Preparation and application of a high-performance, low-precious-metal electrode for water electrolysis
By loading a bimetallic nickel-iron oxide-doped ruthenium catalyst onto a copper foam substrate, the problem of high cost of precious metals in water electrolysis OER was solved, realizing a low-cost and efficient water electrolysis oxygen evolution reaction, which is suitable for large-scale applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-06
- Publication Date
- 2026-04-03
AI Technical Summary
Existing catalysts for the oxygen evolution reaction (OER) in water electrolysis suffer from problems such as high cost of precious metals, low reserves, and insufficient catalytic activity and stability, making it difficult to achieve large-scale industrial application.
Using copper foam as a substrate, a core-shell structured low-noble metal electrode was prepared by loading a bimetallic nickel-iron oxide-doped ruthenium catalyst through hydrothermal heating, high-temperature calcination, and electrodeposition, thereby improving catalytic activity and stability.
It achieves a low-cost, high-efficiency oxygen evolution reaction in water electrolysis, exhibits excellent catalytic activity, is suitable for large-scale production, reduces the amount of precious metals used, and improves the efficiency of hydrogen production through water electrolysis.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of electrocatalytic materials technology, and in particular to the preparation and application of a high-performance, low-precious-metal electrode for water electrolysis. Background Technology
[0002] With the current scarcity of fossil fuel reserves and the increasing severity of environmental pollution, scientists are focusing their efforts on the energy sector, seeking a sustainable and pollution-free clean energy source. Hydrogen energy, as an efficient, clean, and renewable energy carrier, has attracted widespread attention. Among numerous hydrogen production processes, water electrolysis stands out due to its green and environmentally friendly advantages and its independence from fossil fuels. The water electrolysis process involves two half-reactions: the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). However, both HER and OER have relatively low efficiencies. Compared to HER, OER requires four electron transfers and involves more intermediate products, necessitating a higher kinetic barrier, which has become the main bottleneck for OER. Currently, OER catalysts for water electrolysis fall into two categories: noble metal catalysts and non-noble metal catalysts. Noble metal catalysts, such as iridium dioxide (IrO2) and ruthenium dioxide (RuO2), possess high catalytic activity and low overpotentials; however, their high cost and low reserves hinder large-scale industrial applications. While non-noble metal catalysts reduce costs, their catalytic activity and stability are far lower than those of noble metal catalysts.
[0003] To address the aforementioned problems, this invention provides a method for loading a bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst onto the surface of copper foam as a substrate using hydrothermal heating, high-temperature calcination, and electrodeposition methods. This method offers a catalyst with low specific surface area, high specific activity, low cost, and simple preparation method, characterized by the doping of a small amount of noble metal. Summary of the Invention
[0004] The purpose of this invention is to provide a high-performance, low-precious-metal electrode for water electrolysis and its application, so as to solve the problems mentioned in the background art.
[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a high-performance, low-precious-metal electrode for water electrolysis, comprising the following steps:
[0006] S1: Place the foamed copper in ultrapure water and hydrochloric acid for ultrasonic cleaning for 30 min, then clean it with water, ethanol or acetone, and vacuum dry it at 50℃-80℃ for 2-12 h.
[0007] S2: Mix copper salt with stabilizer and stir magnetically for 20-60 min to form a precursor copper salt solution. At room temperature, electrodeposit a layer of metallic Cu on the surface of the foamed copper substrate under constant voltage. After cleaning and drying, place the treated foamed copper in a muffle furnace and react at 150-400℃ for 2-5 h. Then cool to room temperature to obtain CuO-Cu. The preferred temperature is 200-300℃ and the reaction time is 2-3 h.
[0008] S3: Dissolve the precursor nickel salt, precursor M salt and alkaline precipitant in ultrapure water, stir and then put the treated foamed copper into the water for hydrothermal reaction. After separation and drying, precursor a is obtained.
[0009] S4: Precursor a is calcined in air at 200℃-600℃ to obtain precursor CuO-Cu@Ni. x M y O z ;
[0010] S5: Using ruthenium chloride solution as the electrolyte, under room temperature conditions, the precursor CuO-Cu@Ni... x M y O z Using CuO-Cu@Ni as a carrier under constant voltage conditions x M y O z Ru was electrodeposited on the surface to prepare CuO-Cu@Ni with a core-shell structure. x M y O z @Ru catalyst for water electrolysis using low-precious metal electrodes.
[0011] Preferably, the stabilizer in S2 is polyvinylpyrrolidone (PVP) or Triton X-100 (C 14 H 22 O(C2H4O) n One or two of the following are used, with a concentration of 0.01M-0.18M, preferably 0.05M-0.15M.
[0012] Preferably, the precursor nickel salt in S3 is one of Ni(NO3)2·6H2O, NiCl2·6H2O, and NiSO4·6H2O, wherein the concentration of nickel ions is 0.1mM to 1.0M, preferably 0.05M to 0.5M. The precursor M salt is one of Fe(NO3)3·9H2O, FeCl3·6H2O, and Fe2(SO4)3·H2O, wherein the concentration of iron ions is 0.2mM to 2.0M, preferably 0.08M to 0.3M.
[0013] Preferably, the alkaline precipitant in S3 is one or more of urea, ammonia, sodium bicarbonate, sodium carbonate, and ammonium bicarbonate, and the concentration of the alkaline precipitant is 1 mmol / L to 1.0 mol / L, wherein the molar ratio of the alkaline precipitant to nickel in the precursor nickel salt solution is 0.5:1 to 50:1, and the molar ratio of the alkaline precipitant to iron in the precursor M salt solution is 1:2 to 50:1.
[0014] Preferably, the hydrothermal reaction in S3 is carried out at a temperature of 110℃-200℃ for 4h-14h.
[0015] Preferably, in step S4, the precursor a is placed in a muffle furnace for calcination. The calcination process conditions are as follows: the heating rate is controlled at 2℃ / min, and the temperature is raised to 200℃-600℃ for calcination for 2 hours.
[0016] Preferably, the concentration of the ruthenium chloride solution in S5 is 1 mmol / L to 1.0 mol / L, the constant voltage is 0.07V (vs. SHE), the deposition time is 300-800s, and then deposition is performed at 0.05V vs. SHE for 300-800s.
[0017] Preferably, M is one or more of the transition metals Fe, Co, W, and Mo, wherein the Ru content is 2wt%-40wt%, the Ni content is 15wt%-20wt%, the Fe content is 30wt%-45wt%, and the O content is 15wt%-33wt%.
[0018] The present invention also discloses a high-performance, low-precious metal electrode for water electrolysis, which is prepared by a method for preparing a high-performance, low-precious metal electrode for water electrolysis.
[0019] The present invention also discloses the application of a high-performance, low-precious-metal electrode for water electrolysis, wherein the high-performance, low-precious-metal electrode for water electrolysis is used in the electrocatalytic alkaline oxygen evolution reaction.
[0020] The technical effects and advantages of this invention are as follows:
[0021] 1. According to the above embodiments, a high-performance, low-precious metal electrode for water electrolysis is provided, namely: a bimetallic nickel-iron oxide doped ruthenium oxygen evolution reaction catalyst. The preparation method of this catalyst uses copper foam as a carrier and nickel-iron as a metal source. First, a precursor is prepared by electrodeposition, hydrothermal method and high-temperature annealing method. Then, the core-shell structured bimetallic nickel-iron oxide doped ruthenium oxygen evolution reaction catalyst is prepared by electrodeposition of the precursor.
[0022] 2. The bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst of the present invention firstly uses copper foam as a support, and performs electrodeposition and air calcination on the support to form CuO nanoparticles on the surface of the copper foam, which can enhance the conductivity of the entire system and the stability of the catalyst material itself, and facilitate the transport of a large number of electrons and expose more active sites. In addition, the use of nickel-iron as a metal source can better improve the catalytic activity of the entire system. Furthermore, the doping of the noble metal ruthenium can further improve the stability and catalytic activity of the catalyst. Since the preparation process adopts a hydrothermal, high-temperature annealing-electrodeposition method, the entire synthesis process is simple, the raw materials are inexpensive and widely available, and large-scale production is possible.
[0023] 3. Tests show that the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst exhibits excellent catalytic activity (at a current density of 50 mA cm⁻¹). -2 The overpotential is only 377mV, indicating that the bimetallic nickel-iron oxide-doped ruthenium catalyst exhibits good electrocatalytic activity for the oxygen evolution reaction under alkaline conditions. Compared with existing technologies, the raw materials of this invention are widely available and inexpensive, and the preparation process is simple and straightforward, which is beneficial for improving the efficiency of hydrogen production through water electrolysis and promoting the widespread use of hydrogen energy.
[0024] 4. The hydrothermal reaction duration and temperature parameters during the preparation of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst of this invention ensure that the prepared precursor has a stable structure and good crystallinity. The calcination temperature and duration parameters during the high-temperature annealing process ensure complete oxidation of the precursor, and the doping of the noble metal ruthenium makes the final product structurally stable, with high catalytic activity and good conductivity. Therefore, this invention exhibits excellent performance and good stability during performance testing. Attached Figure Description
[0025] Figure 1 The linear sweep voltammetry of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst obtained in Example 1 in 1M KOH solution;
[0026] Figure 2 Linear voltammetric curves of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst obtained in Example 1 at different reaction temperatures in 1M KOH solution during hydrothermal reaction, with the same reaction time.
[0027] Figure 3 Linear voltammetric curves of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst obtained in Example 1 in 1M KOH solution, at the same reaction temperature and different reaction times in a hydrothermal reaction.
[0028] Figure 4Linear voltammetric curves of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst obtained in Example 1 in 1M KOH solution at different high-temperature annealing temperatures.
[0029] Figure 5 The time-voltage curve of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst obtained in Example 1 in 1M KOH solution;
[0030] Figure 6 The image shows the SEM image of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst obtained in Example 1. Detailed Implementation
[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0032] Example 1
[0033] This invention provides, for example Figures 1-6 The method for preparing a high-performance, low-precious-metal electrode for water electrolysis includes the following steps:
[0034] S1: Place the foamed copper in ultrapure water and hydrochloric acid for ultrasonic cleaning for 30 min, then clean it with water, ethanol or acetone, and vacuum dry it at 50℃-80℃ for 2-12 h.
[0035] S2: Mix copper salt with stabilizer and stir magnetically for 20-60 min to form a precursor copper salt solution. At room temperature, electrodeposit a layer of metallic Cu on the surface of the foamed copper substrate under constant voltage. After cleaning and drying, place the treated foamed copper in a muffle furnace and react at 150-400℃ for 2-5 h. Then cool to room temperature to obtain CuO-Cu. The preferred temperature is 200-300℃ and the reaction time is 2-3 h.
[0036] S3: Dissolve the precursor nickel salt, precursor M salt and alkaline precipitant in ultrapure water, stir and then put the treated foamed copper into the water for hydrothermal reaction. After separation and drying, precursor a is obtained.
[0037] S4: Precursor a is calcined in air at 200℃-600℃ to obtain precursor CuO-Cu@Ni. x M y O z ;
[0038] S5: Using ruthenium chloride solution as the electrolyte, under room temperature conditions, the precursor CuO-Cu@Ni... x M y O z Using CuO-Cu@Ni as a carrier under constant voltage conditions x M y O z Ru was electrodeposited on the surface to prepare CuO-Cu@Ni with a core-shell structure. x M y O z @Ru catalyst for water electrolysis using low-precious metal electrodes.
[0039] The stabilizers in S2 are polyvinylpyrrolidone (PVP) and Triton X-100 (C). 14 H 22 O(C2H4O) n One or two of the following are used, with a concentration of 0.01M-0.18M, preferably 0.05M-0.15M.
[0040] The precursor nickel salt in S3 is one of Ni(NO3)2·6H2O, NiCl2·6H2O, and NiSO4·6H2O, wherein the concentration of nickel ions is 0.1mM to 1.0M, preferably 0.05M to 0.5M. The precursor M salt is one of Fe(NO3)3·9H2O, FeCl3·6H2O, and Fe2(SO4)3·H2O, wherein the concentration of iron ions is 0.2mM to 2.0M, preferably 0.08M to 0.3M.
[0041] The alkaline precipitant in S3 is one or more of urea, ammonia, sodium bicarbonate, sodium carbonate, and ammonium bicarbonate. The concentration of the alkaline precipitant is 1 mmol / L to 1.0 mol / L. The molar ratio of the alkaline precipitant to nickel in the precursor nickel salt solution is 0.5:1 to 50:1, and the molar ratio of the alkaline precipitant to iron in the precursor M salt solution is 1:2 to 50:1.
[0042] The hydrothermal reaction in S3 takes place at a temperature of 110℃-200℃ for 4h-14h.
[0043] In S4, precursor a is placed in a muffle furnace for calcination. The calcination process conditions are as follows: the heating rate is controlled at 2℃ / min, and the temperature is raised to 200℃-600℃ for calcination for 2 hours.
[0044] The concentration of ruthenium chloride solution in S5 is 1 mmol / L to 1.0 mol / L. The constant voltage is 0.07V (vs. SHE), the deposition time is 300-800s, and then deposition is performed at 0.05V vs. SHE for 300-800s.
[0045] M is one or more of the transition metals Fe, Co, W and Mo, wherein the content of Ru is 2wt%-40wt%, the content of Ni is 15wt%-20wt%, the content of Fe is 30wt%-45wt%, and the content of O is 15wt%-33wt%.
[0046] The present invention also discloses a high-performance, low-precious metal electrode for water electrolysis, which is prepared by a method for preparing a high-performance, low-precious metal electrode for water electrolysis.
[0047] This invention also discloses the application of a high-performance, low-precious-metal electrode for water electrolysis, which is used in the electrocatalytic alkaline oxygen evolution reaction.
[0048] 1. Cut a certain amount of foamed copper and press it into tablets. Then, clean it in ultrapure water and hydrochloric acid and sonicate it for 30 minutes. Then, clean it with water, ethanol or acetone and vacuum dry it at 60°C for 6 hours.
[0049] 2. Mix 55 mL of 0.2 M CuCl2·2H2O solution with 165 mL of 0.06 M PVP solution as the electrolyte. Electrodeposit for 1800 s under a constant voltage of -0.3 V (vs. Ag / AgCl) to obtain a layer of metallic Cu. After cleaning and drying, place the treated copper foam in a muffle furnace and react at 300 °C for 2 h. Then cool to room temperature to obtain CuO-Cu.
[0050] 3. Ni(NO3)2·6H2O was selected as the precursor nickel salt solution, and Fe(NO3)3·9H2O was selected as the precursor M salt solution, wherein the concentration of nickel ions was 0.05 M and the concentration of iron ions was 0.1 M. A certain amount of urea was added as an alkaline precipitant, so that the molar ratio of alkaline precipitant to nickel ions was 20:1. The mixture was magnetically stirred for 30 min.
[0051] 4. The mixed solution and the treated copper foam were transferred to a hydrothermal reactor and heated in a high-temperature oven at 180°C for 12 hours. Finally, the mixture was cooled to room temperature. The cooled nickel foam was taken out and rinsed with water and anhydrous ethanol. The mixture was then vacuum dried at 60°C for 12 hours to obtain the dried precursor a.
[0052] 5. Precursor a was calcined in air at high temperature, with the heating rate controlled at 2℃ / min, and calcined at 300℃ for 2h to obtain precursor CuO-Cu@NiFe2O4.
[0053] 6. Using 100 mL of 10 mmol / L ruthenium chloride solution as the electrolyte, a deposition time of 300-800 s was achieved at a constant voltage of 0.07 V (vs. SHE), followed by deposition at 0.05 V vs. SHE for 300-800 s. After rinsing, a core-shell structured CuO-Cu@NiFe2O4@Ru catalyst was obtained.
[0054] Figure 1 The corresponding data is a linear sweep voltammetry plot of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst in 1M KOH solution.
[0055] from Figure 1 It can be seen that the overpotential of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst is significantly lower than that of the undoped ruthenium catalyst: the overpotential of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst at a current density of 50 mA cm⁻¹ is significantly lower. -2 The overpotential was 377 mV, which was 66 mV lower than that of nickel-iron oxide at the same current density, thus proving that the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst has higher catalytic activity for the oxygen evolution reaction of water electrolysis.
[0056] Example 2
[0057] Compared with Example 1, except that the hydrothermal reaction temperatures were changed to 110℃, 130℃, 150℃ and 200℃ respectively, the rest of the operation was the same as in Example 1, and its performance was as follows: Figure 2 As shown, its performance is weaker than that of materials with a reaction temperature of 180℃.
[0058] Example 3
[0059] Compared with Example 1, except that the solvothermal reaction time was changed to 4h, 6h, 8h and 14h respectively, the rest of the operation was the same as in Example 1, and its performance was as follows: Figure 3 As shown, its performance is weaker than that of the material with a duration of 12 hours.
[0060] Example 4
[0061] Compared with Example 1, except that the high-temperature annealing temperatures were changed to 200℃, 400℃, 500℃, and 600℃ respectively, the rest of the operation was the same as in Example 1, and its performance was as follows. Figure 4 As shown, its performance is weaker than that of materials annealed at 300℃.
[0062] Comparative Example 1
[0063] 1. Cut a certain amount of foamed copper and press it into tablets. Then, clean it in ultrapure water and hydrochloric acid and sonicate it for 30 minutes. Then, clean it with water, ethanol or acetone and vacuum dry it at 60°C for 6 hours.
[0064] 2. Ni(NO3)2·6H2O was selected as the precursor nickel salt solution, and Fe(NO3)3·9H2O was selected as the precursor M salt solution, wherein the concentration of nickel ions was 0.05 M and the concentration of iron ions was 0.1 M. A certain amount of urea was added as an alkaline precipitant, so that the molar ratio of alkaline precipitant to nickel ions was 20:1. The mixture was magnetically stirred for 30 min.
[0065] 3. The mixed solution and the treated copper foam were transferred to a hydrothermal reactor and heated in a high-temperature oven at 180°C for 12 hours. Finally, the mixture was cooled to room temperature. The cooled nickel foam was taken out and rinsed with water and anhydrous ethanol. The mixture was then vacuum dried at 60°C for 12 hours to obtain the dried precursor a.
[0066] 4. Precursor a was calcined in air at high temperature, with the heating rate controlled at 2℃ / min, and calcined at 300℃ for 2h to obtain precursor Cu@NiFe2O4.
[0067] 5. Using 100 mL of 10 mmol / L ruthenium chloride solution as the electrolyte, a deposition time of 300-800 s was achieved at a constant voltage of 0.07 V (vs. SHE), followed by deposition at 0.05 V vs. SHE for 300-800 s. After rinsing, a core-shell structured Cu@NiFe2O4@Ru catalyst was obtained.
[0068] Comparative Example 2
[0069] 1. Cut a certain amount of foamed copper and press it into tablets. Then, clean it in ultrapure water and hydrochloric acid and sonicate it for 30 minutes. Then, clean it with water, ethanol or acetone and vacuum dry it at 60°C for 6 hours.
[0070] 2. 55 mL of 0.2 M CuCl2·2H2O solution was mixed with 165 mL of 0.06 M PVP solution as the electrolyte. Under a constant voltage of -0.3 V (vs. Ag / AgCl), electrodeposition was performed for 1800 s to obtain a layer of metallic Cu. After cleaning and drying, the treated copper foam was placed in a muffle furnace and reacted at 300 °C for 2 h. Then, it was cooled to room temperature to obtain CuO-Cu.
[0071] 3. Ni(NO3)2·6H2O was selected as the precursor nickel salt solution, and Fe(NO3)3·9H2O was selected as the precursor M salt solution, wherein the concentration of nickel ions was 0.05 M and the concentration of iron ions was 0.1 M. A certain amount of urea was added as an alkaline precipitant, so that the molar ratio of alkaline precipitant to nickel ions was 20:1. The mixture was magnetically stirred for 30 min.
[0072] 4. The mixed solution and the treated copper foam were transferred to a hydrothermal reactor and heated in a high-temperature oven at 180°C for 12 hours. Finally, the mixture was cooled to room temperature. The cooled nickel foam was taken out and rinsed with water and anhydrous ethanol. The mixture was then vacuum dried at 60°C for 12 hours to obtain the dried precursor a.
[0073] 5. Using 100 mL of 10 mmol / L ruthenium chloride solution as the electrolyte, a deposition time of 300-800 s was achieved at a constant voltage of 0.07 V (vs. SHE), followed by deposition at 0.05 V vs. SHE for 300-800 s. After rinsing, a core-shell structured CuO-Cu@NiFeLDH@Ru catalyst was obtained.
[0074] Comparative Example 3
[0075] 1. Cut a certain amount of foamed copper and press it into tablets. Then, clean it in ultrapure water and hydrochloric acid and sonicate it for 30 minutes. Then, clean it with water, ethanol or acetone and vacuum dry it at 60°C for 6 hours.
[0076] 2. Mix 55 mL of 0.2 M CuCl2·2H2O solution with 165 mL of 0.06 M PVP solution as the electrolyte. Electrodeposit for 1800 s under a constant voltage of -0.3 V (vs. Ag / AgCl) to obtain a layer of metallic Cu. After cleaning and drying, place the treated copper foam in a muffle furnace and react at 300 °C for 2 h. Then cool to room temperature to obtain CuO-Cu.
[0077] 3. Co(NO3)3·6H2O was selected as the precursor nickel salt solution, and Fe(NO3)3·9H2O was selected as the precursor M salt solution, wherein the concentration of cobalt ions was 0.05 M and the concentration of iron ions was 0.1 M. A certain amount of urea was added as an alkaline precipitant, so that the molar ratio of alkaline precipitant to cobalt ions was 20:1. The mixture was magnetically stirred for 30 min.
[0078] 4. The mixed solution and the treated copper foam were transferred to a hydrothermal reactor and heated in a high-temperature oven at 180°C for 12 hours. Finally, the mixture was cooled to room temperature. The cooled nickel foam was taken out and rinsed with water and anhydrous ethanol. The mixture was then vacuum dried at 60°C for 12 hours to obtain the dried precursor a.
[0079] 5. Precursor a was calcined in air at a high temperature, with a heating rate of 2℃ / min, and calcined at 300℃ for 2 hours to obtain the precursor CuO-Cu@CoFe. x O y ;
[0080] 6. Using 100 mL of 10 mmol / L ruthenium chloride solution as the electrolyte, deposition was carried out at a constant voltage of 0.07 V (vs. SHE) for 300-800 s, followed by deposition at 0.05 V vs. SHE for 300-800 s. After rinsing, a core-shell structure CuO-Cu@CoFe was obtained. x O y @Ru catalyst.
[0081] Comparative Example 4
[0082] 1. Cut a certain amount of foamed copper and press it into tablets. Then, clean it in ultrapure water and hydrochloric acid and sonicate it for 30 minutes. Then, clean it with water, ethanol or acetone and vacuum dry it at 60°C for 6 hours.
[0083] 2. Mix 55 mL of 0.2 M CuCl2·2H2O solution with 165 mL of 0.06 M PVP solution as the electrolyte. Electrodeposit for 1800 s under a constant voltage of -0.3 V (vs. Ag / AgCl) to obtain a layer of metallic Cu. After cleaning and drying, place the treated copper foam in a muffle furnace and react at 300 °C for 2 h. Then cool to room temperature to obtain CuO-Cu.
[0084] 3. Using 100 mL of 10 mmol / L ruthenium chloride solution as the electrolyte, a deposition time of 300-800 s was achieved at a constant voltage of 0.07 V (vs. SHE), followed by deposition at 0.05 V vs. SHE for 300-800 s. After rinsing, a core-shell structured CuO-Cu@Ru catalyst was obtained.
[0085] Comparative Example 5
[0086] 1. Cut a certain amount of foamed copper and press it into tablets. Then, clean it in ultrapure water and hydrochloric acid and sonicate it for 30 minutes. Then, clean it with water, ethanol or acetone and vacuum dry it at 60°C for 6 hours.
[0087] 2. Mix 55 mL of 0.2 M CuCl2·2H2O solution with 165 mL of 0.06 M PVP solution as the electrolyte. Electrodeposit for 1800 s under a constant voltage of -0.3 V (vs. Ag / AgCl) to obtain a layer of metallic Cu. After cleaning and drying, place the treated copper foam in a muffle furnace and react at 300 °C for 2 h. Then cool to room temperature to obtain CuO-Cu.
[0088] 3. Ni(NO3)2·6H2O was selected as the precursor nickel salt solution, and Fe(NO3)3·9H2O was selected as the precursor M salt solution, wherein the concentration of nickel ions was 0.05 M and the concentration of iron ions was 0.1 M. A certain amount of urea was added as an alkaline precipitant, so that the molar ratio of alkaline precipitant to nickel ions was 20:1. The mixture was magnetically stirred for 30 min.
[0089] 4. The mixed solution and the treated copper foam were transferred to a hydrothermal reactor and heated in a high-temperature oven at 180°C for 12 hours. Finally, the mixture was cooled to room temperature. The cooled nickel foam was taken out and rinsed with water and anhydrous ethanol. The mixture was then vacuum dried at 60°C for 12 hours to obtain the dried precursor a.
[0090] 5. Precursor a was calcined in air at a high temperature, with the heating rate controlled at 2℃ / min, and calcined at 300℃ for 2h to obtain the precursor CuO-Cu@NiFe2O4.
[0091] Figure 2 The corresponding data are linear sweep voltammetry plots of bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalysts in 1M KOH solution at different hydrothermal reaction temperatures.
[0092] from Figure 2 As can be seen, the overpotential of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst at 180℃ is significantly lower than that of the catalysts at other reaction temperatures; the overpotential of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst reaches 50 mA / cm². -2 The overpotential at the current density was 377 mV, which is better than that of the complex obtained at other reaction temperatures, thus proving that the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst has the best catalytic activity for the oxygen evolution reaction of water electrolysis at a reaction temperature of 180 °C.
[0093] Figure 3 The corresponding data are linear sweep voltammetry plots of bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalysts in 1M KOH solution at different hydrothermal reaction times.
[0094] from Figure 3 It can be seen that the overpotential of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst at a reaction time of 12 h is significantly lower than that of the catalysts at other reaction times; the overpotential of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst reaches 50 mA cm⁻¹. -2 The overpotential at the current density was 377 mV, which was better than that of the complex obtained at other reaction times, thus proving that the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst has the best catalytic activity for oxygen evolution in water electrolysis at a reaction time of 12 h.
[0095] Figure 4The corresponding data are linear sweep voltammetry plots of bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalysts in 1M KOH solution at different high-temperature annealing temperatures.
[0096] from Figure 4 As can be seen, the overpotential of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst at a high-temperature annealing temperature of 300℃ is significantly lower than that of catalysts at other annealing temperatures; the overpotential of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst reaches 50 mA cm⁻¹. -2 The overpotential at the current density was 377 mV, which is better than that of catalysts obtained at other annealing temperatures, thus proving that the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst has the best catalytic activity for oxygen evolution in water electrolysis at an annealing temperature of 300 °C.
[0097] Figure 5 The corresponding curve is the time-voltage curve of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst obtained in Example 1 in 1M KOH solution.
[0098] from Figure 5 The results show that the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst exhibits no voltage decay after 25 hours of reaction in 1M KOH solution, indicating its electrocatalytic activity and electrochemical stability under alkaline conditions.
[0099] The SEM images of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst obtained above were obtained using a scanning electron microscope (Quanta 400FEG, manufactured by FEI Corporation, USA), as shown below. Figure 6 As shown. From Figure 6 It can be seen that the obtained bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst has a plate-like structure.
[0100] The function and effect of this invention:
[0101] According to the preparation method of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst provided in the above embodiments, copper foam is selected as the support and nickel-iron is selected as the metal source. The precursor is first prepared by electrodeposition, hydrothermal method and high temperature annealing method. Then, the core-shell structured bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst is prepared by electrodeposition of the precursor.
[0102] The bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst of this invention first uses copper foam as a support. The support is electrodeposited and then calcined in air to form CuO nanoparticles on the surface of the copper foam, which enhances the conductivity of the entire system and the stability of the catalyst material itself, facilitating the transport of a large number of electrons and exposing more active sites. Furthermore, using nickel-iron as the metal source further improves the catalytic activity of the entire system. Additionally, the doping of the noble metal ruthenium further enhances the stability and catalytic activity of the catalyst. Because the preparation process employs a hydrothermal, high-temperature annealing-electrodeposition method, the entire synthesis procedure is simple, and the raw materials are inexpensive and widely available, allowing for large-scale production.
[0103] Tests showed that the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst exhibited excellent catalytic activity (at a current density of 50 mA cm⁻¹). -2 The overpotential is only 377mV, indicating that the bimetallic nickel-iron oxide-doped ruthenium catalyst exhibits good electrocatalytic activity for the oxygen evolution reaction under alkaline conditions. Compared with existing technologies, the raw materials of this invention are widely available and inexpensive, and the preparation process is simple and straightforward, which is beneficial for improving the efficiency of hydrogen production through water electrolysis and promoting the widespread use of hydrogen energy.
[0104] The hydrothermal reaction duration and temperature parameters during the preparation of the bimetallic nickel-iron oxide-doped ruthenium oxygen evolution reaction catalyst of this invention ensure that the prepared precursor has a stable structure and good crystallinity. The calcination temperature and duration parameters during the high-temperature annealing process ensure complete oxidation of the precursor, and the doping of the noble metal ruthenium contributes to the structural stability of the final product, resulting in high catalytic activity and good conductivity. Therefore, this invention exhibits excellent performance and good stability during performance testing.
Claims
1. A method for preparing a high-performance, low-precious-metal electrode for water electrolysis, characterized in that: Includes the following steps: S1: Place the foamed copper in ultrapure water and hydrochloric acid for ultrasonic cleaning for 30 min, then clean it with water, ethanol or acetone, and vacuum dry it at 50℃-80℃ for 2-12 h. S2: Mix copper salt with stabilizer and stir magnetically for 20-60 min to form a precursor copper salt solution. At room temperature, electrodeposit a layer of metallic Cu on the surface of the foamed copper substrate under constant voltage. After cleaning and drying, place the treated foamed copper in a muffle furnace and react at 150-400℃ for 2-5 h. Then cool to room temperature to obtain CuO-Cu. S3: Dissolve the precursor nickel salt, precursor M salt and alkaline precipitant in ultrapure water, stir and then put the treated foamed copper into the water for hydrothermal reaction. After separation and drying, precursor a is obtained. S4: Precursor a is calcined in air at 200℃-600℃ to obtain precursor CuO-Cu@Ni. x M y O z ; S5: Using ruthenium chloride solution as the electrolyte, under room temperature conditions, the precursor CuO-Cu@Ni... x M y O z Using CuO-Cu@Ni as a carrier under constant voltage conditions x M y O z Ru was electrodeposited on the surface to prepare CuO-Cu@Ni with a core-shell structure. x M y O z @Ru catalyst for water electrolysis using low-precious metal electrodes.
2. The method for preparing a high-performance, low-precious-metal electrode for water electrolysis according to claim 1, characterized in that: The stabilizer in S2 is polyvinylpyrrolidone (PVP) and Triton X-100 (C). 14 H 22 O(C2H4O) n One or two of them, with a concentration of 0.01M-0.18M.
3. The method for preparing a high-performance, low-precious-metal electrode for water electrolysis according to claim 2, characterized in that: The precursor nickel salt in S3 is one of Ni(NO3)2·6H2O, NiCl2·6H2O, and NiSO4·6H2O, wherein the concentration of nickel ions is 0.1mM to 1.0M. The precursor M salt is one of Fe(NO3)3·9H2O, FeCl3·6H2O, and Fe2(SO4)3·H2O, wherein the concentration of iron ions is 0.2mM to 2.0M.
4. The method for preparing a high-performance, low-precious-metal electrode for water electrolysis according to claim 3, characterized in that: The alkaline precipitant in S3 is one or more of urea, ammonia, sodium bicarbonate, sodium carbonate, and ammonium bicarbonate. The concentration of the alkaline precipitant is 1 mmol / L to 1.0 mol / L. The molar ratio of the alkaline precipitant to nickel in the precursor nickel salt solution is 0.5:1 to 50:1, and the molar ratio of the alkaline precipitant to iron in the precursor M salt solution is 1:2 to 50:
1.
5. The method for preparing a high-performance, low-precious-metal electrode for water electrolysis according to claim 4, characterized in that: The hydrothermal reaction in S3 is carried out at a temperature of 110℃-200℃ for a duration of 4h-14h.
6. The method for preparing a high-performance, low-precious-metal electrode for water electrolysis according to claim 5, characterized in that: In S4, the precursor a is placed in a muffle furnace for calcination. The calcination process conditions are as follows: the heating rate is controlled at 2℃ / min, and the temperature is raised to 200℃-600℃ for calcination for 2 hours.
7. The method for preparing a high-performance, low-precious-metal electrode for water electrolysis according to claim 6, characterized in that: The concentration of the ruthenium chloride solution in S5 is 1 mmol / L to 1.0 mol / L, the constant voltage is 0.07V or 0.05V, and the deposition time is 300-800s.
8. The method for preparing a high-performance, low-precious-metal electrode for water electrolysis according to claim 7, characterized in that: M is one or more of the transition metals Fe, Co, W and Mo, wherein the content of Ru is 2wt%-40wt%, the content of Ni is 15wt%-20wt%, the content of Fe is 30wt%-45wt%, and the content of O is 15wt%-33wt%.
9. A high-performance, low-precious-metal electrode for water electrolysis, characterized in that, It is prepared by any one of the methods for preparing a high-performance, low-precious metal electrode for water electrolysis according to claims 1-8.
10. The application of the high-performance, low-precious-metal electrode for water electrolysis according to claim 9, characterized in that: The high-performance, low-precious-metal electrode for water electrolysis is used in the electrocatalytic alkaline oxygen evolution reaction.