 5-hydroxymethylfurfural for the efficient preparation of 2,5-furandicarboxylic acid.

[0005] Therefore, researching and developing a novel catalyst that combines high efficiency and good stability is of great significance for the electrocatalytic preparation of 2,5-furandicarboxylic acid from 5-hydroxymethylfurfural. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a catalyst and a method for preparing the same, as well as a method for preparing 2,5-furandicarboxylic acid. The catalyst exhibits excellent stability and high catalytic activity, and demonstrates high selectivity for 2,5-furandicarboxylic acid in the electrocatalytic oxidation of 5-hydroxymethylfurfural.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] This invention provides a catalyst composed of a nickel hydroxide support and ruthenium single atoms anchored within the lattice of the nickel hydroxide support;

[0009] The nickel hydroxide carrier is a layered nanosheet;

[0010] The catalyst contains Ru-O coordination bonds.

[0011] In the catalyst of this invention, ruthenium single atoms are monodispersed and anchored on a nickel hydroxide support. The ruthenium single atoms are bonded to the nickel hydroxide support through Ru-O coordination bonds, which gives the ruthenium single atoms excellent atomic utilization.

[0012] The present invention improves the electronic structure of nickel hydroxide support by introducing ruthenium single atoms, thereby giving the catalyst excellent stability and high catalytic activity and efficiency.

[0013] The strong interaction between ruthenium single atoms and nickel hydroxide support promotes the transfer of electrons from nickel to ruthenium single atoms, resulting in a higher valence state of Ni species in the catalyst of this invention.

[0014] Preferably, the catalyst of the present invention has an average size of 30-40 nm.

[0015] Preferably, the loading of ruthenium single atoms in the catalyst is 2wt%-4wt%.

[0016] The present invention also provides a method for preparing the above-mentioned catalyst, comprising the following steps:

[0017] The catalyst was obtained by slowly adding a nickel source, a ruthenium source, water, and an aqueous solution of sodium hydroxide to a mixed solution of sodium nitrate and formamide, controlling the pH to be 9-11, and then heating and co-precipitating.

[0018] The above preparation method uses a specific order of addition to better control the monodisperse state of the active component ruthenium atoms in the catalyst, and to make the overall nano-size of the catalyst smaller. By combining with the support nickel hydroxide through Ru-O coordination bonds, the catalyst has better stability and good catalytic activity and efficiency.

[0019] In the preparation method described in this invention, the content of ruthenium source should not be too high, as excessive content will affect the stability and catalytic activity of the catalyst.

[0020] Preferably, the molar ratio of nickel to ruthenium in the nickel source and ruthenium source is (30-50):1; more preferably (35-45):1; and even more preferably 39:1.

[0021] Preferably, the heating temperature is 78℃-82℃; more preferably, it is 80℃.

[0022] Preferably, the heating rate is 5-10°C / min; more preferably, it is 5-8°C / min.

[0023] The slow addition in the above preparation method can be achieved by adding dropwise or by other techniques well known to those skilled in the art.

[0024] Preferably, when the nickel source and ruthenium source are added to the mixed solution of sodium nitrate and formamide, the addition rate of the nickel source and ruthenium source is 2-8 mL / min; more preferably 4-6 mL / min; and even more preferably 5 mL / min.

[0025] Preferably, the nickel source of the present invention is selected from nickel nitrate hexahydrate or nickel chloride hexahydrate;

[0026] The ruthenium source is selected from ruthenium trichloride hydrate or potassium ruthenium chloride (III) pentahydrate.

[0027] In the above preparation method, formamide is used as an intercalation reagent, and sodium nitrate plays a role in neutralizing the charge during intercalation. The combination of the two makes the catalyst have thinner nanosheets. The thinner the catalyst nanosheets, the more catalytic sites are exposed, and the better the catalytic activity and catalytic efficiency.

[0028] Preferably, the volume fraction of formamide in the mixed solution of sodium nitrate and formamide is 20-25%; more preferably, it is 23%.

[0029] Preferably, the concentration of the sodium nitrate aqueous solution is 9-12 mmol / L; more preferably, it is 10 mmol / L.

[0030] Preferably, the concentration of the sodium hydroxide aqueous solution is 0.3-0.6 mol / L; more preferably, it is 0.5 mol / L.

[0031] The present invention also provides a method for preparing 2,5-furandicarboxylic acid, which is prepared by electrocatalytic oxidation of 5-hydroxymethylfurfural;

[0032] Preferably, the catalyst for the electrocatalytic oxidation reaction is the catalyst described above or the catalyst prepared by the method described above.

[0033] When the catalyst was used in the electrocatalytic oxidation of 5-hydroxymethylfurfural to prepare 2,5-furandicarboxylic acid, the reaction rate of the electrocatalytic oxidation reaction was higher, indicating that the catalyst of the present invention has higher catalytic activity.

[0034] The catalyst described in this invention exhibits superior stability. Cyclic testing showed that it maintained good stability even after 20 consecutive electrolysis cycles, with a conversion rate of 99.3% for the reactant 5-hydroxymethylfurfural, a selectivity of 98.2% for 2,5-furandicarboxylic acid, and a Faraday efficiency of 97.4%. Compared to existing technologies, the catalyst provided by this invention consists of a nickel hydroxide support and ruthenium single atoms anchored within the nickel hydroxide support lattice; the nickel hydroxide support is a layered nanosheet; and the catalyst contains Ru-O coordination bonds. This catalyst possesses excellent stability, high catalytic activity, and high catalytic efficiency. Its application in the electrocatalytic oxidation of 5-hydroxymethylfurfural yields high selectivity for 2,5-furandicarboxylic acid. Furthermore, the catalyst can be reused repeatedly, maintaining good stability even after 20 consecutive electrolysis cycles. This significantly reduces the cost of efficient 2,5-furandicarboxylic acid production, is more environmentally friendly, and maximizes atom utilization, demonstrating potential application value. Attached Figure Description

[0035] Figure 1 Transmission electron microscope image of the ruthenium single-atom / nickel hydroxide catalyst prepared in Example 1;

[0036] Figure 2 Aberration-corrected high-resolution transmission electron microscope image of the ruthenium single-atom / nickel hydroxide catalyst prepared in Example 1;

[0037] Figure 3 X-ray diffraction patterns of the ruthenium single-atom / nickel hydroxide catalyst prepared in Example 1 and the pure nickel hydroxide catalyst;

[0038] Figure 4 X-ray photoelectron spectra of the ruthenium single-atom / nickel hydroxide catalyst prepared in Example 1 and the pure nickel hydroxide catalyst;

[0039] Figure 5 The extended edges of the X-ray absorption fine structure spectra of the ruthenium single-atom / nickel hydroxide catalyst prepared in Example 1 and the reference sample ruthenium foil and ruthenium element in ruthenium dioxide (RuO2);

[0040] Figure 6 The current density curves at different potentials were tested when the ruthenium single-atom / nickel hydroxide catalyst prepared in Example 1 and pure nickel hydroxide were loaded on nickel foam, respectively.

[0041] Figure 7 The graph shows the concentration changes of reactants, products, and intermediates obtained under different transfer charge amounts for the ruthenium single-atom / nickel hydroxide catalyst prepared in Example 1.

[0042] Figure 8 The graph shows the changes in the conversion rate of 5-hydroxymethylfurfural, the selectivity of 2,5-furandicarboxylic acid, and the Faraday efficiency of the ruthenium single-atom / nickel hydroxide catalyst prepared in Example 1 over 20 consecutive electrolysis cycles. Detailed Implementation

[0043] To further illustrate the present invention, the following detailed description of the ruthenium single-atom / nickel hydroxide catalyst, its preparation method, and its application are provided in conjunction with embodiments.

[0044] I. Preparation of Ruthenium Single Atom / Nickel Hydroxide Catalysts

[0045] Example 1

[0046] This invention provides a ruthenium single-atom / nickel hydroxide catalyst with an average size of 30-40 nanometers, and its synthesis method is as follows:

[0047] 123.6 mL of a 10 mmol / L sodium nitrate aqueous solution and 36.8 mL of a formamide solution were mixed and heated in a water bath with magnetic stirring until the temperature reached 80 °C. The heating rate was 5 °C / min, and the magnetic stirring speed was 300 rpm / min. The volume fraction of the formamide solution in the mixed solution was 23%.

[0048] 1.83 mmol of nickel nitrate hexahydrate and 0.094 mmol of ruthenium trichloride hydrate were mixed and dissolved in 100 mL of deionized water to obtain a 100 mL mixed solution. 2 g of sodium hydroxide solid was dissolved in 100 mL of deionized water to obtain a 0.5 mol / L sodium hydroxide aqueous solution. 80 mL of the mixed solution of nickel nitrate hexahydrate and ruthenium trichloride hydrate was divided into two 40 mL portions and injected into the above mixed solution of sodium nitrate aqueous solution and formamide solution at an injection rate of 5 mL / min. During the injection, sodium hydroxide aqueous solution was added dropwise to adjust the pH to 9-11. After 8 min, the injection was stopped. Then, sodium hydroxide aqueous solution was added dropwise at a uniform rate for 2 min (the purpose of adding sodium hydroxide aqueous solution again is to make the co-precipitation reaction of sodium hydroxide with nickel ions and ruthenium ions more complete). The reaction was then stopped. Nitrogen gas was introduced into the resulting mixed solution and magnetically stirred for about 3 hours until the solution temperature reached room temperature.

[0049] The obtained sample was separated by filtration, washed three times with deionized water, and the final product was evenly dispersed with a small amount of deionized water and freeze-dried overnight at -45°C to obtain a ruthenium single atom / nickel hydroxide catalyst with a ruthenium single atom loading of 2.68 wt%.

[0050] Transmission electron microscope images of the ruthenium single-atom / nickel hydroxide catalyst prepared in this embodiment are shown below. Figure 1 As shown, the high-resolution transmission electron microscope image with spherical aberration correction is as follows: Figure 2 As shown, Figure 1 The ultrathin nanosheets are ruthenium single-atom / nickel hydroxide catalysts. Figure 2 The ruthenium single atoms are in a monodisperse state and are anchored on a nickel hydroxide substrate.

[0051] X-ray diffraction patterns of ruthenium single-atom / nickel hydroxide catalyst and pure nickel hydroxide catalyst are as follows: Figure 3 As shown, the X-ray diffraction patterns of the two catalysts are essentially identical, indicating that the introduction of ruthenium single atoms has no effect on the substrate. The X-ray photoelectron spectra are as follows: Figure 4 As shown, the Ni 2p peak indicates that the Ni species in the sample is indeed nickel hydroxide. Furthermore, compared to pure nickel hydroxide, the Ni 2p peak binding energy of the ruthenium single-atom / nickel hydroxide catalyst is higher, indicating a higher valence state of the Ni species in the ruthenium single-atom / nickel hydroxide catalyst. This is attributed to the strong interaction between the ruthenium single atom and the nickel hydroxide support, which promotes electron transfer from nickel to ruthenium. The extended edge of the X-ray absorption fine structure spectrum is shown below. Figure 5 As shown, both the ruthenium single-atom / nickel hydroxide catalyst and pure RuO2 are Ru-O coordinated, which is significantly different from the Ru-Ru coordination present in pure ruthenium foil.

[0052] II. Performance Testing Experiments of Ruthenium Single Atom / Nickel Hydroxide Catalysts

[0053] Performance Test Experiment 1

[0054] Ruthenium single-atom / nickel hydroxide catalyst as the effective component of electrocatalyst and test conditions for electrochemical oxidation of 5-hydroxymethylfurfural.

[0055] 2.5 mg of ruthenium single-atom / nickel hydroxide catalyst was dispersed in a mixed solution of 400 μL ethanol and 800 μL deionized water and sonicated until homogeneous. Then, 5 mg of carbon powder was added and sonicated for 1 hour to obtain a solution with very small carbon powder particle diameter. Immediately afterwards, 100 μL of 5% Nafion solution was added and sonicated for 1 hour to obtain a homogeneous mixed solution. 60 μL of the above solution was uniformly dropped onto a 0.5 × 0.5 cm² nickel foam as the working electrode, a silver / silver chloride electrode as the reference electrode, and a platinum wire electrode as the counter electrode. The electrochemical oxidation of 5-hydroxymethylfurfural to synthesize 2,5-furandicarboxylic acid was carried out in an H-type electrolytic cell, which was separated from the anode by a Nafion 115 proton exchange membrane. The anode chamber contained 30 mL of electrolyte with a concentration of 1 mol / L potassium hydroxide and 100 mmol / L 5-hydroxymethylfurfural, and the cathode chamber contained 30 mL of electrolyte with a concentration of 1 mol / L potassium hydroxide.

[0056] Performance Test Experiment 2

[0057] Current density and product selectivity test conditions of ruthenium single-atom / nickel hydroxide catalyst in the electrochemical oxidation of 5-hydroxymethylfurfural.

[0058] Under the reaction conditions of Performance Test Experiment 1, nickel foam was used as the working electrode, and the current density of the reaction was tested using linear sweep voltammetry. The potential of the relative reversible hydrogen electrode was set to 1.0-1.8V, and the scan rate was 5 mV / s. The hydrogen gas generated at the cathode during the reaction was discharged into the air. When the nickel foam electrode was used for testing, the effective current density generated by the electrocatalytic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid by the ruthenium single-atom / nickel hydroxide catalyst prepared in Example 1 of this invention and pure nickel hydroxide under the above relative reversible hydrogen electrode was as follows: Figure 6 As shown, to achieve a current density of 100 mA / cm², nickel hydroxide requires a potential of 1.54 V relative to the reversible hydrogen electrode, while the ruthenium single-atom / nickel hydroxide catalyst only requires a potential of 1.44 V relative to the reversible hydrogen electrode. The current density in the electrochemical reaction can be used to describe the electrochemical reaction rate at the electrode surface, thus demonstrating that the ruthenium single-atom / nickel hydroxide catalyst described in this invention has superior catalytic efficiency.

[0059] Under the reaction conditions of Performance Test Experiment 1, nickel foam was used as the working electrode, and constant potential testing was employed. An H-type electrolytic cell, with the anode and cathode separated by a Nafion 115 proton exchange membrane, was used for the reaction. The anode chamber contained 20 mL of electrolyte with a concentration of 1 mol / L potassium hydroxide and 10 mmol / L 5-hydroxymethylfurfural, while the cathode chamber contained 20 mL of 1 mol / L potassium hydroxide solution as the electrolyte. The relative reversible hydrogen electrode potential was set at 1.45 V, and constant potential electrolysis was performed for one cycle until the charge transfer reached 120 coulombs. During electrolysis, every 20 coulombs of charge transferred, 50 μL of solution was taken from the anode chamber and diluted to 2 mL with deionized water for subsequent product selectivity analysis.

[0060] Performance Test Experiment 3

[0061] The selectivity of the products from the electrochemical oxidation of 5-hydroxymethylfurfural using the ruthenium single-atom / nickel hydroxide catalyst prepared in Example 1 was analyzed by high-performance liquid chromatography (HPLC). The instrument used was an Agilent 5HC-C18 column equipped with a UV-Vis detector and a 4.6 mm × 250 mm wavelength. The UV detector wavelength was set to 265 nm. The mobile phase consisted of methanol and 5 mmol / L ammonium formate aqueous solution at a volume ratio of 3:7, and the flow rate was 0.6 mL / min. A 10 μL solution, diluted from the anode chamber, was injected into the chromatograph and separated for 10 minutes. The concentration changes of reactants, products, and intermediates within one electrolytic cycle (potential electrolysis until the charge transfer reached 120 coulombs) are shown below. Figure 7 As shown, within this cycle, the concentration of the reactant 5-hydroxymethylfurfural gradually decreases with increasing charge. At 100 coulombs, the concentration of the feedstock 5-hydroxymethylfurfural is approximately 1 mmol / L. When the charge transfer during constant-potential electrolysis reaches 120 coulombs, the reactant is almost completely converted into the product 2,5-furandicarboxylic acid. The concentration of the target product 2,5-furandicarboxylic acid gradually increases with increasing charge. At the end of electrolysis, the concentrations of the reactant 5-hydroxymethylfurfural and other intermediates are extremely low. Within one electrolysis cycle, the conversion rate of the reactant 5-hydroxymethylfurfural reaches 99.7%, the selectivity for 2,5-furandicarboxylic acid is 99.0%, and the Faraday efficiency of the reaction is 98.6%.

[0062] Performance Test Experiment 4

[0063] Stability testing of ruthenium single-atom / nickel hydroxide catalyst for the electrochemical oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid under a relatively reversible hydrogen electrode potential of 1.45 V.

[0064] Under the reaction conditions of Performance Test Experiment 1, constant potential testing was performed using carbon paper as the working electrode. An H-type electrolytic cell with the anode and cathode separated by a Nafion 115 proton exchange membrane was used. The anode chamber contained 20 mL of electrolyte with a concentration of 1 mol / L potassium hydroxide and 10 mmol / L 5-hydroxymethylfurfural, while the cathode chamber contained 20 mL of 1 mol / L potassium hydroxide solution as the electrolyte. The potential relative to the reversible hydrogen electrode was set to 1.45 V. Constant potential electrolysis was performed until the charge transfer reached 120 coulombs. Hydrogen gas generated at the cathode was released into the air. After each electrolysis cycle, 50 μL of the solution from the anode chamber was taken and diluted to 2 mL. The electrolyte in the anode chamber was quickly replaced, and the next electrolysis cycle was performed. The solutions taken from the anode chamber after multiple electrolysis cycles were then analyzed by liquid chromatography. Figure 8The graph shows the changes in the conversion rate of 5-hydroxymethylfurfural, the selectivity of 2,5-furandicarboxylic acid, and the Faradaic efficiency of the ruthenium single-atom / nickel hydroxide catalyst prepared in Example 1 over 20 electrolysis cycles. The results indicate that the catalyst described in this invention has excellent stability. After 5 electrolysis cycles, the conversion rate of 5-hydroxymethylfurfural was 99.2%, the selectivity of 2,5-furandicarboxylic acid was 99%, and the Faradaic efficiency of the reaction was 98.4%. The ruthenium single-atom / nickel hydroxide catalyst exhibits good stability.

[0065] After 20 electrolysis cycles, the conversion of 5-hydroxymethylfurfural was 99.3%, the selectivity for 2,5-furandicarboxylic acid was 98.2%, and the Faraday efficiency of the reaction was 97.4%. The ruthenium single-atom / nickel hydroxide catalyst exhibited good stability.

[0066] In summary, the ruthenium single-atom / nickel hydroxide catalyst described in this invention exhibits excellent stability, maintaining good stability and high catalytic activity and efficiency even after 20 electrolysis cycles. Furthermore, it demonstrates high selectivity and Faradaic efficiency for 2,5-furandicarboxylic acid in the electrocatalytic oxidation of 5-hydroxymethylfurfural. This provides a new approach for the low-cost, high-efficiency production of 2,5-furandicarboxylic acid and its widespread application. The above description of the embodiments is merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this invention.

Claims

1. A catalyst, characterized in that, It consists of a nickel hydroxide support and ruthenium single atoms anchored within the nickel hydroxide support lattice. The nickel hydroxide carrier is a layered nanosheet; The catalyst contains Ru-O coordination bonds; The catalyst has an average size of 30-40 nm; The catalyst is loaded with 2wt%-4wt% ruthenium single atoms.

2. A method for preparing a catalyst, characterized in that, Includes the following steps: 123.6 mL of 10 mmol / L sodium nitrate aqueous solution and 36.8 mL of formamide solution were mixed and heated in a water bath with magnetic stirring to 80 °C at a heating rate of 5 °C / min and a magnetic stirring speed of 300 rpm / min; the volume fraction of formamide solution in the mixed solution was 23%; 1.83 mmol of nickel nitrate hexahydrate and 0.094 mmol of ruthenium trichloride hydrate were mixed and dissolved in 100 mL of deionized water to obtain a 100 mL mixed solution. 2 g of sodium hydroxide solid was dissolved in 100 mL of deionized water to obtain a 0.5 mol / L sodium hydroxide aqueous solution. 80 mL of the mixed solution of nickel nitrate hexahydrate and ruthenium trichloride hydrate was divided into two 40 mL portions and injected into the above mixed solution of sodium nitrate aqueous solution and formamide solution at an injection rate of 5 mL / min. During the injection process, sodium hydroxide aqueous solution was added dropwise to adjust the pH to 9-11. After 8 min, the injection was completed. Then, sodium hydroxide aqueous solution was added dropwise at a uniform rate for 2 min, and the reaction was completed. The resulting mixed solution was purged with nitrogen gas and magnetically stirred for 3 hours until the solution temperature reached room temperature. The obtained sample was separated by filtration, washed three times with deionized water, and the final product was evenly dispersed with a small amount of deionized water and freeze-dried overnight at -45°C to obtain a ruthenium single-atom / nickel hydroxide catalyst. The ruthenium single-atom loading in the catalyst was 2.68 wt%, and the average size of the catalyst was 30-40 nanometers. The catalyst consisted of a nickel hydroxide support and ruthenium single atoms anchored in the lattice of the nickel hydroxide support. The nickel hydroxide support was a layered nanosheet, and the catalyst contained Ru-O coordination bonds.

3. A method for preparing 2,5-furandicarboxylic acid, characterized in that, 2,5-Furandicarboxylic acid was prepared by the electrocatalytic oxidation of 5-hydroxymethylfurfural. The catalyst for the electrocatalytic oxidation reaction is the catalyst described in claim 1 or the catalyst prepared by the preparation method described in claim 2.

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