High-entropy pem anode catalyst, preparation method and application thereof

Abstract

This invention belongs to the field of oxygen evolution reaction (OER) catalytic materials technology, specifically relating to a high-entropy PEM anode catalyst, its preparation method, and its application. This invention uses a non-precious metal Co3O4 material as a substrate, and forms a high-entropy structure by in-situ doping of B, Mn, Mo, and W into Co3O4 through electrodeposition. Based on the inherent mild reaction characteristics and uniform deposition features of the electrodeposition process, this invention achieves uniform mixing of the above elements at the atomic scale and in-situ doping on the catalyst substrate. This not only enhances the catalytic activity and stability of the catalyst under acidic conditions but also avoids dependence on high-cost iridium, significantly reducing the cost of OER catalysts. This invention solves the problems of insufficient structural stability, poor catalytic performance, and high cost due to strong dependence on iridium in existing OER catalysts under acidic conditions with high oxidation potentials, and has high market application prospects.

Description

Technical Field

[0001] This invention belongs to the field of oxygen evolution reaction catalytic materials technology, specifically relating to a high-entropy PEM anode catalyst, its preparation method, and its application. Background Technology

[0002] Hydrogen energy, as a clean, efficient, and renewable energy form, boasts advantages such as zero carbon emissions, high energy density, and diverse sources, and is widely considered a key component in building a future sustainable energy system. Among these technologies, electrochemical water splitting for hydrogen production has become an important route for the large-scale production of high-purity hydrogen due to its high efficiency and environmental friendliness, and has been widely applied in industrial hydrogen production. Based on the pH value of the electrolyte, water electrolysis technology can be divided into three categories: acidic, neutral, and alkaline. Compared to alkaline water electrolysis devices, acidic proton exchange membrane electrolyzers (PEMWEs) exhibit significant advantages in industrial applications: they can achieve rapid proton conduction, improve system conductivity, and effectively reduce ohmic losses. These characteristics enable PEMWEs to operate stably at higher current densities, making them more suitable for efficient and integrated hydrogen energy systems.

[0003] In PEMWE (Potentially Oriented Metal-Enhanced Electrocatalysts), the inherent high overpotential and strongly acidic corrosive environment of the oxygen evolution reaction (OER) pose a severe challenge to the long-term stability of catalysts. Currently, rutile IrO2 is one of the few highly active OER catalysts that can operate stably in this environment for extended periods. However, iridium's low crustal abundance and the need to improve its intrinsic activity result in high costs, making reducing PEM technology's dependence on iridium an urgent requirement for the development of the hydrogen energy industry. Therefore, developing low-cost, high-efficiency electrocatalysts is crucial for advancing the commercialization of PEM.

[0004] Among numerous candidate materials, high-entropy materials exhibit certain OER catalytic activity in acidic media and can remain stable, making them one of the most promising material systems to replace noble metal catalysts. However, the preparation conditions for high-entropy materials are demanding, requiring temperatures above 800°C or even thousands of degrees Celsius. These extreme synthesis conditions greatly limit the widespread application of high-entropy materials. Furthermore, under acidic conditions with high oxidation potentials and pH values ​​of 2–3, their structural stability is insufficient, leading to easy dissolution or deactivation, resulting in current performance falling far short of practical application requirements. Therefore, designing simple and convenient experimental methods for synthesizing high-entropy materials and improving the OER activity and operational stability of non-noble metal acidic catalysts remains a core challenge in this field. Summary of the Invention

[0005] To address the problems of insufficient structural stability, poor catalytic performance, and high cost due to strong dependence on iridium in existing OER catalysts under strong oxidizing and acidic conditions, this invention aims to provide a high-entropy PEM anode catalyst, its preparation method, and its application. This invention uses non-precious metal Co3O4 as a substrate and forms a high-entropy structure by in-situ doping of B, Mn, Mo, and W in Co3O4 through electrodeposition. This not only enhances the catalytic activity and stability of the catalyst under acidic conditions but also avoids dependence on high-cost iridium, greatly reducing the cost of OER catalysts.

[0006] Based on the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a high-entropy PEM anode catalyst, comprising a titanium felt and a Co3O4 layer doped with B, Mn, Mo, and W elements grown in situ on the titanium felt, wherein the B, Mn, Mo, and W elements are uniformly doped in the Co3O4 at the atomic scale; the Co content in the Co3O4 layer is 95-96 wt%, the B doping amount is 0.2-0.3 wt%, the Mn doping amount is 1.1-1.2 wt%, the Mo doping amount is 1.5-1.6 wt%, and the W doping amount is 1.6-1.7 wt%.

[0007] Secondly, the present invention provides a method for preparing the above-mentioned high-entropy PEM anode catalyst, comprising the following steps: S1: Borate, manganese salt, molybdate and tungstate are added to a homogeneous cobalt nitrate solution to form a mixture, wherein the concentration of cobalt nitrate in the mixture is 0.19–0.21 M; the concentrations of borate, manganese salt, molybdate and tungstate in the mixture are all 0.0019–0.0021 M. S2: Using the mixture prepared in S1 as the electrolyte, titanium felt as the working electrode, and carbon rod as the counter electrode, electrodeposition is performed. The resulting precipitate is denoted as BMnMoW-Co(OH)2. S3: The high-entropy PEM anode catalyst is obtained by washing the BMnMoW-Co(OH)2 prepared in step S2 and calcining it in an inert atmosphere.

[0008] This invention utilizes the inherent mild reaction characteristics and uniform deposition features of the electrodeposition process to achieve uniform mixing of multiple elements such as B, Mn, Mo, and W at the atomic scale, thereby preparing materials with high-entropy structures. This technology, by uniformly dispersing multiple metal sources in an electrolyte, only requires the application of voltage to drive the co-deposition reaction, avoiding the high-temperature conditions required for the synthesis of traditional high-entropy materials. This significantly simplifies the preparation process, reduces energy consumption and equipment requirements, and offers outstanding advantages such as ease of operation, mild conditions, and suitability for large-scale scalability.

[0009] Preferably, the molar concentrations of borate, manganese salt, molybdate, and tungstate in the mixture are all 0.5% to 2% of cobalt nitrate.

[0010] When the molar concentrations of borate, manganese salt, molybdate, and tungstate in the mixture are all 1% of cobalt nitrate, the prepared BMnMoW(1%)-Co3O4 exhibits a high molar concentration at 100 mA cm⁻¹. -2 It exhibits the lowest overpotential of 397 mV at the given current density, demonstrating superior electrocatalytic activity.

[0011] Preferably, the borate is at least one of sodium metaborate and sodium borate; the manganese salt is at least one of potassium permanganate and potassium manganate; the molybdate is at least one of sodium molybdate, potassium molybdate, and ammonium tetramolybdate; and the tungstate is at least one of sodium tungstate, sodium metatungstate, and potassium tungstate.

[0012] Preferably, the electrodeposition potential is -0.9 to -1.1 V, and the deposition time is 900 to 1100 s.

[0013] Preferably, the washing in step S3 includes rinsing BMnMoW-Co(OH)2 sequentially with ultrapure water and anhydrous ethanol.

[0014] Preferably, the calcination heating rate is 4-6℃ / min, the calcination temperature is 330-370℃, and the calcination time is 180-220min.

[0015] Preferably, the inert atmosphere is a nitrogen atmosphere.

[0016] Thirdly, the present invention provides the application of the above-mentioned high-entropy PEM anode catalyst in the oxygen evolution reaction of water electrolysis.

[0017] Furthermore, using a three-electrode testing system with a high-entropy PEM anode catalyst as the working electrode, a calomel electrode as the reference electrode, and a platinum sheet as the counter electrode, an overpotential of 10 mA cm⁻¹ was achieved in 0.5 M H₂SO₄ electrolyte at an overpotential not exceeding 253 mV. -2 The current density at 25°C; the activation energy of the high-entropy PEM anode catalyst is not higher than 1.56 kJ mol. -1 ; The high-entropy PEM anode catalyst in the PEM electrolyzer operates at 100 mA cm⁻¹. -2 It can operate continuously and stably for at least 560 hours at the specified current density.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention selects non-noble metal Co3O4 as the main electrocatalyst material and effectively modulates its electronic structure through in-situ doping of multiple elements, thereby enhancing the intrinsic catalytic activity and reaction stability of the catalyst's active sites. To further improve the overall OER performance of the catalyst, this invention utilizes the mild and uniform characteristics of the electrodeposition process. A Co3O4 active layer is grown in situ on a conductive titanium felt substrate by electrodeposition, and multiple highly active and stable elements (B, Mn, Mo, and W) are co-doped to form a high-entropy composite material, enhancing the catalytic activity and stability of the material in acidic environments. This in-situ doping of multiple elements can increase the entropy value and disorder of the material while maintaining the original stable structure of Co3O4, effectively optimizing insufficient active sites, improving catalytic performance, and comprehensively enhancing its intrinsic activity in acidic media. This invention provides a new technical approach for designing low-cost, high-performance transition metal-based high-entropy acidic OER catalysts in acidic media.

[0019] This invention utilizes the inherent mild reaction characteristics and uniform deposition properties of the electrodeposition process to achieve uniform mixing of multiple elements such as B, Mn, Mo, and W at the atomic scale, thereby preparing materials with high-entropy structures. This technology, by uniformly dispersing multiple metal sources in an electrolyte, only requires the application of voltage to drive the co-deposition reaction, avoiding the high-temperature conditions required for traditional high-entropy material synthesis. This significantly simplifies the preparation process, reduces energy consumption and equipment requirements, and offers outstanding advantages such as ease of operation, mild conditions, and ease of large-scale scalability. It substantially reduces the synthesis cost of high-entropy materials, decreases reliance on high-temperature equipment, broadens the applicability of material preparation, and provides a feasible technical path for the widespread application of high-performance high-entropy materials.

[0020] The BMnMoW-Co3O4 material prepared by combining in-situ electrodeposition growth with a high-entropy strategy exhibits excellent catalytic performance in actual OER catalysis: in a three-electrode system with 0.5 M H2SO4 electrolyte, an overpotential of only 253 mV is required to reach 10 mA cm⁻¹. -2 The current density is 10 mA cm⁻¹ at 25 °C, while undoped Co₃O₄ requires an overpotential of 367 mV to reach 10 mA cm⁻¹. -2(25 ℃) Current density. Further investigation into the influence of elemental doping on the acidic OER performance of Co3O4 revealed that high-entropy materials possess higher electrochemical active area and conductivity. To further illustrate the kinetic characteristics of the electrode reaction, in-situ electrochemical impedance spectroscopy (EIS) tests were performed on BMnMoW-Co3O4 and Co3O4. In 0.5 M H2SO4 solution, the Rct of BMnMoW-Co3O4 was much smaller than that of Co3O4, and the rate of Rct decreasing with potential was much faster than that of Co3O4, indicating that its electronic conductivity was higher than that of Co3O4. This suggests that B, Mn, Mo, and W doping can accelerate the proton transport rate during the electrochemical oxygen reduction reaction, significantly improving the kinetic activity of Co3O4 materials.

[0021] The high-entropy BMnMoW-Co3O4 material exhibits excellent stability in actual catalytic processes. Co3O4 and BMnMoW-Co3O4 are reacted at 10 mA cm⁻¹. -2 (25 ℃) Constant current stability operation was performed. BMnMoW-Co3O4 could operate at constant current for more than 180 h, while Co3O4 was deactivated after 60 h under the same conditions. This shows that multi-metal doping can also effectively improve the stability of Co3O4 under acidic conditions.

[0022] Currently, most acidic OER catalysts remain at the laboratory three-electrode stage. This invention, based on the excellent acidic OER activity and stability of the BMnMoW-Co3O4 catalyst in a three-electrode system, further evaluates its potential in practical water electrolysis (PEMWE). Using 40% Pt / C as the cathode catalyst, BMnMoW-Co3O4 as the anolyte catalyst, and Nafion 117 as the proton transport membrane, its PEM performance was measured at 80°C. The polarization curves show that the BMnMoW-Co3O4 electrolyzer operates at 1 A cm⁻¹. -2 The required current density is only 2.25V. Furthermore, time-potential measurements were performed using BMnMoW-Co3O4||Pt / C to evaluate the long-term stability of its PEM electrolyzer. The BMnMoW-Co3O4-based electrolyzer can operate at 100mA cm⁻¹. -2 It can operate stably for 560 hours under the specified current density.

[0023] This invention provides a simple process for water splitting under acidic conditions, suitable for large-scale production, effectively reducing dependence on the precious metal Ir and lowering the preparation cost of the catalyst. At the same time, it has excellent electrocatalytic oxygen evolution performance and stability, and has the potential for industrial application of green hydrogen. Attached Figure Description

[0024] Figure 1 Here is the XRD pattern of the product from Example 1; Figure 2 This is an ICP-MS elemental composition diagram of the product in Example 1; Figure 3 This is a comparison chart of the performance of the product with different element ratios in Example 1; Figure 4 This is a performance comparison chart of Example 1 and the comparative example; Figure 5 This is a comparison diagram of Example 1 and non-high-entropy materials; Figure 6 This is a performance comparison chart of Example 1 and IrO2 with the same loading amount; Figure 7 The diagram shows the double-layer capacitance of the product in Example 1 and Comparative Example 5; Figure 8 The activation energy diagrams are for the product of Example 1 and Comparative Example 5. Figure 9 The in-situ impedance test diagrams are for the product of Example 1 and Comparative Example 5. Figure 10 The graphs show the stability test results of the product in Example 1 and Comparative Example 5. Figure 11 The graphs show the performance of the product from Example 1 and Comparative Example 5 in a PEM electrolyzer. Figure 12 The graphs show the stability test results of the PEM electrolyzer for Example 1 and Comparative Example 5. Detailed Implementation

[0025] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Unless otherwise specified, the experimental methods used in the embodiments are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available. Example 1

[0026] This embodiment provides a high-entropy PEM anode catalyst, which is prepared by in-situ electrodeposition of B, Mn, Mo, and W elements in cobalt tetroxide. The specific preparation method is as follows: (1) Synthesis of BMnMoW-Co(OH)2: First, a 0.2 M cobalt nitrate homogeneous solution was prepared as the electrolyte. Sodium metaborate, potassium permanganate, sodium molybdate and sodium tungstate were added to the cobalt nitrate homogeneous solution and mixed evenly. The concentrations of sodium metaborate, potassium permanganate, sodium molybdate and sodium tungstate in the mixture were all 0.002 M, which is 1% of the molar concentration of cobalt nitrate. That is, the feed ratio of raw materials such as sodium metaborate, potassium permanganate, sodium molybdate and sodium tungstate is 1% of cobalt nitrate.

[0027] The size is 1×2 cm2 Titanium felt was used as the working electrode and carbon rod as the counter electrode for electrodeposition. The experimental conditions for electrodeposition were -1.0 V and 1000 s. The sample obtained by electrodeposition on the titanium felt was denoted as BMnMoW-Co(OH)2.

[0028] (2) Synthesis of BMnMoW-Co3O4: The BMnMoW-Co(OH)2 obtained in step (1) was washed with ultrapure water and ethanol respectively and then transferred to a ceramic boat. The temperature was raised to 350°C at a heating rate of 5°C / min in a tube furnace under nitrogen atmosphere. The material was calcined at this temperature for 200 min. The resulting material is a high-entropy PEM anode catalyst, abbreviated as BMnMoW-Co3O4. Comparative Examples 1-5

[0029] Comparative Examples 1 to 5 follow the same preparation method as the high-entropy PEM anode catalyst in Example 1, differing only in the doping elements.

[0030] Comparative Example 1 used B as the dopant element. Sodium metaborate was added only to the cobalt nitrate solution, and the concentration of sodium metaborate in the mixed solution was 0.008 M. Following the catalyst preparation method of Example 1, the resulting material was designated B-Co3O4. The specific synthesis steps are as follows: (1) Synthesis of B-Co(OH)₂: First, a 0.2 M cobalt nitrate homogeneous solution was prepared as the electrolyte. Sodium metaborate was added to the cobalt nitrate solution, and the concentration of sodium metaborate in the mixture was 0.008 M. A sample with a size of 1×2 cm was then prepared. 2 Titanium felt was used as the working electrode and carbon rod as the counter electrode for electrodeposition. The experimental conditions for electrodeposition were -1.0 V and 1000 s. The resulting sample was denoted as B-Co(OH)2.

[0031] (2) Synthesis of B-Co3O4: The B-Co(OH)2 obtained in step (1) was washed with ultrapure water and ethanol respectively and then transferred to a ceramic boat. The temperature was raised to 350°C in a tube furnace under nitrogen atmosphere at a heating rate of 5°C / min and calcined at this temperature for 200 min. The resulting material was denoted as B-Co3O4.

[0032] The doping elements of Comparative Examples 2, 3, and 4 are Mn, Mo, and W, respectively. Following the method for preparing B-Co3O4 in Comparative Example 1, 0.008M sodium metaborate was replaced sequentially with 0.008M potassium permanganate, sodium molybdate, and sodium tungstate to obtain materials for Comparative Examples 2, 3, and 4, which are denoted as Mn-Co3O4, Mo-Co3O4, and W-Co3O4, respectively.

[0033] Comparative Example 5 was prepared without any other elements, using the same preparation method as in Example 1. The material obtained by electrodeposition and calcination was denoted as Co3O4 and was used as Comparative Example 5, with 0.2M cobalt nitrate homogeneous solution as the electrolyte.

[0034] The XRD patterns of BMnMoW-Co3O4 prepared in Example 1 and Co3O4 prepared in Comparative Example 5 are shown below. Figure 1 As shown, excluding the peaks of the titanium felt substrate, both exhibit only the Co3O4 phase, reflecting the consistency of the material matrix. B, Mn, Mo, and W are all incorporated into the BMnMoW-Co3O4 prepared in Example 1 as dopants. Further ICP-MS elemental analysis of the material prepared in Example 1 yielded the following results: Figure 2 As shown, the content of B in BMnMoW-Co3O4 is 0.24 wt%, the content of Mn is 1.15 wt%, the content of Mo is 1.58 wt%, the content of W is 1.6 wt%, and the content of Co is 95.4 wt%. The above results indicate that B, Mn, Mo, and W-doped high-entropy Co3O4 materials were successfully synthesized in situ on titanium felt in Example 1. Example 2

[0035] The purpose of this embodiment is to analyze the influence of the feeding ratio of each element relative to cobalt nitrate on the product performance.

[0036] Referring to the preparation method in Example 1 where the feed ratio of each raw material in B, Mn, Mo, and W is 1% cobalt nitrate, the concentrations of sodium metaborate, potassium permanganate, sodium molybdate, and sodium tungstate in the electrolyte were adjusted to 0.001 M and 0.004 M, respectively, to obtain BMnMoW-Co3O4 with feed ratios of 0.5% and 2%, which were respectively denoted as BMnMoW(0.5%)-Co3O4 and BMnMoW(2%)-Co3O4.

[0037] Experimental Method: A standard three-electrode test system was constructed using the materials from the above-described examples or comparative examples as the working electrode, a calomel electrode as the reference electrode, and a platinum sheet as the counter electrode. Linear sweep voltammetry was performed on the examples within a voltage range of 1.23 V to 1.8 V vs. RHE.

[0038] The test results are as follows Figure 3 As shown, this indicates that when the feed ratio is 1%, BMnMoW(1%)-Co3O4 at 100 mA cm⁻¹ -2 It exhibits the lowest overpotential of 397 mV at the specified current density, indicating optimal electrocatalytic activity. Example 3

[0039] The purpose of this embodiment is to analyze the effect of different element doping on the product performance.

[0040] Referring to the preparation method in Example 1, 0.002 M of any one of sodium metaborate, potassium permanganate, sodium molybdate, and sodium tungstate was added to a 0.2 M cobalt nitrate homogeneous solution to obtain products B-Co3O4, Mn-Co3O4, Mo-Co3O4, and W-Co3O4, respectively. Referring to the preparation method in Example 1, any three of sodium metaborate (0.002M), potassium permanganate (0.002M), sodium molybdate (0.002M), and sodium tungstate (0.002M) were added to a 0.2 M cobalt nitrate homogeneous solution to obtain products denoted as BMnW-Co3O4, MnMoW-Co3O4, and BMoW-Co3O4.

[0041] Experimental Method: A standard three-electrode test system was constructed using BMnMoW-Co3O4, B-Co3O4, Mn-Co3O4, Mo-Co3O4, W-Co3O4, BMnW-Co3O4, MnMoW-Co3O4, and BMoW-Co3O4 as working electrodes, a calomel electrode as a reference electrode, and a platinum sheet as the counter electrode. Linear sweep voltammetry was performed on the examples within the voltage range of 1.23 V to 1.8 V vs. RHE.

[0042] The polarization curve of this embodiment is as follows: Figure 4 As shown, in a three-electrode system with 0.5 M H₂SO₄ electrolyte, only an overpotential of 253 mV is required to reach 10 mA cm⁻¹. -2 The current density is 10 mA cm⁻¹ at 25°C, while undoped Co₃O₄ requires an overpotential of 367 mV to reach 10 mA cm⁻¹. -2 (25℃) Current density.

[0043] Polarization curves of the BMnMoW-Co3O4 catalyst prepared in Example 1 and the three-element doped Co3O4 are compared. Figure 5 As shown, BMnMoW-Co3O4 at 100 mA cm⁻¹ -2 The material exhibits the lowest overpotential of 397 mV at the specified current density, reflecting its superior performance. This indicates that the high-entropy material BMnMoW-Co3O4 prepared in this invention has superior catalytic activity compared to non-high-entropy materials.

[0044] The performance of BMnMoW-Co3O4 prepared in Example 1 was compared with that of existing IrO2. Figure 6 As shown, BMnMoW-Co3O4 at 100 mA cm⁻¹ -2 The material exhibits the lowest overpotential of 397 mV at the given current density, reflecting its superior performance. This indicates that the high-entropy material BMnMoW-Co3O4 prepared in this invention has superior catalytic activity compared to the noble metal material IrO2.

[0045] The double-layer capacitance of the BMnMoW-Co3O4 catalyst prepared in Example 1 and the comparative example Co3O4 is as follows: Figure 7 As shown, the double-layer capacitance of the high-entropy material in Example 1 is 22.9 mF cm⁻¹. -2 It is Co3O4 (10.3 mF cm⁻¹) -2 The activation energy is twice that of the high-entropy material prepared in this invention, indicating that the high-entropy material has a higher electrochemical active area and conductivity. The activation energies of the BMnMoW-Co3O4 catalyst prepared in Example 1 and the Co3O4 catalyst in Comparative Example 5 are as follows: Figure 8 As shown, the high-entropy material of Example 1 has the lowest activation energy of 1.56 kJ / mol. -1 Compared to Co3O4 (5.17 kJ mol) -1 The energy barrier that needs to be overcome when the reaction occurs is the lowest.

[0046] To further analyze the kinetic characteristics of the electrode reaction, the in-situ impedance test results of the BMnMoW-Co3O4 catalyst prepared in Example 1 and the Co3O4 catalyst in Comparative Example 5 are shown below. Figure 9 As shown, the charge transfer resistance Rct of the high-entropy material in Example 1 is much smaller than that of Co3O4, and the rate at which Rct decreases with potential is much greater than that of Co3O4. This indicates that the electronic conductivity of BMnMoW-Co3O4 prepared in this invention is higher than that of Co3O4. This demonstrates that B, Mn, Mo, and W doping can accelerate the proton transport rate and significantly improve the kinetic activity of Co3O4 material during the electrochemical oxygen reduction reaction.

[0047] The stability tests of the BMnMoW-Co3O4 catalyst prepared in Example 1 and the Co3O4 catalyst in Comparative Example 5 are as follows: Figure 10 As shown, the high-entropy material in Example 1 exhibits excellent stability during actual catalysis. Co3O4 and BMnMoW-Co3O4 were subjected to a 10 mA cm⁻¹ catalysis. -2 (25 ℃) Constant current stability operation was performed. BMnMoW-Co3O4 could operate at constant current for more than 180 h, while Co3O4 was deactivated after 60 h under the same conditions. This shows that multi-metal doping can also effectively improve the stability of Co3O4 under acidic conditions.

[0048] Most current acidic OER catalysts remain at the laboratory three-electrode stage, while the BMnMoW-Co3O4 catalyst prepared in this invention exhibits excellent acidic OER activity and stability in a three-electrode system. The performance of the BMnMoW-Co3O4 catalyst prepared in Example 1 and Comparative Example 5 Co3O4 in a PEM electrolyzer is as follows: Figure 11As shown, its potential in practical water electrolysis (PEMWE) was evaluated. 40% Pt / C was used as the cathode catalyst, BMnMoW-Co3O4 as the oxygen evolution anode catalyst, and Nafion 117 as the proton transport membrane. Its PEM performance was measured at 80 °C. The polarization curves show that the BMnMoW-Co3O4 electrolyzer performs well at 1 A cm⁻¹. -2 The current density requires only a 2.25V tank voltage.

[0049] The stability test results of the BMnMoW-Co3O4 catalyst prepared in Example 1 and the Co3O4 catalyst in Comparative Example 5 in a PEM electrolyzer are shown in the figure below. Figure 12 As shown, time-potential measurements were performed using BMnMoW-Co3O4||Pt / C to evaluate the long-term stability of its PEM electrolyzer. The BMnMoW-Co3O4-based electrolyzer was able to achieve a time-potential ratio of 100 mA cm⁻¹. -2 It can operate continuously and stably for at least 560 hours at the specified current density.

[0050] In summary, this invention provides a simple process for water splitting under acidic conditions, suitable for large-scale production, effectively reducing dependence on the precious metal Ir and lowering the preparation cost of the catalyst. It also possesses excellent electrocatalytic oxygen evolution performance and stability, and has the potential for industrial application in green hydrogen.

[0051] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A high-entropy PEM anode catalyst, characterized in that, The high-entropy PEM anode catalyst consists of a titanium felt and a Co3O4 layer doped with B, Mn, Mo, and W elements grown in situ on the titanium felt. The B, Mn, Mo, and W elements are uniformly doped in the Co3O4 at the atomic scale. The Co3O4 layer contains 95–96 wt% Co, 0.2–0.3 wt% B, 1.1–1.2 wt% Mn, 1.5–1.6 wt% Mo, and 1.6–1.7 wt% W.

2. A method for preparing the high-entropy PEM anode catalyst of claim 1, characterized in that, Includes the following steps: S1: Borate, manganese salt, molybdate and tungstate are added to a homogeneous cobalt nitrate solution to form a mixture, wherein the concentration of cobalt nitrate in the mixture is 0.19–0.21 M; the concentrations of borate, manganese salt, molybdate and tungstate in the mixture are all 0.0019–0.0021 M. S2: Using the mixture prepared in S1 as the electrolyte, titanium felt as the working electrode, and carbon rod as the counter electrode, electrodeposition is performed. The resulting precipitate is denoted as BMnMoW-Co(OH)2. S3: The high-entropy PEM anode catalyst is obtained by washing the BMnMoW-Co(OH)2 prepared in step S2 and calcining it in an inert atmosphere.

3. The method for preparing high-entropy PEM anode catalyst according to claim 2, characterized in that, The molar concentrations of borates, manganese salts, molybdates, and tungstates in the mixture are all 0.5% to 2% of cobalt nitrate.

4. The method for preparing high-entropy PEM anode catalyst according to claim 2, characterized in that, The borate is at least one of sodium metaborate and sodium borate; the manganese salt is at least one of potassium permanganate and potassium manganate; the molybdate is at least one of sodium molybdate, potassium molybdate, and ammonium tetramolybdate; and the tungstate is at least one of sodium tungstate, sodium metatungstate, and potassium tungstate.

5. The method for preparing high-entropy PEM anode catalyst according to claim 2, characterized in that, The electrodeposition potential is -0.9 to -1.1 V, and the deposition time is 900 to 1100 s.

6. The method for preparing high-entropy PEM anode catalyst according to claim 2, characterized in that, The washing described in step S3 includes rinsing BMnMoW-Co(OH)2 sequentially with ultrapure water and anhydrous ethanol.

7. The method for preparing high-entropy PEM anode catalyst according to claim 2, characterized in that, The calcination heating rate is 4–6 °C / min, the calcination temperature is 330–370 °C, and the calcination time is 180–220 min.

8. The method for preparing high-entropy PEM anode catalyst according to claim 2, characterized in that, The inert atmosphere is a nitrogen atmosphere.

9. The application of the high-entropy PEM anode catalyst according to claim 1 in the oxygen evolution reaction of water electrolysis.

10. The application according to claim 9, characterized in that, Using a high-entropy PEM anode catalyst as the working electrode, a calomel electrode as the reference electrode, and a platinum sheet as the counter electrode, a three-electrode testing system was developed. In a 0.5 M H₂SO₄ electrolyte, an overpotential of 10 mA cm⁻¹ was achieved at no more than 253 mV. -2 The current density at 25°C; the activation energy of the high-entropy PEM anode catalyst is not higher than 1.56 kJ mol. -1 ; The high-entropy PEM anode catalyst in the PEM electrolyzer operates at 100 mA cm⁻¹. -2 It can operate continuously and stably for at least 560 hours at the specified current density.

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