Method for preparing nickel-based modified catalyst through stepped electrochemical activation
The nickel mesh substrate is modified by step electrochemical activation method to prepare a high-performance nickel-based modified catalyst, which solves the problems of insufficient and unstable catalytic performance of existing nickel-based catalysts, and achieves the effect of improving catalytic activity and high process economics.
Patent Information
- Application Number
- CN202510164964.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-14
- Publication Date
- 2025-05-13
AI Technical Summary
The existing nickel-based catalysts have insufficient catalytic performance in electrolytic water hydrogen production system, and the utilization rate of additional catalysts is low and the catalyst layer is unstable in high concentration alkali liquid.
The nickel mesh substrate was modified by step electrochemical activation method, and a high-performance nickel-based modification catalyst was prepared by soaking in a salt solution at a constant temperature, applying step potentials in an alkaline electrolyte solution, and impregnating in a cobalt nitrate solution.
The catalytic activity and structural stability of nickel-based catalysts are improved, and the problem of low utilization and instability of additional metal sources is reduced. The process economy is high and production is easy to expand.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of water electrolysis catalysts, and in particular to a method for preparing a nickel-based modified catalyst by step-by-step electrochemical activation. Background Art
[0002] As an important chemical raw material and energy carrier, the demand for hydrogen is growing. Among the many hydrogen production technologies, water electrolysis is considered to be one of the most promising hydrogen production technologies. Since catalysts play a decisive role in water electrolysis hydrogen production systems, improving the catalytic performance and structural stability of catalytic materials through different methods is the focus of current research in this field. Among them, nickel-based catalysts have been widely used due to their advantages such as corrosion resistance, excellent stability and high raw material reserves, but their catalytic performance still has a lot of room for improvement, and there are problems such as low catalyst raw material utilization and instability of the catalyst layer in high-concentration alkaline solutions.
[0003] At present, the nickel mesh substrate used in the actual water electrolysis hydrogen production system mostly needs to be additionally loaded with high-performance catalysts through thermal spraying, plasma spraying and other methods. Many related studies focus on the methods of loading catalysts and the types of loaded catalysts. However, without adding additional catalysts, the nickel mesh substrate is activated to increase the active sites on its surface, so as to effectively reduce the cost of electrode catalysts and avoid the catalyst coating from falling off in a strong alkaline environment, causing unstable performance problems, thereby promoting the sustainable development of water electrolysis hydrogen production technology. Summary of the invention
[0004] In view of some shortcomings of the current water electrolysis technology, the main purpose of the present invention is to provide a method for preparing a nickel-based modified catalyst by step-by-step electrochemical activation. The prepared nickel-based catalyst has strong practicability, simple process, high economy, and is easy to expand process production, and avoids the problems of low utilization and instability of additional added metal sources.
[0005] In order to solve the above technical problems, a technical solution adopted by the present invention is: a method for preparing a nickel-based modified catalyst by step-by-step electrochemical activation, the steps of which include: (1) Soaking the sandblasted nickel mesh substrate in a salt solution of a certain concentration at a certain constant temperature to corrode the surface of the nickel mesh substrate and increase the sites on the nickel mesh surface that can be electrochemically activated; (2) Using a double-electrode system in an alkaline electrolyte of a certain concentration to perform step potential activation on the pretreated nickel mesh; (3) After activation, the catalyst is thoroughly washed with deionized water, soaked in a cobalt nitrate solution, and finally washed to obtain a high-performance nickel-based catalyst.
[0006] In an embodiment of the present invention, in step (1), the salt solution is KCl solution.
[0007] In an embodiment of the present invention, in step (1), the nickel mesh pretreatment temperature is 20-150° C., the KCl solution concentration is 0.1-5 M, and the immersion time is 1-24 h.
[0008] In an embodiment of the present invention, the sandblasted nickel mesh substrate is a single-sided sandblasted nickel mesh or a double-sided sandblasted nickel mesh.
[0009] In an embodiment of the present invention, in step (2), the concentration of the alkaline electrolyte is 0.1M~10M KOH.
[0010] In an embodiment of the present invention, in step (2), the activation potential applied is 1-6 V, the potential increasing gradient is 0.1-1 V, and the single potential activation time is 1-60 min.
[0011] In an embodiment of the present invention, in step (3), the concentration of the cobalt nitrate solution is 0.01-2 M, and the immersion time is 1-120 min.
[0012] The beneficial effects of the present invention are as follows: the nickel-based modified catalyst prepared by the present invention uses a nickel mesh substrate as a nickel source, increases the active sites on the surface of the nickel mesh by applying a step potential activation, and subsequently performs cobalt nitrate impregnation to stabilize the activation state of the nickel mesh surface and further enhance its catalytic activity, has high economic efficiency, is easy to expand process production, and avoids the problems of low utilization and instability of additional added metal sources. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which: Figure 1 Schematic diagram of electrochemical activation potential application in Example 1 of the present invention; Figure 2 is the oxygen evolution performance curve of the nickel-based catalyst prepared in Example 1 of the present invention; Figure 3 This is a stability test chart of the nickel-based catalyst prepared in Example 2. DETAILED DESCRIPTION
[0014] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0015] See also Figure 1-3 , the embodiment of the present invention includes: a method for preparing a nickel-based modified catalyst by step-by-step electrochemical activation, comprising the following steps: (1) Soaking the sandblasted nickel mesh substrate in a salt solution of a certain concentration at a certain constant temperature to corrode the surface of the nickel mesh substrate and increase the sites on the nickel mesh surface that can be electrochemically activated; (2) Using a double-electrode system in an alkaline electrolyte of a certain concentration to perform step potential activation on the pretreated nickel mesh; (3) After activation, the catalyst is thoroughly washed with deionized water, soaked in a cobalt nitrate solution, and finally washed to obtain a high-performance nickel-based catalyst.
[0016] Furthermore, the salt solution is KCl solution.
[0017] Furthermore, the nickel mesh pretreatment temperature is 20-150° C., the KCl solution concentration is 0.1-5M, and the immersion time is 1-24 hours.
[0018] Furthermore, the sandblasted nickel mesh substrate is a single-sided sandblasted nickel mesh or a double-sided sandblasted nickel mesh.
[0019] In an embodiment of the present invention, in step (2), the concentration of the alkaline electrolyte is 0.1M~10M KOH.
[0020] Furthermore, the applied activation potential is 1-6V, the potential increasing gradient is 0.1-1V, and the single potential activation time is 1-60min.
[0021] Furthermore, the concentration of the cobalt nitrate solution is 0.01-2M, and the immersion time is 1-120 min. Example
[0022] The double-sided sandblasted nickel mesh substrate was immersed in 5M KCl solution at a constant temperature of 40°C for 1 hour to corrode the surface of the nickel mesh substrate and increase the sites on the nickel mesh surface that can be electrochemically activated. The pretreated nickel mesh substrate was used as the working electrode, the counter electrode was the unsandblasted nickel-based optical mesh, and the electrolyte was 8M KOH to form a two-electrode system. A 1-2V step potential activation was applied, the potential increase gradient was 0.1V, and the single potential activation time was 5 minutes. The specific step potential application schematic diagram is shown in the figure. Figure 1 As shown, after electrochemical activation, it was immediately immersed in 0.1 M cobalt nitrate solution for 100 min and then rinsed with deionized water.
[0023] Figure 2 The oxygen evolution performance curves of the nickel-based catalyst before and after activation modification in Example 1 are shown. The nickel-based catalyst is subjected to 1 mol / L KOH at a current density of 300 mA / cm2 The oxygen evolution overpotential is 762mV, and the oxygen evolution performance is improved by 107mV compared with before activation. Example
[0024] The double-sided sandblasted nickel mesh substrate was immersed in 3M KCl solution at a constant temperature of 60°C for 4 hours to corrode the surface of the nickel mesh substrate and increase the sites on the nickel mesh surface that can be electrochemically activated. The pretreated nickel mesh substrate was used as the working electrode, and the counter electrode was the unsandblasted nickel-based optical mesh. The electrolyte was 6M KOH to form a two-electrode system. A 1-3V step potential activation was applied, the potential increase gradient was 0.2V, and the single potential activation time was 10min. After electrochemical activation, it was immediately immersed in 0.4M cobalt nitrate solution for 60min and rinsed with deionized water. The prepared nickel-based catalyst had a current density of 300mA / cm under 1mol / L KOH conditions. 2 The oxygen evolution overpotential is 728mV, and the oxygen evolution performance is improved by 122mV compared with before activation.
[0025] Figure 3 The stability test curve of the nickel-based catalyst prepared in Example 2. In a dual-electrode system, the double-sided sandblasted nickel mesh is used as the cathode, the prepared nickel-based catalyst is used as the anode, the electrolyte is 6MKOH, and the constant current density is 300mA / cm 2 Under the conditions of , it ran for 168 hours, and recorded the voltage data every 3 hours. The voltage was stable at around 2.30 V, indicating that the prepared nickel-based catalyst can still maintain good performance in long-term operation. Example
[0026] The double-sided sandblasted nickel mesh substrate was immersed in 1M KCl solution at a constant temperature of 80°C for 8 hours to corrode the surface of the nickel mesh substrate and increase the sites on the nickel mesh surface that can be electrochemically activated. The pretreated nickel mesh substrate was used as the working electrode, and the counter electrode was the unsandblasted nickel-based optical mesh. The electrolyte was 4M KOH to form a two-electrode system. A 2~4V step potential activation was applied, the potential increase gradient was 0.5V, and the single potential activation time was 15 minutes. After electrochemical activation, it was immediately immersed in a 0.8M cobalt nitrate solution for 30 minutes, and then rinsed with deionized water. The prepared nickel-based catalyst has a current density of 300mA / cm under 1mol / L KOH conditions. 2 The oxygen evolution overpotential is 719mV, and the oxygen evolution performance is improved by 125mV compared with before activation. Example
[0027] The double-sided sandblasted nickel mesh substrate was immersed in 0.5M NaOH solution at a constant temperature of 100°C for 12 hours to corrode the surface of the nickel mesh substrate and increase the sites on the nickel mesh surface that can be electrochemically activated. The pretreated nickel mesh substrate was used as the working electrode, and the counter electrode was the unsandblasted nickel-based optical mesh. The electrolyte was 2MKOH to form a two-electrode system. A 3~6V step potential activation was applied, the potential increase gradient was 1V, and the single potential activation time was 20min. After electrochemical activation, it was immediately immersed in 1M cobalt nitrate solution for 10min, and then rinsed with deionized water. The prepared nickel-based catalyst has a current density of 300mA / cm under 1mol / L KOH conditions. 2 The oxygen evolution overpotential is 702mV, and the oxygen evolution performance is improved by 142mV compared with before activation.
[0028] The beneficial effect of the method for preparing a nickel-based modified catalyst by step-by-step electrochemical activation of the present invention is as follows: the nickel-based modified catalyst of the present invention uses a nickel mesh substrate as a nickel source, increases the active sites on the surface of the nickel mesh by applying step potential activation, and subsequently performs cobalt nitrate impregnation to stabilize the activation state of the nickel mesh surface and further enhance its catalytic activity. The method has high economic efficiency, is easy to expand process production, and avoids the problems of low utilization and instability of additional added metal sources.
[0029] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. A method for preparing a nickel-based modified catalyst by stepwise electrochemical activation, characterized in that: The following steps are involved: (1) Soaking the sandblasted nickel mesh substrate in a salt solution at a constant temperature to corrode the surface of the nickel mesh substrate and increase the sites on the nickel mesh surface that can be electrochemically activated; (2) Using a double-electrode system in an alkaline electrolyte to perform step potential activation on the pretreated nickel mesh; (3) After activation, the catalyst is thoroughly washed with deionized water, soaked in a cobalt nitrate solution, and finally washed to obtain a high-performance nickel-based catalyst.
2. The method for preparing a nickel-based modified catalyst by step-by-step electrochemical activation according to claim 1, characterized in that: In step (1), the salt solution is KCl solution.
3. The method for preparing a nickel-based modified catalyst by step-by-step electrochemical activation according to claim 2, characterized in that: In step (1), the nickel mesh pretreatment temperature is 20-150° C., the KCl solution concentration is 0.1-5 M, and the immersion time is 1-24 h.
4. The method for preparing a nickel-based modified catalyst by step-by-step electrochemical activation according to claim 1, characterized in that: The sandblasted nickel mesh substrate is a single-sided sandblasted nickel mesh or a double-sided sandblasted nickel mesh.
5. The method for preparing a nickel-based modified catalyst by step-by-step electrochemical activation according to claim 1, characterized in that: In step (2), the concentration of the alkaline electrolyte is 0.1M~10M KOH.
6. The method for preparing a nickel-based modified catalyst by step-by-step electrochemical activation according to claim 1, characterized in that: In step (2), the activation potential applied is 1-6 V, the potential increasing gradient is 0.1-1 V, and the single potential activation time is 1-60 min.
7. The method for preparing a nickel-based modified catalyst by step-by-step electrochemical activation according to claim 1, characterized in that: In step (3), the concentration of the cobalt nitrate solution is 0.01-2 M, and the immersion time is 1-120 min.