A ruthenium cobalt oxide self-supporting electrode, a preparation method and application thereof
By growing cobalt-doped ruthenium dioxide nanoparticles in situ on a titanium mesh, a self-supporting electrode was prepared, which solved the problem of easy oxidation of ruthenium-based catalysts at high potentials and realized efficient high-current-density water electrolysis for hydrogen production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- QINGDAO UNIV OF SCI & TECH
- Filing Date
- 2025-02-27
- Publication Date
- 2026-05-19
AI Technical Summary
Existing acidic water electrolysis catalysts for hydrogen production are prone to oxidation and dissolution at high potentials, leading to a decline in catalytic performance and making it difficult to meet the industrial demands for high current densities.
Cobalt-doped ruthenium dioxide nanoparticles were grown in situ on a titanium mesh using a hydrothermal method to form a self-supporting electrode. Cobalt doping was used to improve the electronic stability of ruthenium, thus preparing a high-performance electrocatalyst.
The catalyst's activity and stability are improved, enabling it to exhibit good performance at high current densities. The process is simple and controllable, making it suitable for water electrolysis devices.
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Figure CN119980295B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electrocatalyst technology, specifically to a ruthenium cobalt oxide self-supporting electrode, its preparation method, and its application. Background Technology
[0002] With the environmental problems caused by the large-scale use of fossil fuels, the development of clean and renewable energy sources has become urgent. Water electrolysis for hydrogen production, as a green, pollution-free, and sustainable method, is considered an ideal approach. Compared to traditional alkaline water electrolysis, acidic water electrolysis offers advantages such as high gas purity, high operating current density, and low energy consumption, making it a highly efficient hydrogen production technology. Acidic electrocatalysts are typically noble metal-based. Ruthenium-based catalysts, due to their high catalytic activity, lower cost than iridium, and greater reserves, have been considered as candidate materials to replace iridium-based catalysts. However, at high potentials, ruthenium-based materials are easily oxidized and dissolved, affecting their performance. In recent years, numerous water electrolysis catalysts have been researched and developed; however, most catalysts have low current densities, failing to meet the requirements of industrial water electrolysis for hydrogen production. Therefore, the preparation of low-cost, high-performance electrocatalysts capable of achieving high current density catalysis is of great significance for promoting the practical application of water electrolysis for hydrogen production. Summary of the Invention
[0003] In view of the above situation and to overcome the defects of the prior art, the present invention provides a ruthenium cobalt oxide self-supporting electrode, its preparation method and application, so as to solve the problems involved in the background art.
[0004] To achieve the above objectives, the present invention provides the following technical solution: a ruthenium cobalt oxide self-supporting electrode, which uses a titanium mesh as a substrate, and grows ruthenium dioxide nanoparticles in situ on the titanium mesh using a hydrothermal method with a hydrochloric acid aqueous solution of ruthenium chloride and cobalt chloride. Cobalt atoms are incorporated into the ruthenium dioxide lattice to form a cobalt-doped ruthenium dioxide self-supporting electrode, which is used as an electrocatalyst for oxygen evolution reaction and hydrogen evolution reaction.
[0005] Method for fabricating ruthenium cobalt oxide self-supporting electrodes
[0006] 1) Place the cut titanium meshes into the cleaning solution one by one and clean them ultrasonically; immerse the ultrasonically cleaned titanium meshes in hydrochloric acid solution for etching; then rinse them with the cleaning solution and dry them.
[0007] 2) Add ruthenium chloride and cobalt chloride to the hydrochloric acid solution and stir thoroughly at room temperature to dissolve;
[0008] 3) Take a piece of titanium mesh treated in 1), immerse it in the solution in 2), and then transfer it together to a reaction vessel lined with polytetrafluoroethylene for reaction. After cooling to room temperature, remove the titanium mesh, rinse it, and dry it to obtain a ruthenium cobalt oxide self-supporting electrode.
[0009] Furthermore,
[0010] The titanium mesh in step 1) is sequentially cleaned with acetone, ethanol and deionized water, and then rinsed with ethanol and deionized water after etching.
[0011] Furthermore, in step 1), the process involves ultrasonication for 10 minutes, etching at 90°C for 15 minutes, drying at 60°C for 6 hours, and using a hydrochloric acid solution with a mass fraction of 18%.
[0012] Furthermore, in step 2), the hydrochloric acid solution has a mass fraction of 0.5%, the molar ratio of ruthenium chloride to cobalt chloride is 1:1.74, the concentration of ruthenium chloride is 38.6 mM, and the concentration of cobalt chloride is 67.2 mM.
[0013] Furthermore, in step 3), the reaction conditions are 200°C for 20 hours, followed by alternating rinsing with deionized water and ethanol, and drying at 60°C for 6 hours.
[0014] An application of a ruthenium cobalt oxide self-supporting electrode for oxygen evolution reaction, hydrogen evolution reaction, and total water hydrolysis.
[0015] Furthermore,
[0016] 1) Using a cobalt ruthenium oxide self-supporting electrode as the working electrode, its oxygen evolution and hydrogen evolution performance were tested in a three-electrode system;
[0017] 2) Assemble a complete water splitting device using cobalt ruthenium oxide self-supporting electrodes.
[0018] Furthermore, in the three-electrode system described in 1), the working electrode is a cobalt-ruthenium oxide self-supporting electrode, and the size of each electrode is 1*1cm. The reference electrode and the counter electrode are a reversible hydrogen electrode and a platinum sheet electrode, respectively. The electrolyte used in the test is a 0.5MH2SO4 solution.
[0019] Furthermore, the water-splitting device described in 2) is a dual-electrode electrocatalytic electrolyzer, with both the anode and cathode being cobalt ruthenium oxide self-supporting electrodes, each measuring 1*1cm, and the test electrolyte being a 0.5M H2SO4 solution.
[0020] Compared with the prior art, the beneficial effects of the present invention are:
[0021] This invention enables the in-situ growth of catalytic materials on a three-dimensional porous conductive substrate, preparing a self-supporting catalyst that requires no binder and has a larger specific surface area, exposing more active sites and further improving the activity and stability of the material. By adjusting the doping elements, the low electronegativity of cobalt provides electrons to ruthenium, inhibiting the over-oxidation of ruthenium and improving the activity and stability of the catalyst to a certain extent, giving it good performance at high current densities. The hydrothermal method is used for preparation, which is simple and controllable, does not require expensive equipment, and has the potential for large-scale application, and can be widely used in water electrolysis devices. Attached Figure Description
[0022] Figure 1 This is a SEM image of the cobalt-ruthenium oxide self-supporting electrode according to an embodiment of the present invention;
[0023] Figure 2 This is a TEM image of the cobalt-ruthenium oxide self-supporting electrode according to an embodiment of the present invention;
[0024] Figure 3 This is an HRTEM image of the cobalt-ruthenium oxide self-supporting electrode according to an embodiment of the present invention;
[0025] Figure 4 These are the OER polarization curves of the cobalt ruthenium oxide self-supporting electrode of the present invention, the product obtained in the comparative example, and the commercial RuO2 catalyst in acidic electrolyte;
[0026] Figure 5 These are the HER polarization curves of the cobalt-ruthenium oxide self-supporting electrode of the present invention, the product obtained in the comparative example, and the commercial Pt / C catalyst in an acidic electrolyte.
[0027] Figure 6 This is a performance diagram of the water electrolysis device assembled with a cobalt ruthenium oxide self-supporting electrode and the water electrolysis device assembled with a commercial RuO2 catalyst and a commercial Pt / C catalyst according to an embodiment of the present invention, for the complete water electrolysis. Detailed Implementation
[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0029] Example 1:
[0030] A ruthenium cobalt oxide self-supporting electrode is provided, which uses a titanium mesh as a substrate. Ruthenium dioxide nanoparticles are grown in situ on the titanium mesh using a hydrothermal method with an aqueous solution of ruthenium chloride and cobalt chloride. Cobalt atoms are incorporated into the ruthenium dioxide lattice to form a cobalt-doped ruthenium dioxide self-supporting electrode, which can be used as an electrocatalyst for oxygen evolution reaction and hydrogen evolution reaction.
[0031] Method for fabricating ruthenium cobalt oxide self-supporting electrodes
[0032] 1) Place the cut titanium mesh into acetone, ethanol and deionized water in sequence and sonicate for 10 min each; prepare a 18% hydrochloric acid solution, immerse the sonicated titanium mesh in the solution and etch at 90℃ for 15 min; then rinse with ethanol and deionized water in sequence, place in a 60℃ oven and dry for 6 h for later use.
[0033] 2) Prepare 50 ml of 0.5% hydrochloric acid solution; weigh 1.93 mmol of ruthenium chloride and 3.36 mmol of cobalt chloride and add them to the above hydrochloric acid solution, and stir thoroughly at room temperature to dissolve.
[0034] 3) Take a piece of the titanium mesh treated in 1), immerse it in the prepared solution, and then transfer it together to a polytetrafluoroethylene-lined reactor. React at 200°C for 20 hours. After cooling to room temperature, remove the titanium mesh and rinse it alternately with deionized water and ethanol; then dry it in a 60°C oven for 6 hours to obtain the final product.
[0035] Figure 1 This is a SEM image of a cobalt-ruthenium oxide self-supporting electrode, showing that ruthenium dioxide nanoparticles were successfully loaded onto a titanium mesh.
[0036] Figure 2 This is a TEM image of a cobalt-ruthenium oxide self-supporting electrode, showing that ruthenium dioxide nanoparticles are uniformly distributed on a titanium mesh.
[0037] Figure 3 It is an HRTEM with a cobalt-ruthenium oxide self-supporting electrode. The lattice fringe spacing of 0.319 nm corresponds to the Ru(110) plane, and the lattice fringe spacing of 0.325 nm corresponds to the Ti(110) plane.
[0038] Example 2:
[0039] An application of a ruthenium cobalt oxide self-supporting electrode for oxygen evolution reaction, hydrogen evolution reaction, and total water hydrolysis.
[0040] 1) Using a cobalt ruthenium oxide self-supporting electrode as the working electrode, its oxygen evolution and hydrogen evolution performance were tested in a three-electrode system. The working electrode in the three-electrode system was a cobalt ruthenium oxide self-supporting electrode, and the size of each electrode was 1*1cm. The reference electrode and the counter electrode were a reversible hydrogen electrode and a platinum sheet electrode, respectively. The electrolyte used in the test was a 0.5M H2SO4 solution.
[0041] 2) Assemble a complete water splitting device using cobalt-ruthenium oxide self-supporting electrodes. The complete water splitting device is a dual-electrode electrocatalytic electrolyzer, with both the anode and cathode being cobalt-ruthenium oxide self-supporting electrodes, each measuring 1*1cm. The test electrolyte is a 0.5M H2SO4 solution.
[0042] Comparative Example 1:
[0043] 1) The same as step (1) in the preparation method of Example 1 is used to obtain the treated titanium mesh substrate.
[0044] 2) Prepare 50 ml of 0.5% hydrochloric acid solution; weigh 1.93 mmol of ruthenium chloride and add it to the above hydrochloric acid solution, and stir thoroughly at room temperature to dissolve.
[0045] 3) Consistent with step (3) in the preparation method of Example 1, the final product is ruthenium oxide electrocatalyst grown in situ on a titanium mesh.
[0046] Comparative Example 2:
[0047] 1) The same as step (1) in the preparation method of Example 1 is used to obtain the treated titanium mesh substrate.
[0048] 2) Prepare 50 ml of 0.5% hydrochloric acid solution; weigh 3.36 mmol of cobalt chloride and add it to the above hydrochloric acid solution, and stir thoroughly at room temperature to dissolve.
[0049] 3) The preparation method is consistent with step (3) in Example 1, and the final product is a cobalt oxide electrocatalyst grown in situ on a titanium mesh.
[0050] Performance testing:
[0051] 1) A three-electrode system was used, with a 0.5 M H₂SO₄ solution as the electrolyte. The reversible hydrogen electrode and platinum sheet electrode were used as the reference and counter electrodes, respectively, and the prepared electrocatalyst was directly used as the working electrode. Linear sweep voltammetry (LSV) was applied to evaluate the OER performance of the catalyst with IR compensation. The test results are as follows: Figure 4 As shown. In a 0.5M H₂SO₄ electrolyte, an overpotential of 455V can be achieved to reach 1000mA cm⁻¹. -2 The current density and catalytic performance are significantly better than those of the comparative sample and commercial RuO2.
[0052] Its HER catalytic activity was tested in 0.5M H2SO4 electrolyte, and the results are as follows: Figure 5 The required overpotential of 365V can reach 1000mA cm. -2 The current density and catalytic performance are significantly better than those of the comparative ratio and commercial Pt / C.
[0053] 2) The cobalt-ruthenium oxide self-supporting electrode obtained above was assembled into a two-electrode electrolyzer, and its total water splitting performance was tested under acidic conditions. The results are as follows: Figure 6 As shown, only a small voltage of 1.45V is needed to achieve a 10mA cm-wave current. -2 The current density is much lower than that of a commercial electrolytic cell composed of RuO2 and Pt / C (1.50V).
[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A ruthenium cobalt oxide self-supporting electrode, characterized in that: Using a titanium mesh as a substrate, ruthenium dioxide nanoparticles are grown in situ on the titanium mesh in hydrochloric acid aqueous solution of ruthenium chloride and cobalt chloride via a hydrothermal method. Cobalt atoms are incorporated into the ruthenium dioxide lattice to form a cobalt-doped ruthenium dioxide self-supporting electrode, which is used as an electrocatalyst for oxygen evolution reaction and hydrogen evolution reaction. The volume of the hydrochloric acid aqueous solution is 50 ml, the mass fraction is 0.5%, the molar ratio of ruthenium chloride to cobalt chloride is 1:1.74, the concentration of ruthenium chloride is 38.6 mM, and the concentration of cobalt chloride is 67.2 mM. The reaction conditions were 200℃ for 20 h.
2. The method for preparing the ruthenium cobalt oxide self-supporting electrode according to claim 1, characterized in that: 1) Place the cut titanium meshes into the cleaning solution one by one and clean them ultrasonically; immerse the ultrasonically cleaned titanium meshes in hydrochloric acid solution for etching; then rinse them with the cleaning solution one by one and dry them in an oven; 2) Add ruthenium chloride and cobalt chloride to the hydrochloric acid solution and stir thoroughly at room temperature to dissolve; 3) Take a piece of titanium mesh treated in 1), immerse it in the solution in 2), and then transfer it together to a reaction vessel lined with polytetrafluoroethylene for reaction. After cooling to room temperature, remove the titanium mesh, rinse it, and dry it to obtain a ruthenium cobalt oxide self-supporting electrode. The hydrochloric acid solution in step 2) has a volume of 50 ml, a mass fraction of 0.5%, a molar ratio of ruthenium chloride to cobalt chloride of 1:1.74, a concentration of ruthenium chloride of 38.6 mM, and a concentration of cobalt chloride of 67.2 mM. In step 3), the reaction conditions are 200℃ for 20 h.
3. The method for preparing the ruthenium cobalt oxide self-supporting electrode according to claim 2, characterized in that: The titanium mesh in step 1) is sequentially cleaned with acetone, ethanol and deionized water, and then rinsed with ethanol and deionized water after etching.
4. The method for preparing the ruthenium cobalt oxide self-supporting electrode according to claim 2, characterized in that: In step 1), the process involves ultrasonication for 10 min, etching at 90°C for 15 min, drying at 60°C for 6 h, and using a hydrochloric acid solution with a mass fraction of 18%.
5. The method for preparing the ruthenium cobalt oxide self-supporting electrode according to claim 2, characterized in that: In step 3), the mixture is rinsed alternately with deionized water and ethanol, and then dried at 60°C for 6 hours.
6. An application of the ruthenium cobalt oxide self-supporting electrode according to claim 1, or an application of the ruthenium cobalt oxide self-supporting electrode prepared by the preparation method according to any one of claims 2-5, characterized in that: Used in oxygen evolution reaction, hydrogen evolution reaction, or complete decomposition of water.
7. The application according to claim 6, characterized in that, The oxygen evolution or hydrogen evolution performance of the cobalt ruthenium oxide self-supporting electrode is tested in a three-electrode system using the cobalt ruthenium oxide self-supporting electrode as the working electrode, or the cobalt ruthenium oxide self-supporting electrode is assembled into a complete water splitting device.
8. The application according to claim 7, characterized in that: The working electrode in the three-electrode system is a cobalt-ruthenium oxide self-supporting electrode, and each electrode is 1*1cm in size. The reference electrode and the counter electrode are a reversible hydrogen electrode and a platinum sheet electrode, respectively. The electrolyte used in the test is a 0.5M H2SO4 solution.
9. The application according to claim 7, characterized in that: The complete water splitting device is a dual-electrode electrocatalytic electrolyzer, with both the anode and cathode being cobalt ruthenium oxide self-supporting electrodes, each measuring 1*1cm. The test electrolyte is a 0.5M H2SO4 solution.