Carbon supported ruthenium iridium-manganese tetroxide electrocatalyst and application thereof

Abstract

The application discloses a carbon-supported ruthenium-iridium-manganese tetraoxide electrocatalyst and application thereof, and relates to the technical field of electrocatalysis. The carbon-supported ruthenium-iridium-manganese tetraoxide electrocatalyst is formed by in-situ carbonization of glucose to form an amorphous carbon carrier, loading of a ruthenium-iridium bimetallic active component and manganese tetraoxide, and formation of an interface coupling structure of the two. The carbon-supported ruthenium-iridium-manganese tetraoxide electrocatalyst has good conductivity and stability, and has good catalytic activity and stability in an acid electrolytic water anode oxygen evolution reaction.

Description

Technical Field

[0001] This invention relates to the field of electrocatalyst technology, specifically to a carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst and its applications. Background Technology

[0002] Electrolysis of water for hydrogen production is a promising green and sustainable method due to its significant advantages, including a wide availability of raw water, high purity of produced hydrogen, relatively simple preparation process, mild reaction conditions, and clean, pollution-free operation. Currently, proton exchange membrane electrolysis (PEM) technology stands out among various water electrolysis hydrogen production technologies, boasting advantages such as high electrolysis efficiency, compact device structure, and strong adaptability to renewable energy fluctuations, making it a hot research and application area. However, in actual operation, the oxygen evolution catalyst layer on the anode side of the PEM electrolyzer faces severe challenges. Because the oxygen evolution reaction generates a large number of hydrogen ions, the catalyst directly supported on the membrane is exposed to a highly acidic environment for extended periods. Simultaneously, the high oxidation potential exacerbates the risk of catalyst corrosion. Under these harsh operating conditions, the anode oxygen evolution catalyst is easily corroded, leading to reduced activity or even deactivation, severely restricting the large-scale application and development of PEM water electrolysis for hydrogen production. Therefore, developing an anode oxygen evolution catalyst with low overpotential, high catalytic activity, and excellent corrosion resistance is crucial for breakthroughs in PEM water electrolysis for hydrogen production.

[0003] In the field of acidic oxygen evolution catalysts, noble metals ruthenium and iridium, and their oxides, exhibit significant advantages, possessing excellent corrosion resistance and catalytic activity, making them core materials for PEM anode oxygen evolution catalysts. However, ruthenium and iridium resources are scarce and expensive, greatly increasing the cost of PEM hydrogen production technology and severely limiting its large-scale application. To address this challenge, researchers have conducted extensive research on improving the activity of noble metal catalysts and reducing the amount of noble metals used, enhancing catalyst performance through methods such as combining noble metals with other metals and optimizing preparation processes.

[0004] Although the aforementioned existing technologies have improved the acidic oxygen evolution performance of ruthenium-iridium based catalysts to some extent through multi-metal composite or carbon-supported strategies, significant technical limitations remain. Existing noble metal / metal oxide composite carbon-supported catalysts often employ external loading of commercial carbon materials, resulting in weak interactions between the active component and the carbon support. This leads to poor dispersion of the active component and issues such as agglomeration at high temperatures or during the reaction. Furthermore, some preparation methods suffer from cumbersome processes and demanding reaction conditions, making it difficult to meet the practical needs of industrial-scale production. Therefore, developing a simple process that allows for in-situ construction of carbon supports and enables efficient and tight coupling of noble metal bimetals and manganese tetroxide into an electrocatalyst is of significant practical importance for improving the overall performance of acidic oxygen evolution catalysts and reducing preparation and application costs. Summary of the Invention

[0005] This invention addresses the problems of low precious metal utilization, difficulty in balancing activity and stability, and weak bonding between carbon support and active components in existing acidic oxygen evolution electrocatalysts. It provides a carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst, which forms a carbon support through in-situ pyrolysis of glucose, achieving tight coupling between the ruthenium-iridium bimetal and manganese tetroxide. The resulting catalyst exhibits excellent catalytic activity and stability in the acidic oxygen evolution reaction.

[0006] The first aspect of this invention provides a carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst, comprising an amorphous carbon support, a ruthenium-iridium bimetallic active component, and manganese tetroxide. The amorphous carbon support is a carbon material formed by in-situ carbonization of glucose. The ruthenium-iridium bimetallic active component and manganese tetroxide are uniformly dispersed and anchored on the surface and / or in the pores of the carbon material, and an interfacial coupling structure is formed between the ruthenium-iridium bimetallic active component and the manganese tetroxide. The preparation method of the carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst includes: Step S1: Dissolve manganese salt, ruthenium salt and iridium salt in deionized water, add glucose and then sonicate to obtain precursor solution; Step S2: The precursor solution obtained in step S1 is subjected to drying and calcination treatments in sequence, followed by cooling to obtain a black powder; Step S3: The black powder obtained in step S2 is subjected to acid washing, filtration and drying to obtain carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst. In step S2, the drying process is carried out under vacuum conditions, and the parameters of the drying process are as follows: temperature is 50-80℃, and time is 10-15h. In step S2, the calcination treatment is carried out in an air atmosphere, and the parameters of the calcination treatment are as follows: temperature is 200-500℃, heating rate is 1-5℃ / min, and time is 6-7h.

[0007] The preparation principle of the carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst provided by this invention is as follows: using manganese salt, ruthenium salt, and iridium salt as metal precursors, glucose acts as both a carbon source and a gelling agent. Uniform dispersion of each component is achieved through solution mixing and ultrasonic dispersion. During the drying process, glucose and metal ions form a dry gel precursor, thereby avoiding local crystallization and agglomeration of the active components. During calcination, glucose is carbonized in situ to form an amorphous carbon support, and the metal precursors undergo simultaneous oxidation and crystallization to form a ruthenium-iridium bimetallic active component and manganese tetroxide. The two are uniformly dispersed and anchored on the surface and / or pores of the carbon material, and an interfacial coupling structure is formed between the ruthenium-iridium bimetallic active component and manganese tetroxide. Subsequent acid washing further removes unreacted soluble metal salts and acid-soluble byproducts from the system, finally obtaining a carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst composed of an amorphous carbon support, a ruthenium-iridium bimetallic active component, and manganese tetroxide.

[0008] Compared with existing technologies, the carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst prepared in this invention consists of an amorphous carbon support, a ruthenium-iridium bimetallic active component, and manganese tetroxide. The ruthenium-iridium bimetallic active component and manganese tetroxide form an interfacial coupling structure, and are uniformly dispersed and anchored on the surface and / or in the pores of the carbon support. The amorphous carbon support formed by in-situ carbonization of glucose has a relatively tight bond with the active component, which is beneficial to improving the dispersibility of the ruthenium-iridium bimetallic active component and manganese tetroxide, and inhibiting particle agglomeration. The ruthenium-iridium bimetallic active component serves as the active site for the acidic oxygen evolution reaction (OER). Manganese tetroxide can regulate the electronic structure of the ruthenium-iridium bimetallic active component through interfacial coupling, inhibiting excessive oxidation and dissolution of the noble metal and improving the intrinsic activity of the active site. The amorphous carbon support can improve the conductivity of the catalyst and enhance its structural stability, thus enabling the electrocatalyst to exhibit better catalytic performance in the acidic OER.

[0009] More specifically, compared with the prior art, the slow vacuum drying method of the present invention can avoid the problems of local enrichment of metal ions and premature crystallization and agglomeration caused by rapid drying, and ensure that the manganese, ruthenium and iridium metal components are uniformly distributed in the precursor. This provides a high-quality precursor foundation for the in-situ uniform carbonization of glucose and the synchronous regular crystallization of the metal precursor in the subsequent calcination stage. It also ensures that the ruthenium-iridium bimetal and manganese tetroxide can be uniformly dispersed and anchored on the surface and pores of the carbon carrier in the final system, providing a core prerequisite for the two to fully construct a tight interfacial coupling structure and achieve synergistic effect of the components.

[0010] More specifically, the slow heating in step S2 enables the gradual pyrolysis and carbonization of glucose, forming a stable and uniformly porous amorphous carbon support, while avoiding excessive carbon support burn-off and structural collapse. Simultaneously, it drives the uniformly distributed manganese, ruthenium, and iridium metal precursors to undergo stable oxidation and crystallization, precisely generating manganese tetroxide and ruthenium-iridium bimetallic active components. This calcination condition effectively inhibits abnormal growth and agglomeration of active particles, ensuring that the ruthenium-iridium bimetallic active components and manganese tetroxide are uniformly intercalated and anchored on the surface and within the pores of the amorphous carbon support. It also promotes close contact between the two active components, fully constructing a stable heterogeneous interface coupling structure, maximizing the synergistic catalytic advantages of multiple components, and significantly improving the catalyst's structural integrity and acidic oxygen evolution catalytic performance.

[0011] In one possible implementation, in step S1, manganese salt, ruthenium salt, and iridium salt are added in an equimolar ratio.

[0012] Compared with existing technologies, the addition of manganese salt, ruthenium salt and iridium salt in equimolar ratio in step S1 is beneficial to achieve a relatively balanced distribution of each metal component in the precursor system. This promotes the formation of a more sufficient interfacial coupling structure between the ruthenium-iridium bimetallic active component and manganese tetroxide during the subsequent calcination process, further enhancing the synergistic effect between the components and improving the catalytic performance and structural stability of the obtained electrocatalyst.

[0013] In one possible implementation, in step S1, the molar ratio of glucose to manganese salt is (3-5):1.

[0014] Compared with existing technologies, controlling the molar ratio of glucose to manganese salt to (3-5):1 in step S1 is beneficial for balancing the gelation and carbon source effects of glucose. This allows glucose to form a relatively uniform dry gel precursor during drying and an appropriate amount of amorphous carbon support after calcination, thus achieving effective loading of the active component. If the amount of glucose is too low, the dry gel structure may be incomplete and the carbon loading insufficient, which is not conducive to the dispersion of the active component. If the amount of glucose is too high, excessive carbon residue may obscure some active sites, thereby affecting catalytic performance.

[0015] In one possible implementation, in step S1, the ultrasonic treatment is performed at room temperature and the ultrasonic treatment time is 10-30 minutes.

[0016] Compared with existing technologies, the ultrasonic treatment in step S1 at room temperature helps to break the local aggregation state in the solution and promotes the uniform dispersion of manganese salt, ruthenium salt, iridium salt and glucose in the precursor solution, thereby laying the foundation for the formation of the subsequent dry gel precursor and the uniform loading of the final active components on the carbon support.

[0017] In one possible implementation, in step S1, the manganese salt is selected from at least one of manganese chloride, manganese chloride hydrate, manganese nitrate, and manganese nitrate hydrate; the ruthenium salt is selected from at least one of ruthenium chloride and ammonium ruthenate; and the iridium salt is selected from at least one of iridium chloride and ammonium iridium chloroate.

[0018] Compared with existing technologies, selecting at least one of manganese chloride, manganese chloride hydrate, manganese nitrate, and manganese nitrate hydrate as manganese salt, and selecting at least one of ruthenium chloride and ammonium ruthenate as ruthenium salt, and selecting at least one of iridium chloride and ammonium iridium chlorate as iridium salt, is beneficial to ensuring the solubility and reaction compatibility of each metal precursor in the solution system, thereby facilitating the formation of a homogeneous precursor system, and is also beneficial to the formation of the corresponding active components and manganese tetroxide during the subsequent calcination process.

[0019] In one possible implementation, in step S3, the acid washing treatment uses a sulfuric acid solution with a concentration of 0.4-0.6 mol / L, and the parameters of the acid washing treatment are as follows: time ≥ 2h, stirring rate 300-500 r / min.

[0020] Compared with existing technologies, step S3 uses a sulfuric acid solution with a concentration of 0.4-0.6 mol / L for acid washing, and controls the acid washing time to be no less than 2 hours and the stirring rate to be 300-500 r / min. This is beneficial for fully removing unreacted soluble metal salts and acid-soluble byproducts from the system, while reducing the adverse effects on the ruthenium-iridium bimetallic active component, manganese tetroxide, and carbon support structure. The appropriate stirring rate also helps to improve the solid-liquid contact efficiency and avoid particle breakage due to excessive mechanical action.

[0021] The second objective of this invention is to provide an application of the above-mentioned carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst in the oxygen evolution reaction at the anode of water electrolysis.

[0022] Compared with existing technologies, applying the carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst to the oxygen evolution reaction at the anode of water electrolysis can fully leverage the synergistic effect between the amorphous carbon support, the ruthenium-iridium bimetallic active component, and manganese tetroxide, thereby improving the catalytic activity, reaction kinetics, and operational stability of the oxygen evolution reaction. It is particularly suitable for the oxygen evolution process at the anode of water electrolysis under acidic conditions.

[0023] In one possible implementation, the carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst is mixed with a binder and a solvent to form an electrode slurry, which is then coated onto the surface of a conductive substrate to obtain a working electrode.

[0024] Compared with existing technologies, mixing the carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst with binders and solvents to form an electrode slurry and coating it onto the surface of a conductive substrate is beneficial for effectively loading the catalyst onto the electrode surface, forming a catalytic layer with good adhesion and conductive contact, thereby improving the catalytic efficiency and stability of the electrode in the oxygen evolution reaction at the anode of water electrolysis.

[0025] Specifically, the above application involves mixing the carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst with a binder and solvent to prepare an electrode slurry, which is then coated onto the surface of a conductive substrate to obtain a working electrode. In electrocatalytic performance testing, a three-electrode testing system can be used, with an Hg / Hg₂SO₄ electrode as the reference electrode, a carbon rod as the counter electrode, and a 0.5 mol / L sulfuric acid solution as the electrolyte, to evaluate the oxygen evolution reaction performance of the working electrode. The carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst can also be used as an anode oxygen evolution active component in the proton exchange membrane water electrolysis hydrogen production process.

[0026] Compared with the prior art, the present invention has the following beneficial effects: (1) By optimizing and controlling the calcination process parameters of the precursor, relying on the appropriate calcination temperature, slow heating rate and constant temperature duration, the glucose is carbonized in situ to form an amorphous carbon carrier and realize the reaction rhythm of synchronous oxidation and crystallization of the metal precursor. The carbon carrier is formed and the active component is crystallized in a step-by-step manner, effectively suppressing the abnormal growth and agglomeration of active particles and the carbon carrier burn-off and collapse problem, ensuring that the ruthenium-iridium bimetal and manganese tetroxide are uniformly anchored and tightly coupled, and constructing a stable heterogeneous interface structure.

[0027] (2) The overall preparation process of the carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst of the present invention is relatively simple and the reaction conditions are mild. No complicated equipment is required. The target product can be obtained by solution mixing, ultrasonic treatment, drying, calcination and acid washing. At the same time, glucose has the functions of both carbon source and gelling agent. The raw materials are readily available, which helps to reduce the preparation cost of the catalyst and has certain prospects for large-scale preparation and application. Attached Figure Description

[0028] Figure 1 This is a scanning electron microscope (SEM) image of the catalyst RuIr–Mn3O4 / C prepared in Example 1 of this invention. Figure 2 This is a high-magnification transmission electron microscope (HRTEM) image of the catalyst RuIr-Mn3O4 / C prepared in Example 1 of this invention. Figure 3 X-ray diffraction (XRD) pattern of the catalyst RuIr-Mn3O4 / C prepared in Example 1 of this invention; Figure 4The polarization curves of the catalysts prepared in Example 1 and Comparative Examples 1-2 of this invention and commercially available RuO2 in the application examples of the oxygen evolution reaction of acidic water electrolysis are shown. Figure 5 The voltage versus time curve of the catalyst RuIr–Mn3O4 / C prepared in Example 1 of this invention under constant current during the oxygen evolution reaction of acidic water electrolysis. Detailed Implementation

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] 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. Every smaller range between any stated value or intermediate value within a stated range, and 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.

[0031] 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 obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0032] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the room temperature in the present application is 20-30℃.

[0033] Example 1

[0034] This embodiment provides a carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst, which is prepared by the following method: S1. Weigh 0.1 mmol of anhydrous MnCl2 in a beaker, dissolve it in 3 mL of deionized water, and stir magnetically until completely dissolved. Then, add 1 mL of 0.1 mol / L RuCl3 aqueous solution, 1 mL of 0.1 mol / L IrCl3 aqueous solution, and 0.3 mmol of glucose. Continue to stir magnetically for 30 min until the system is homogeneous. Then, place it in an ultrasonic cleaner and sonicate at room temperature for 10 min to obtain a homogeneous precursor solution. S2. Transfer all the precursor solution obtained in step S1 to a ceramic boat, place the ceramic boat in a vacuum drying oven, and vacuum dry at 60°C for 12 hours to obtain a uniformly composed dry gel precursor. S3. Place the ceramic boat containing the dry gel precursor in a muffle furnace, heat it to 350°C at a heating rate of 2°C / min in air atmosphere, and keep it at that temperature for 6 hours. After calcination, allow it to cool naturally to room temperature to obtain a black powder. S4. Transfer the black powder obtained in step S3 to a beaker, add 0.5 mol / L H2SO4 solution, place it on a magnetic stirrer and stir at a rate of 400 r / min for 2 h to remove unreacted metal salt precursors and acid-soluble impurities. S5. The solid-liquid mixture after acid washing in step S4 is filtered. The resulting filter residue is transferred to an oven and dried overnight at 60°C. After drying, the solid is taken out and ground into fine powder in an agate mortar to obtain carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst, denoted as RuIr-Mn3O4 / C.

[0035] The carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst prepared in this embodiment was observed by scanning electron microscopy (SEM), and the results are as follows: Figure 1 As shown. By Figure 1 It is evident that the catalyst exhibits a nanoscale particulate structure. Figure 2 Here is a high-magnification transmission electron microscope (HRTEM) image of the catalyst RuIr-Mn3O4 / C prepared in this embodiment; Figure 3 X-ray diffraction (XRD) pattern of the catalyst RuIr-Mn3O4 / C prepared in this embodiment.

[0036] Depend on Figure 2 It can be seen that the catalyst RuIr-Mn3O4 / C prepared in this embodiment contains an amorphous carbon matrix and simultaneously exhibits characteristic lattice fringes corresponding to metallic Ru, metallic Ir, and Mn3O4; ruthenium-iridium bimetallic grains and manganese tetroxide grains are in close contact to form a heterogeneous interface, successfully constructing an interfacial coupling structure, and the active components are uniformly loaded on the carbon support. Figure 3 It can be seen that the catalyst RuIr-Mn3O4 / C prepared in this embodiment has characteristic diffraction peaks of Mn3O4, Ru and Ir, and no obvious impurity peaks are observed, indicating that the carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst was successfully prepared.

[0037] Example 2

[0038] This embodiment provides a carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst, which is prepared by the following method: S1. Weigh 0.1 mmol of anhydrous MnCl2 in a beaker, dissolve it in 3 mL of deionized water, and stir magnetically until completely dissolved. Then, add 1 mL of 0.1 mol / L RuCl3 aqueous solution, 1 mL of 0.1 mol / L IrCl3 aqueous solution, and 0.3 mmol of glucose. Continue to stir magnetically for 30 min until the system is homogeneous. Then, place it in an ultrasonic cleaner and sonicate at room temperature for 20 min to obtain a homogeneous precursor solution. S2. Transfer all the precursor solution obtained in step S1 to a ceramic boat, place the ceramic boat in a vacuum drying oven, and vacuum dry at 80°C for 10 h to obtain a uniformly composed dry gel precursor. S3. Place the ceramic boat containing the dry gel precursor in a muffle furnace, heat it to 450°C at a heating rate of 5°C / min in air atmosphere, and keep it at that temperature for 6.5 hours. After calcination, allow it to cool naturally to room temperature to obtain a black powder. S4. Transfer the black powder obtained in step S3 to a beaker, add 0.6 mol / L H2SO4 solution, place it on a magnetic stirrer and stir at a rate of 400 r / min for 2 h to remove unreacted metal salt precursors and acid-soluble impurities. S5. The solid-liquid mixture after acid washing in step S4 is filtered. The resulting filter residue is transferred to an oven and dried overnight at 60°C. After drying, the solid is taken out and ground into fine powder in an agate mortar to obtain carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst, denoted as RuIr-Mn3O4 / C.

[0039] Example 3

[0040] This embodiment provides a carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst, which is prepared by the following method: S1. Weigh 0.1 mmol of manganese nitrate into a beaker, dissolve it in 3 mL of deionized water, and stir magnetically until completely dissolved. Then, add 1 mL of 0.1 mol / L ammonium chlororuthenate aqueous solution and 1 mL of 0.1 mol / L ammonium chloroiridate aqueous solution, followed by 0.3 mmol of glucose. Continue stirring magnetically for 30 min until the system is homogeneous. Then, place the system in an ultrasonic cleaner and sonicate at room temperature for 30 min to obtain a homogeneous precursor solution. S2. Transfer all the precursor solution obtained in step S1 to a ceramic boat, place the ceramic boat in a vacuum drying oven, and vacuum dry at 50°C for 15 hours to obtain a uniformly composed dry gel precursor. S3. Place the ceramic boat containing the dry gel precursor in a muffle furnace, heat it to 500°C at a heating rate of 3°C / min in air atmosphere, and keep it at that temperature for 6 hours. After calcination, allow it to cool naturally to room temperature to obtain a black powder. S4. Transfer the black powder obtained in step S3 to a beaker, add 0.4 mol / L H2SO4 solution, place it on a magnetic stirrer and stir at a rate of 400 r / min for 2 h to remove unreacted metal salt precursors and acid-soluble impurities. S5. The solid-liquid mixture after acid washing in step S4 is filtered. The resulting filter residue is transferred to an oven and dried overnight at 60°C. After drying, the solid is taken out and ground into fine powder in an agate mortar to obtain carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst, denoted as RuIr-Mn3O4 / C.

[0041] Example 4

[0042] This embodiment provides a carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst, which is prepared by the following method: S1. Weigh 0.1 mmol of manganese nitrate into a beaker, dissolve it in 3 mL of deionized water, and stir magnetically until completely dissolved. Then, add 1 mL of 0.1 mol / L ammonium chlororuthenate aqueous solution, 1 mL of 0.1 mol / L ammonium chloroiridate aqueous solution, and 0.4 mmol of glucose. Continue to stir magnetically for 30 min until the system is homogeneous. Then, place it in an ultrasonic cleaner and sonicate at room temperature for 30 min to obtain a homogeneous precursor solution. S2. Transfer all the precursor solution obtained in step S1 to a ceramic boat, place the ceramic boat in a vacuum drying oven, and vacuum dry at 60°C for 12 hours to obtain a uniformly composed dry gel precursor. S3. Place the ceramic boat containing the dry gel precursor in a muffle furnace, heat it to 200°C at a heating rate of 1°C / min in air atmosphere, and keep it at that temperature for 7 hours. After calcination, allow it to cool naturally to room temperature to obtain a black powder. S4. Transfer the black powder obtained in step S3 to a beaker, add 0.5 mol / L H2SO4 solution, place it on a magnetic stirrer and stir at a rate of 500 r / min for 3 h to remove unreacted metal salt precursors and acid-soluble impurities. S5. The solid-liquid mixture after acid washing in step S4 is filtered. The resulting filter residue is transferred to an oven and dried overnight at 60°C. After drying, the solid is taken out and ground into fine powder in an agate mortar to obtain carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst, denoted as RuIr-Mn3O4 / C.

[0043] Example 5

[0044] This embodiment provides a carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst, which is prepared by the following method: S1. Weigh 0.1 mmol of manganese nitrate into a beaker, dissolve it in 3 mL of deionized water, and stir magnetically until completely dissolved. Then, add 1 mL of 0.1 mol / L ammonium chlororuthenate aqueous solution, 1 mL of 0.1 mol / L ammonium chloroiridate aqueous solution, and 0.5 mmol of glucose. Continue to stir magnetically for 30 min until the system is homogeneous. Then, place it in an ultrasonic cleaner and sonicate at room temperature for 30 min to obtain a homogeneous precursor solution. S2. Transfer all the precursor solution obtained in step S1 to a ceramic boat, place the ceramic boat in a vacuum drying oven, and vacuum dry at 60°C for 12 hours to obtain a uniformly composed dry gel precursor. S3. Place the ceramic boat containing the dry gel precursor in a muffle furnace, heat it to 350°C at a heating rate of 2°C / min in air atmosphere, and keep it at that temperature for 6.5 hours. After calcination, allow it to cool naturally to room temperature to obtain a black powder. S4. Transfer the black powder obtained in step S3 to a beaker, add 0.5 mol / L H2SO4 solution, place it on a magnetic stirrer and stir at a rate of 300 r / min for 2 h to remove unreacted metal salt precursors and acid-soluble impurities. S5. The solid-liquid mixture after acid washing in step S4 is filtered. The resulting filter residue is transferred to an oven and dried overnight at 60°C. After drying, the solid is taken out and ground into fine powder in an agate mortar to obtain carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst, denoted as RuIr-Mn3O4 / C.

[0045] Comparative Example 1 This comparative example provides a carbon-supported iridium-manganese tetroxide comparative catalyst, which differs from Example 1 only in that RuCl3 aqueous solution is not added in step S1, as detailed below: S1. Weigh 0.1 mmol of anhydrous MnCl2 in a beaker, dissolve it in 3 mL of deionized water, stir magnetically until completely dissolved, add 1 mL of 0.1 mol / L IrCl3 aqueous solution, then add 0.3 mmol of glucose, continue to stir magnetically for 30 min until the system is mixed evenly, and then place it in an ultrasonic cleaner and sonicate at room temperature for 10 min to obtain a homogeneous precursor solution. S2. Transfer all the precursor solution obtained in step S1 to a ceramic boat, place the ceramic boat in a vacuum drying oven, and vacuum dry at 60°C for 12 hours to obtain a uniformly composed dry gel precursor. S3. Place the ceramic boat containing the dry gel precursor in a muffle furnace, heat it to 350°C at a heating rate of 2°C / min in air atmosphere, and keep it at that temperature for 6 hours. After calcination, allow it to cool naturally to room temperature to obtain a black powder. S4. Transfer the black powder obtained in step S3 to a beaker, add 0.5 mol / L H2SO4 solution, place it on a magnetic stirrer and stir at a rate of 400 r / min for 2 h to remove unreacted metal salt precursors and acid-soluble impurities. S5. The solid-liquid mixture after acid washing in step S4 is filtered. The resulting filter residue is transferred to an oven and dried overnight at 60°C. After drying, the solid is taken out and ground into fine powder in an agate mortar to obtain a carbon-supported iridium-manganese tetroxide comparative catalyst, denoted as Ir-Mn3O4 / C.

[0046] Comparative Example 2 This comparative example provides a carbon-supported ruthenium-manganese tetroxide comparative catalyst, which differs from Example 1 only in that an IrCl3 aqueous solution is not added in step S1, as detailed below: S1. Weigh 0.1 mmol of anhydrous MnCl2 in a beaker, dissolve it in 3 mL of deionized water, stir magnetically until completely dissolved, add 1 mL of 0.1 mol / L RuCl3 aqueous solution, then add 0.3 mmol of glucose, continue to stir magnetically for 30 min until the system is mixed evenly, and then place it in an ultrasonic cleaner and sonicate at room temperature for 10 min to obtain a homogeneous precursor solution. S2. Transfer all the precursor solution obtained in step S1 to a ceramic boat, place the ceramic boat in a vacuum drying oven, and vacuum dry at 60°C for 12 hours to obtain a uniformly composed dry gel precursor. S3. Place the ceramic boat containing the dry gel precursor in a muffle furnace, heat it to 350°C at a heating rate of 2°C / min in air atmosphere, and keep it at that temperature for 6 hours. After calcination, allow it to cool naturally to room temperature to obtain a black powder. S4. Transfer the black powder obtained in step S3 to a beaker, add 0.5 mol / L H2SO4 solution, place it on a magnetic stirrer and stir at a rate of 400 r / min for 2 h to remove unreacted metal salt precursors and acid-soluble impurities. S5. The solid-liquid mixture after acid washing in step S4 is filtered. The resulting filter residue is transferred to an oven and dried overnight at 60°C. After drying, the solid is taken out and ground into fine powder in an agate mortar to obtain carbon-supported ruthenium-manganese tetroxide comparative catalyst, denoted as Ru-Mn3O4 / C.

[0047] Comparative Example 3 This comparative example provides a carbon-supported ruthenium-manganese tetroxide comparative catalyst, which differs from Example 1 only in steps S2 and S3. Steps S2 and S3 in this comparative example are as follows: S2. Place the precursor solution obtained in step S1 in a forced-air drying oven and dry it rapidly at 120°C for 3 hours to obtain a slightly agglomerated, dense and non-uniform precursor block. S3. Place the precursor block in a muffle furnace and heat it to 350°C at a heating rate of 10°C / min in an air atmosphere, and hold it at that temperature for 6 hours.

[0048] Observations revealed that the carbon-supported ruthenium-manganese tetroxide comparative catalyst prepared in Comparative Example 3 suffered from component segregation due to rapid drying in the early stage, coupled with rapid calcination leading to rapid grain growth and severe agglomeration of active particles, making it difficult for the ruthenium-iridium bimetal and manganese tetroxide to form a tight and uniform interfacial coupling structure.

[0049] As can be seen from this comparative example, the slow vacuum drying method used in this invention is a prerequisite for ensuring the uniform distribution of precursor components, which can avoid the problem of metal component segregation and agglomeration from the source and provide a uniform precursor template for subsequent regular crystallization. Gradient slow calcination is the core guarantee for constructing an excellent heterogeneous interface and a complete carbon support structure, which can accurately match the carbonization and crystallization reaction rates and realize the simultaneous completion of carbon support formation, active component crystallization, and heterogeneous interface coupling.

[0050] Application examples The electrocatalytic performance of the catalyst prepared in this invention in the oxygen evolution reaction at the anode of acidic water electrolysis was evaluated using a three-electrode system. The RuIr-Mn3O4 / C catalyst prepared in Example 1, the Ir-Mn3O4 / C catalyst prepared in Comparative Example 1, the Ru-Mn3O4 / C catalyst prepared in Comparative Example 2, and commercially available RuO2-coated carbon paper were used as working electrodes, a carbon rod as the counter electrode, a saturated Hg / Hg2SO4 electrode as the reference electrode, and a 0.5 mol / L H2SO4 solution as the electrolyte.

[0051] Before testing, argon gas was introduced into the electrolyte for 30 minutes. The electrode was activated using cyclic voltammetry (CV) in the range of 0.8V-1.5V (vs. RHE) at a scan rate of 50mV / s for 40 cycles until the electrode reached a stable state.

[0052] After activation, oxygen evolution performance was tested using linear sweep voltammetry (LSV) in the range of 0.8V–1.5V (vs. RHE) at a scan rate of 5 mV / s. The overpotential was defined as 1.23V relative to the reversible hydrogen electrode and a current density of 10 mA / cm². 2 The difference in potential was measured over time. Figure 4The following figures illustrate the oxygen evolution polarization curves of the RuIr-Mn3O4 / C catalyst prepared in Example 1, the Ir-Mn3O4 / C catalyst prepared in Comparative Example 1, the Ru-Mn3O4 / C catalyst prepared in Comparative Example 2, and commercially available RuO2 in acidic water electrolysis in 0.5 mol / L H2SO4 solution. Figure 4 It is evident that the overpotential of the RuIr-Mn3O4 / C catalyst in the acidic oxygen evolution reaction is significantly superior to that of the Ir-Mn3O4 / C catalyst, the Ru-Mn3O4 / C catalyst, and commercially available RuO2.

[0053] The stability of the RuIr-Mn3O4 / C catalyst prepared in Example 1 was tested. After CV activation, the constant current program was switched to 1.4 mA, and the test time was 100 h. Figure 5 The potential-time curve of the RuIr-Mn3O4 / C catalyst under constant current conditions is shown. Figure 5 It can be seen that the potential of the catalyst did not change significantly during the 100-hour test, indicating that it has good oxygen evolution stability.

[0054] The results above show that the carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst (RuIr-Mn3O4 / C) provided by the present invention exhibits good electrocatalytic performance in the oxygen evolution reaction at the anode of acidic water electrolysis.

[0055] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst, characterized in that, The catalyst comprises an amorphous carbon support, a ruthenium-iridium bimetallic active component, and manganese tetroxide. The amorphous carbon support is a carbon material formed by in-situ carbonization of glucose. The ruthenium-iridium bimetallic active component and manganese tetroxide are uniformly dispersed and anchored on the surface and / or in the pores of the carbon material, and an interfacial coupling structure is formed between the ruthenium-iridium bimetallic active component and manganese tetroxide. The preparation method of the carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst includes: Step S1: Dissolve manganese salt, ruthenium salt and iridium salt in deionized water, add glucose and then sonicate to obtain precursor solution; Step S2: The precursor solution obtained in step S1 is subjected to drying and calcination treatments in sequence, followed by cooling to obtain a black powder; Step S3: The black powder obtained in step S2 is subjected to acid washing, filtration and drying to obtain carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst. In step S2, the drying process is carried out under vacuum conditions, and the parameters of the drying process are as follows: temperature is 50-80℃, and time is 10-15h. In step S2, the calcination treatment is carried out in an air atmosphere, and the parameters of the calcination treatment are as follows: temperature is 200-500℃, heating rate is 1-5℃ / min, and time is 6-7h.

2. The carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst according to claim 1, characterized in that, In step S1, manganese salt, ruthenium salt, and iridium salt are added in an equimolar ratio.

3. The carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst according to claim 1 or 2, characterized in that, In step S1, the molar ratio of glucose to manganese salt is (3-5):

1.

4. The carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst according to claim 1, characterized in that, In step S1, the ultrasonic treatment is performed at room temperature and the ultrasonic treatment time is 10-30 minutes.

5. The carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst according to claim 1 or 2, characterized in that, In step S1, the manganese salt is selected from at least one of manganese chloride, manganese chloride hydrate, manganese nitrate, and manganese nitrate hydrate; the ruthenium salt is selected from at least one of ruthenium chloride and ammonium ruthenate; and the iridium salt is selected from at least one of iridium chloride and ammonium iridium chlorate.

6. The carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst according to claim 1, characterized in that, In step S3, the acid washing treatment uses a sulfuric acid solution with a concentration of 0.4-0.6 mol / L, and the parameters of the acid washing treatment are as follows: time ≥ 2h, stirring rate 300-500r / min.

7. The application of a carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst according to any one of claims 1-6 in the oxygen evolution reaction at the anode of water electrolysis.

8. The application according to claim 7, characterized in that, The carbon-supported ruthenium-iridium-manganese tetroxide electrocatalyst is mixed with a binder and a solvent to form an electrode slurry, which is then coated onto the surface of a conductive substrate to obtain a working electrode.

Images