Preparation and application of supported nanometer ruthenium dioxide catalyst

Abstract

This invention discloses a method for preparing supported RuO2 nanocatalysts and their applications. The method comprises: Step 1, adding an aqueous solution containing sulfite ions to an aqueous solution of Ru precursor to carry out a complexation reaction, thereby obtaining [Ru(SO3)3]. 3‑ Step 1: Add an alkaline aqueous solution to the reaction system from Step 1 to adjust the pH value, causing the complex to precipitate. Step 2: Wash the precipitate and react it with H2O2 to obtain a ruthenium oxide colloidal dispersion. Step 4: Add a support to the colloidal dispersion for impregnation, then centrifuge, wash, and dry to obtain the supported ruthenium dioxide nanocatalyst. The preparation method provided by this invention avoids the adsorption and poisoning of chloride ions on the catalyst surface. Furthermore, the use of H2O2 as an oxidant instead of air for heating and oxidation results in a lower reaction temperature, which prevents RuO2 agglomeration and growth, thus contributing to improved catalyst activity.

Description

Technical Field

[0001] This invention belongs to the field of catalysis technology, specifically relating to a method for preparing ruthenium dioxide nanocatalysts and their applications. Background Technology

[0002] Compared with other oxides, ruthenium dioxide (RuO2) exhibits good electrical conductivity and possesses a wide range of chemical valence states. During the transition between different valence states, ruthenium dioxide materials exhibit low internal stress and structural stability, making them promising for applications in chlor-alkali and chlorate production, electrocatalysis, and supercapacitors. Extensive research indicates that the catalytic performance of RuO2 is related to the unsaturated Ru atoms coordinated on the RuO2(110) surface. Nanoscale RuO2 exhibits better reactivity and higher utilization efficiency; therefore, the research and development of supported RuO2 nanocatalysts is of great significance.

[0003] The preparation of supported ruthenium dioxide nanocatalysts often employs a method of sodium hydroxide precipitation followed by oxidation. For example, Chinese patent CN1522176A discloses a method for preparing alumina-supported ruthenium and a method for oxidizing alcohols. The applicant reacts sodium hydroxide with RuCl3 to obtain a Ru(OH)3 / alumina intermediate, and then oxidizes it in air to obtain RuO2 / alumina. Other researchers have first precipitated RuCl3 with alkaline substances such as NaOH or NaHCO3, then gelled it, and then oxidized it in solution using hydrogen peroxide or chlorine, or by thermal oxidation, to prepare nano-RuO2. Some researchers have also used organorubber as a precursor to prepare nano-sized RuO2 using chemical vapor deposition, and applied it to high-performance supercapacitor materials and gas sensors (J Electrochem Soc, 2005). Liu et al. proposed preparing RuO2 using magnetron sputtering technology (Small, 2005). US20130059078A1 discloses a method for preparing RuO2, which involves obtaining a seed layer through organometallic atomic deposition, and then using RuO4 vapor as a precursor to form a RuO2 nanofilm through the reaction between RuO4 and the seed layer. Industrially, RuO2 is often prepared by directly oxidizing ruthenium to decompose and vaporize it and react it with oxygen. However, this method has low preparation efficiency, is difficult to separate, and cannot control particle size. Moreover, the entire process requires sophisticated equipment. Calcination methods, such as directly calcining ruthenium powder, ruthenium sulfide, or ruthenium sulfate, result in ruthenium dioxide powder with large differences in particle size and grain shape and poor uniformity, making it only suitable for manufacturing high-resistivity materials and limiting its application range.

[0004] In summary, supported nano-RuO2 catalysts still face challenges such as complex preparation processes, large RuO2 nanoparticle size, severe particle agglomeration, difficulty in uniform dispersion on the support, and weak interaction with the support. With the development and utilization of ruthenium resources, and the increasing attention RuO2 is receiving in the new energy field due to its excellent electrochemical and catalytic performance, how to prepare high-performance supported nano-RuO2 catalysts that achieve highly uniform dispersion of RuO2 on the support surface with small particle size, low impurity content on the catalyst surface, and high reactivity is an important research topic for Ru utilization both domestically and internationally, and also one of the key technologies for Ru resource development and utilization. Summary of the Invention

[0005] To address the problems in existing technologies, this invention provides a method for preparing supported RuO2 nanocatalysts. Unlike the traditional method of directly precipitating RuCl3 with an alkaline solution and then oxidizing it to prepare RuO2, this invention uses a ligand substitution method to replace chloride ions in RuCl3, avoiding the adsorption and poisoning of chloride ions on the catalyst surface, resulting in high catalyst activity. Secondly, this invention uses liquid H2O2 as the oxidant instead of air for heating oxidation, resulting in a lower reaction temperature and preventing RuO2 agglomeration and growth. Thirdly, this invention uses an aqueous synthesis system, which is simple and solves the problems of complex processes, harsh conditions, and difficulty in mass production of existing supported RuO2 nanocatalysts.

[0006] To achieve the above technical objectives, the technical solution of the present invention is as follows:

[0007] A method for preparing a supported RuO2 nanocatalyst includes the following steps:

[0008] Step 1: Add the aqueous solution containing sulfite ions to the aqueous solution of the Ru precursor to carry out a complexation reaction, thereby obtaining [Ru(SO3)3]. 3- Complexes;

[0009] Step 2: Add an alkaline aqueous solution to the reaction system from Step 1 to adjust the pH value, so that the complex precipitates out in the form of a precipitate;

[0010] Step 3: After washing the precipitate, react it with H2O2 to obtain a ruthenium oxide colloidal dispersion;

[0011] Step 4: Add the carrier to the colloidal dispersion for impregnation. After impregnation, centrifuge, wash, and dry to obtain the supported RuO2 nanocatalyst.

[0012] Preferably, the above preparation method specifically includes the following steps:

[0013] Step 1: Add the water-soluble Ru precursor to deionized water and sonicate until completely dissolved to prepare an aqueous solution of the Ru precursor;

[0014] Step 2: Slowly add the aqueous solution containing sulfite ions dropwise to the precursor aqueous solution of Ru at room temperature while stirring. Stop adding the solution when the color changes from red to light green. At this point, the ligand of Ru is converted from chloride ions to sulfite ions.

[0015] Step 3: Slowly add the alkaline aqueous solution to the reaction system in Step 2 while stirring, and adjust the pH of the reaction system to 8-11. The reaction system gradually changes from light green to dark green solution.

[0016] Step 4: Keep the pH of the reaction system constant and continue to add an aqueous solution containing sulfite ions dropwise to the dark green solution from Step 3 under stirring. A blue-green precipitate will form in the reaction system. Stop adding the solution when the blue-green precipitate stops precipitating. Continue the reaction for 1-2 hours after the addition is complete to ensure complete precipitation.

[0017] Step 5: Wash and filter the blue-green precipitate generated in step 4 with a large amount of deionized water and dry it to obtain blue-green ruthenium sulfite powder.

[0018] Step 6: Under stirring conditions, dissolve the blue-green ruthenium sulfite powder in a dilute acid aqueous solution, add the carrier material, disperse it ultrasonically, add H2O2 aqueous solution dropwise to the reaction system, heat the reaction for 2-3 hours, cool down, and continue to add acidic aqueous solution to promote the precipitation of RuO2 on the carrier surface.

[0019] Step 7: Centrifuge the reaction solution from Step 6 and wash it with a large amount of deionized water. After solid-liquid separation, dry the solution to obtain the supported RuO2 nanocatalyst.

[0020] Preferably, the Ru precursor in step 1 is one or more of ruthenic acid, ruthenic trichloride, potassium ruthenate, sodium ruthenate, and ammonium ruthenate, and the Ru concentration in the aqueous solution of the Ru precursor is 5-50 g / [.

[0021] Preferably, in step 2, the slow dripping rate is 1-3 mL / min, the stirring speed is 200-1000 r / min, the sulfite aqueous solution is one or more of sulfurous acid, sodium sulfite, sodium bisulfite, potassium sulfite, and potassium bisulfite aqueous solution, the concentration of sulfite ions in the aqueous solution is 50-100 g / L; when the solution turns light green, the pH of the reaction system is 4-5, and the molar ratio of sulfite ions to Ru ions in the reaction system is 5:1 to 20:1.

[0022] Preferably, the alkaline aqueous solution in step 3 is added at a rate of 5-10 mL / min and stirred at a speed of 200-1000 r / min. The alkaline aqueous solution is one or more of the following: sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, or ammonia.

[0023] Preferably, in step 4, the pH of the reaction system is 7.5-10, the stirring speed is 200-1000 rpm, and the reaction temperature is 0-60℃.

[0024] Preferably, in step 6, the dilute acid solution is one or more of dilute sulfuric acid, dilute hydrochloric acid, and acetic acid aqueous solution, with a concentration of 0.05-0.2 mol / L; the pH of the reaction system is 2-5; the molar ratio of H2O2 added to ruthenium sulfite salt in step 6 is 1:1-5:1; the reaction temperature is 60-90℃; and the carrier includes one or more of activated carbon, conductive carbon, mesoporous carbon, carbon aerosol, aluminum oxide, silicon dioxide, zirconium dioxide, and cerium dioxide.

[0025] Preferably, the solid-liquid separation method in step 7 is centrifugation or filtration; the drying temperature is 30-60℃.

[0026] The RuO2 nanoparticles in the catalyst prepared by the above method of the present invention have a particle size of 1-5 nanometers.

[0027] The supported RuO2 nanocatalyst prepared by the above method of the present invention can be used in the oxygen evolution reaction of water electrolysis.

[0028] The reason for using a water-soluble Ru precursor in step 1 is that water-soluble Ru precursors are easy to prepare and relatively inexpensive, and aqueous synthesis helps with subsequent large-scale production, has less environmental pollution, and lower preparation costs.

[0029] Step 2 involves slowly adding the sulfite precursor solution to the Ru precursor aqueous solution, utilizing the strong coordination of the sulfite ion to complex with Ru, thus obtaining [Ru(SO3)3]. 3- The complex can displace chloride ions, and the adsorption of chloride ions on the catalyst surface is the main reason for the low performance of RuO2 nanocatalysts. Therefore, [SO3] is used. 2- After the ligand replaces the chloride ion, SO3 2- It is an inorganic compound stabilizer that protects subsequently formed ruthenium oxide nanoparticles, preventing agglomeration, and SO3 2- It can be removed automatically during the subsequent oxidation and drying process and will not be strongly adsorbed on the catalyst surface.

[0030] The purpose of slowly adding sulfite in step 2 is to control the amount of sulfite added. Because sulfite has a reducing property, adding it too quickly can easily cause the Ru precursor to be reduced directly, preventing the formation of [Ru(SO3)3]. 3- Complexes;

[0031] The alkaline aqueous solution is slowly added in step 3 to adjust the pH of the reaction system to be weakly alkaline, because [Ru(SO3)3]3- The complex exists in ionic form in both strong acid and strong alkaline solutions, and only precipitates out as a green precipitate when the pH is weakly alkaline.

[0032] The addition of sulfite solution in step 4 is to ensure complete precipitation, guaranteeing that 100% of the Ru species in the solution precipitates out of the solution and is completely converted into ruthenium sulfite.

[0033] The use of a large amount of deionized water in step 5 is to ensure the effective removal of impurity ions;

[0034] H2O2 is used as the oxidant in step 6 because the product of the reaction is water, which will not pollute the reaction system. Moreover, liquid H2O2 replaces air for heating and oxidation, resulting in a lower reaction temperature, which can prevent RuO2 from agglomerating and growing. The addition of dilute acid aqueous solution after the reaction is to destroy the colloidal stability of RuO2. Subsequent solid-liquid separation is used to obtain supported RuO2 nanocatalyst.

[0035] The drying temperature in step 7 is maintained at 30-60℃ to avoid the aggregation of RuO2 nanoparticles caused by high-temperature drying.

[0036] As can be seen from the above description, the present invention has the following advantages:

[0037] 1. Unlike the traditional method of directly precipitating RuCl3 with an alkaline solution and then oxidizing it to prepare RuO2, this invention replaces the chloride ions in RuCl3 with a ligand substitution method, which avoids the adsorption and poisoning of chloride ions on the catalyst surface and results in high catalyst activity;

[0038] 2. This invention uses liquid H2O2 as an oxidant instead of air for heating oxidation, resulting in a lower reaction temperature and preventing RuO2 from agglomerating and growing.

[0039] 3. This invention can prepare small-sized and well-dispersed RuO2 nanocatalysts in aqueous solution without the addition of a protective agent. It is simple to operate, has mild reaction conditions, is environmentally friendly, has low production costs, and is easy to scale up. Attached Figure Description

[0040] Figure 1 This is a TEM image of the RuO2 / C catalyst prepared in Comparative Example 1 of this invention.

[0041] Figure 2 This is the XRD pattern of the RuO2 / C catalyst prepared in Comparative Example 1 of this invention.

[0042] Figure 3 This is a TEM image of the RuO2 / C catalyst prepared in Example 1 of this invention.

[0043] Figure 4 This is the XRD pattern of the RuO2 / C catalyst prepared in Example 1 of this invention. Detailed Implementation

[0044] The present invention will be specifically described below with reference to examples. Unless otherwise specified, the raw materials used in the following embodiments and comparative examples are all commercially available conventional raw materials.

[0045] Comparative Example 1

[0046] Preparation of RuO2 / C nanocatalysts supported on activated carbon

[0047] At room temperature, 1 g RuCl3 and 1.5 g XC-72R carbon black were ultrasonically dispersed and dissolved in 10 mL of deionized water. A 50 g / L sodium hydroxide aqueous solution was added dropwise at a rate of 2 mL / min. The addition was stopped when the pH of the reaction system rose to 13. After the reaction was allowed to stand for five days, Ru(OH)3 / XC-72R precipitate was formed at the bottom of the container. After centrifugation and drying, Ru(OH)3 / XC-72R solid powder was obtained. After heat treatment at 300 degrees Celsius in air for 1 hour, RuO2 / XC-72R catalyst was obtained. XRD and TEM characterization revealed that the ruthenium oxide particles in the prepared catalyst were large and severely agglomerated. Furthermore, some ruthenium oxide decomposed into reduced metallic Ru during heat treatment in air.

[0048] The electrochemical activity of the obtained catalyst was evaluated using a rotating disk electrode. The specific steps were as follows: Approximately 5 mg of the prepared RuO2 / C catalyst was accurately weighed and mixed with 20 μL of Nafion (5 wt%) solution and 5 mL of ethanol. The mixture was ultrasonically sonicated to obtain a uniformly dispersed catalyst slurry. Then, 10 μL of the catalyst slurry was transferred and coated onto a GC rotating disk electrode with an area of ​​0.19625 cm². After drying, the working electrode was obtained. The activity of the catalyst for the oxygen evolution reaction in water electrolysis was evaluated in a 0.1 M sulfuric acid aqueous solution under nitrogen atmosphere. Specifically, at room temperature, the scan rate was 10 mV / s from 0 V to 1.2 V, and the data was recorded at 10 mA / cm². 2 The overpotential corresponding to the electrolysis current for the oxygen evolution reaction (OER) is determined by the electrolysis current. A lower overpotential indicates higher OER reactivity of RuO2 / C. The RuO2 / XC-72R obtained in Comparative Example 1 exhibits an OER at 10 mA / cm². 2 The corresponding oxygen evolution reaction overpotential is 400mV.

[0049] Example 1

[0050] Step 1: Under room temperature conditions, ultrasonically disperse and dissolve 1 gram of RuCl3 in 75 mL of deionized water to prepare a RuCl3 aqueous solution with a concentration of 5 g Ru / L (calculated as Ru).

[0051] Step 2: Add a 50 g / L sodium bisulfite aqueous solution dropwise to the RuCl3 aqueous solution at a rate of 2 mL / min. Stop adding the solution when the reaction system changes from reddish-brown to light green. At this point, the pH of the solution is approximately 4-5.

[0052] Step 3: Adjust the pH of the reaction system with sodium carbonate aqueous solution until it reaches 12, then stop adding the solution. The reaction system will gradually change from light green to dark green.

[0053] Step 4: Using sodium carbonate aqueous solution to maintain the pH value of the reaction system, continue to add sulfite aqueous solution dropwise to the dark green solution in step 3 under stirring. A blue-green precipitate will be formed in the reaction system. Continue to stir the reaction at room temperature for 1 hour to ensure complete precipitation.

[0054] Step 5: Use a centrifuge to separate the white precipitate from the supernatant, and wash the blue-green precipitate with a large amount of deionized water until there are no chloride ions in the precipitate.

[0055] Step 6: Dissolve the washed blue-green precipitate in 0.2 mol / L dilute sulfuric acid solution to obtain a light blue transparent liquid. Then add 1.48 g of Xc-72R carbon black, and after ultrasonic dispersion, add excess H2O2 aqueous solution (30 wt% H2O2 aqueous solution, where the molar ratio of H2O2 to Ru is 2:1). Control the reaction temperature of the reaction system at 80 degrees Celsius. During the heating process and reaction, a condenser should be installed to prevent excessive evaporation of water and ensure that the concentration of reactants in the reaction system remains constant. After reacting for 3 hours, after cooling, add 20 mL of 0.5 mol / L sulfuric acid solution to the reaction system and let it stand for 1 hour.

[0056] Step 7: Centrifuge the reaction solution from Step 6 and wash it with a large amount of deionized water. Place the solid obtained after centrifugation in a vacuum oven and dry it at 40 degrees Celsius for 4 hours to obtain ruthenium oxide nanocatalyst.

[0057] Figure 2 The XRD pattern of the prepared RuO2 / XC-72R nanocatalyst is shown. The broadening of the corresponding XRD diffraction peaks indicates that the prepared RuO2 / XC-72R nanocatalyst particles are small. The average grain size of the ruthenium oxide particles is about 1.0 nm, which can be calculated using the Scherrer equation.

[0058] The catalytic activity of the RuO2 / XC-72R catalyst prepared in Example 1 was tested using the same apparatus and activity evaluation method as in Comparative Example 1. The results showed that, under the same test conditions, the RuO2 / XC-72R catalyst prepared in Example 1 exhibited a catalytic activity of 10 mA / cm². 2The oxygen evolution reaction overpotential at the current density was 250 mV, which was 150 mV lower than that of the catalyst prepared in the comparative example, indicating high oxygen evolution reaction activity.

[0059] Example 2

[0060] The specific experimental steps in this embodiment are similar to those in Example 1, except that the carbon support used is KB-300J conductive carbon black, and the amount of Ru precursor used is 50g. Ru The solution is potassium ruthenium chloride (KLCI) at a concentration of 50 g / L. The sulfite precursor solution is a 50 g / L potassium sulfite aqueous solution. The sulfite is added to the Ru precursor at a rate of 5 ml / min. When the solution changes from reddish-brown to light green, the molar ratio of sulfite solution to Ru precursor in the reaction system is 10:1, and the pH is approximately 4. The stirring speed is maintained at 1000 rpm. The pH of the reaction system is adjusted to 10 using sodium hydroxide aqueous solution, and the addition is stopped. At this point, the solution color turns dark green, and a small amount of blue-green precipitate forms. The potassium sulfite aqueous solution is continued to be added to the reaction system until the precipitation stops. Subsequent steps are the same as in Example 1. In this example, the RuO2 / KB-300J catalyst has a loading of 30 wt%, with a RuO2 to KB-300J mass ratio of 3:7.

[0061] The obtained RuO2 / KB-300J catalyst was evaluated for its oxygen evolution reaction activity using a rotating disk electrode, following the same procedures as in Example 1. The results showed that the oxygen evolution reaction activity was 10 mA / cm². 2 At the oxygen evolution current density, the oxygen evolution reaction overpotential of RuO2 / KB-300J prepared in Example 2 was 243mV, which was 157mV lower than that of RuO2 / XC-72R prepared in the comparative example.

[0062] Example 3

[0063] The specific experimental steps in this embodiment are similar to those in Example 1, except that carbon nanotubes are used as the carbon support, and the amount of Ru precursor used is 40g. Ru The solution contains ruthenium acetate at a concentration of 80 g / L, and the sulfite precursor solution is an 80 g / L potassium sulfite aqueous solution. The sulfite is added to the Ru precursor at a rate of 4 ml / min. When the solution changes from reddish-brown to light green, the molar ratio of sulfite solution to Ru precursor in the reaction system is 20:1, and the pH is approximately 5. The stirring speed is maintained at 800 rpm. The pH of the reaction system is adjusted to 10.5 using sodium hydroxide aqueous solution, and the addition is stopped. At this point, the solution color turns dark green, and a small amount of blue-green precipitate forms. Potassium sulfite aqueous solution is continued to be added to the reaction system until the precipitation stops. Subsequent steps are the same as in Example 1. In this example, the RuO2 / carbon nanotube catalyst has a loading of 40 wt%, where the mass ratio of RuO2 to KB-300J is 4:6.

[0064] The obtained RuO2 / carbon nanotube catalyst was evaluated for its oxygen evolution reaction activity using a rotating disk electrode, following the same procedures as in Example 1. The results showed that 10 mA / cm²... 2 At the oxygen evolution current density, the oxygen evolution reaction overpotential of RuO2 / KB-300J prepared in Example 3 was 213mV, which was 187mV lower than that of RuO2 / XC-72R prepared in the comparative example.

[0065] It is understood that the above detailed description of the present invention is for illustrative purposes only and is not intended to limit the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effects; as long as the usage requirements are met, they are all within the protection scope of the present invention.

Claims

1. A method for preparing a supported RuO2 nanocatalyst, characterized in that, The method includes the following steps: Step 1: Dissolve the water-soluble Ru precursor in deionized water to prepare an aqueous solution of the Ru precursor; Step 2: Add the aqueous solution containing sulfite ions dropwise to the Ru precursor aqueous solution at room temperature while stirring. Stop adding the solution when the color changes from red to light green. The Ru ligand is converted from chloride ions to sulfite ions. Step 3: Add the alkaline aqueous solution dropwise to the reaction system in Step 2 while stirring, and adjust the pH of the reaction system to 8-11. The reaction system will gradually change from a light green solution to a dark green solution. Step 4: Keep the pH of the reaction system constant and continue to add an aqueous solution containing sulfite ions dropwise to the dark green solution from Step 3 under stirring. A blue-green precipitate will form in the reaction system. Stop adding the solution after the blue-green precipitate stops precipitating. Then continue the reaction for 1-2 hours to ensure complete precipitation. Step 5: Wash the blue-green precipitate generated in Step 4 with deionized water, filter and dry it to obtain blue-green ruthenium sulfite. Step 6: Under stirring conditions, dissolve the blue-green sulfite powder in an acidic aqueous solution, add the carrier, disperse it by ultrasonication, add H2O2 aqueous solution dropwise to the reaction system, heat the reaction for 2-3 hours, cool down, and continue to add acidic aqueous solution to promote the precipitation of RuO2 on the surface of the carrier. Step 7: Centrifuge the reaction solution from Step 6 and wash it with deionized water. After solid-liquid separation, dry it to obtain the supported RuO2 nanocatalyst. In step 4, the pH of the reaction system is 7.5-10, the stirring speed is 200-1000 rpm, and the reaction temperature is 0-60°C. o C; The particle size of the supported RuO2 nanoparticles is 1-5 nanometers; The carrier includes one or more of the following: activated carbon, conductive carbon, mesoporous carbon, carbon aerosol, aluminum oxide, silicon dioxide, zirconium dioxide, and cerium dioxide.

2. The preparation method according to claim 1, characterized in that, In step 1, the Ru precursor is one or more of ruthenic acid, ruthenic trichloride, potassium ruthenate, sodium ruthenate, and ammonium ruthenate, and the Ru concentration in the aqueous solution of the Ru precursor is 5-50 g / L.

3. The preparation method according to claim 1, characterized in that, In step 2, the dropping rate is 1-3 mL / min, the stirring speed is 200-1000 r / min, the sulfite aqueous solution is one or more of sulfurous acid, sodium sulfite, sodium bisulfite, potassium sulfite, and potassium bisulfite aqueous solution, the concentration of sulfite ions in the aqueous solution is 50-100 g / L; when the solution turns light green, the pH of the reaction system is 4-5, and the molar ratio of sulfite ions to Ru ions in the reaction system is 5:1 to 20:

1.

4. The preparation method according to claim 1, characterized in that, In step 3, the alkaline aqueous solution is added at a rate of 5-10 mL / min and stirred at a rate of 200-1000 r / min. The alkaline aqueous solution is one or more of the following: sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, or ammonia.

5. The preparation method according to claim 1, characterized in that, In step 6, the acidic aqueous solution is one or more of dilute sulfuric acid, dilute hydrochloric acid, and acetic acid aqueous solution, with a concentration of 0.05-0.2 mol / L. The pH of the reaction system for the heating reaction is maintained at 2-5, and the molar ratio of H2O2 added to sulfite is 1:1-5:

1. The reaction temperature is 60-90°C. o C; In step 7, the solid-liquid separation method is centrifugation or filtration; the drying temperature is 30-60°C. o C.

6. The application of a supported RuO2 nanocatalyst prepared by any one of the preparation methods in claims 1-5 in the oxygen evolution reaction of water electrolysis.

Images