Nickel-based catalyst based on constant potential activation and calcination curing and preparation method thereof
Through constant potential activation and calcining curing methods, the oxygen evolution performance and stability of nickel-based catalysts are improved, and the problems of insufficient and unstable performance of existing nickel-based catalysts are solved, and efficient and economical catalytic performance improvement is achieved.
Patent Information
- Application Number
- CN202510167767.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-17
- Publication Date
- 2025-05-06
AI Technical Summary
The existing nickel-based catalysts have insufficient catalytic performance in electrolytic water hydrogen production system and are unstable in high concentration alkali liquid, resulting in the catalyst layer falling off and low utilization rate.
Pretreatment is performed by immersing the nickel mesh substrate in a heated NaCl solution, followed by constant potential activation in the alkaline electrolyte and calcining and curing at high temperature to form a high performance nickel-based catalyst.
This method effectively improves the oxygen evolution performance and stability of nickel-based catalysts, avoids the need for additional catalysts, reduces costs, and maintains the stability of the catalyst in high concentration alkali liquid.
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Figure CN119932601A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of catalysts for hydrogen evolution by electrolysis of water, and in particular to a nickel-based catalyst based on constant potential activation and calcination solidification and a preparation method thereof. Background Art
[0002] In recent years, the demand for hydrogen has been growing as an important chemical raw material and energy carrier. 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.
[0003] At present, the nickel mesh substrate used in the actual water electrolysis hydrogen production system needs to be loaded with high-performance catalysts through thermal spraying, plasma spraying and other methods. There are many related studies focusing on the methods of loading catalysts and the types of loaded catalysts, but there is no research on improving the performance of nickel-based catalysts without adding additional catalysts. 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 alkali solution. Summary of the invention
[0004] In order to solve the above technical problems, a technical solution adopted by the present invention is: Provided is a method for preparing a nickel-based catalyst based on constant potential activation and calcination solidification, comprising: (1) Soaking the nickel mesh substrate in a heated NaCl solution for 0.5 to 12 hours for pretreatment; (2) immersing the pretreated nickel mesh substrate in an alkaline electrolyte, and applying a constant potential to the nickel mesh substrate using a double electrode system to perform constant potential activation; wherein the applied constant activation potential is 1 to 10 V, and the activation time is 1 to 120 min; (3) After the activation reaction is completed, remove the nickel mesh substrate and wash it thoroughly with deionized water; (4) The cleaned nickel mesh substrate is placed in a muffle furnace for calcination and curing at a temperature of 150-500°C for a time of 1-200 min, so as to convert the unstable sites on the surface of the nickel mesh after constant potential activation into stable active sites, stabilize the activation performance, and thus prepare a high-performance nickel-based catalyst.
[0005] In a preferred embodiment of the present invention, the nickel mesh substrate includes a smooth nickel mesh, a single-sided sandblasted nickel mesh, or a double-sided sandblasted nickel mesh.
[0006] In a preferred embodiment of the present invention, in step (1), the NaCl solution is heated to 20-120° C., and the concentration of the NaCl solution is 1-10M.
[0007] In a preferred embodiment of the present invention, in step (2), the alkaline electrolyte includes a KOH solution or a NaOH solution.
[0008] In a preferred embodiment of the present invention, the concentration of the alkaline electrolyte is 1-6M.
[0009] In a preferred embodiment of the present invention, in step (3), the cleaned nickel mesh substrate is placed in an oven for drying.
[0010] A nickel-based catalyst based on constant potential activation and calcination solidification is prepared by any of the above methods and is used as an anode for electrolyzing water to produce hydrogen.
[0011] The beneficial effects of the present invention are: using the nickel mesh substrate as the nickel source, applying a constant potential activation, increasing the active sites on the surface of the nickel mesh, and subsequently performing high-temperature calcination and curing to stabilize the activated sites on the surface of the nickel mesh, thereby effectively improving the oxygen evolution performance of the prepared catalyst and also improving the stability of the performance, which is beneficial to cost control, high economy and high production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] 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 is a schematic diagram of potential application during constant potential activation 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 of the present invention. DETAILED DESCRIPTION
[0013] 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.
[0014] See also Figure 1-3 , the embodiment of the present invention includes: A method for preparing a nickel-based catalyst based on constant potential activation and calcination solidification, the steps comprising: (1) Pretreatment of nickel mesh.
[0015] Further preferably, the nickel mesh is a smooth nickel mesh, a single-sided sandblasted nickel mesh or a double-sided sandblasted nickel mesh.
[0016] Further preferably, the specific steps of pretreating the nickel mesh include: immersing the nickel mesh in a NaCl solution, and heating the NaCl solution to 20-120° C., the concentration of the NaCl solution is 1-10 M, and the immersion time is 0.5-12 h.
[0017] (2) The pretreated nickel mesh is immersed in an alkaline electrolyte, and a constant potential is applied to the nickel mesh using a double electrode system for a certain period of time to perform constant potential activation.
[0018] Further preferably, the alkaline electrolyte includes a KOH solution or a NaOH solution with a concentration of 1-6M.
[0019] More preferably, the constant activation potential applied is 1-10 V, and the activation time is 1-120 min.
[0020] (3) After the activation reaction is completed, remove the nickel mesh, rinse it thoroughly with deionized water, and then dry it.
[0021] (4) The nickel mesh is placed in a muffle furnace for calcination and curing at a temperature of 150 to 500°C for a time of 1 to 200 min, so as to convert the unstable sites on the surface of the nickel mesh after constant potential activation into stable active sites, stabilize the activation performance, and thus prepare a high-performance nickel-based catalyst.
[0022] This nickel-based catalyst activates the nickel mesh substrate by applying a constant potential without adding any additional catalyst, and calcines it to form stable active sites, thereby improving its oxygen evolution performance. This can not only effectively reduce the cost of the electrode catalyst, but also prevent the catalyst coating from falling off in a strong alkaline environment, thereby improving the stability of the catalytic performance and facilitating the sustainable development of hydrogen production technology by water electrolysis. Example
[0023] The polished nickel mesh substrate was immersed in an 8M NaCl solution at a constant temperature of 30°C for 1 hour to corrode the oxide layer on the surface of the polished nickel mesh substrate so as to fully perform electrochemical activation later; the pretreated nickel mesh substrate was used as the working electrode, the counter electrode was a platinum sheet, and the electrolyte was a 1M KOH solution to form a two-electrode system. A constant potential of 1V was applied and activated for 120 minutes. The potential application schematic diagram is shown in FIG. Figure 1As shown; the nickel mesh after electrochemical activation is rinsed with deionized water and then dried, and immediately placed in a muffle furnace for calcination and curing. The calcination temperature is 500°C and the calcination time is 20 minutes. After the calcination, a nickel-based catalyst is obtained.
[0024] Figure 2 The oxygen evolution performance curve of the nickel-based catalyst prepared in Example 1 is shown in Figure 1. The nickel-based catalyst is used as the electrolyte under the condition of 1 mol / L KOH solution and the current density is 300 mA / cm 2 The oxygen evolution overpotential is 780mV, and the oxygen evolution performance is improved by 103mV compared with before activation. Example
[0025] The single-sided sandblasted nickel mesh substrate was immersed in a 6M NaCl solution at a constant temperature of 50°C for 4 hours to corrode the oxide layer on the surface of the nickel mesh substrate so as to fully perform electrochemical activation later; the pretreated nickel mesh substrate was used as the working electrode, the counter electrode was a platinum sheet, and the electrolyte was a 2M KOH solution to form a two-electrode system, and a 2V constant potential was applied for activation for 60 minutes; the electrochemically activated nickel mesh was rinsed with deionized water and then dried, and immediately placed in a muffle furnace for calcination and curing, the calcination temperature was 400°C, and the calcination time was 40 minutes.
[0026] The prepared nickel-based catalyst has a current density of 300 mA / cm under 1 mol / L KOH conditions. 2 The oxygen evolution overpotential is 722mV, and the oxygen evolution performance is improved by 118mV compared with before activation.
[0027] 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 6M KOH solution, and the constant current density is 300mA / cm 2 Under the conditions of , it ran for 168 hours, and the voltage data was recorded every 3 hours. The voltage was stable at around 2.20 V, indicating that the prepared nickel-based catalyst can still maintain good performance in long-term operation. Example
[0028] The double-sided sandblasted nickel mesh substrate was immersed in 4M NaCl solution at a constant temperature of 80°C for 8 hours to corrode the oxide layer on the surface of the nickel mesh substrate so as to fully perform electrochemical activation later; the pretreated nickel mesh substrate was used as the working electrode, the counter electrode was a platinum sheet, and the electrolyte was a 4M KOH solution to form a two-electrode system, and a 4V constant potential was applied for activation for 30 minutes; the nickel mesh after electrochemical activation was rinsed with deionized water and then dried, and immediately placed in a muffle furnace for calcination and curing, the calcination temperature was 300°C, and the calcination time was 60 minutes.
[0029] The prepared nickel-based catalyst has a current density of 300 mA / cm under 1 mol / L KOH conditions. 2 The oxygen evolution overpotential is 709mV, and the oxygen evolution performance is improved by 126mV compared with before activation. Example
[0030] The double-sided sandblasted nickel mesh substrate was immersed in a 2M NaCl solution at a constant temperature of 100°C for 12 hours to corrode the oxide layer on the surface of the nickel mesh substrate so as to fully perform electrochemical activation later; the pretreated nickel mesh substrate was used as the working electrode, the counter electrode was a platinum sheet, and the electrolyte was 6M KOH to form a two-electrode system, and a 6V constant potential was applied for activation for 10 minutes; the nickel mesh after electrochemical activation was rinsed with deionized water and then dried, and immediately placed in a muffle furnace for calcination and curing, the calcination temperature was 200°C, and the calcination time was 80 minutes.
[0031] The prepared nickel-based catalyst has a current density of 300 mA / cm under 1 mol / L KOH conditions. 2 The oxygen evolution overpotential is 687mV, and the oxygen evolution performance is improved by 141mV compared with before activation.
[0032] The nickel-based catalyst based on constant potential activation and calcination solidification and the preparation method thereof have the following beneficial effects: 1. Using the nickel mesh substrate as the nickel source, the active sites on the surface of the nickel mesh are increased by applying a constant potential activation. In order to stabilize the activation sites on the surface of the nickel mesh, high-temperature calcination and curing are subsequently performed to effectively improve the oxygen evolution performance of the prepared catalyst.
[0033] 2. The method of constant potential activation and calcination solidification for preparing nickel-based catalysts is highly practical and avoids the problems of low utilization and instability caused by the additional addition of metal sources. It is highly economical and easy to expand process production.
[0034] 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 catalyst based on constant potential activation and calcination solidification, characterized in that: include: (1) Soaking the nickel mesh substrate in a heated NaCl solution for 0.5 to 12 hours for pretreatment; (2) immersing the pretreated nickel mesh substrate in an alkaline electrolyte, and applying a constant potential to the nickel mesh substrate using a double electrode system to perform constant potential activation; wherein the applied constant activation potential is 1 to 10 V, and the activation time is 1 to 120 min; (3) After the activation reaction is completed, remove the nickel mesh substrate and wash it thoroughly with deionized water; (4) The cleaned nickel mesh substrate is placed in a muffle furnace for calcination and curing at a temperature of 150-500°C for a time of 1-200 min, so as to convert the unstable sites on the surface of the nickel mesh after constant potential activation into stable active sites, stabilize the activation performance, and thus prepare a high-performance nickel-based catalyst.
2. The method for preparing a nickel-based catalyst based on constant potential activation and calcination solidification according to claim 1, characterized in that: The nickel mesh substrate includes a smooth nickel mesh, a single-sided sandblasted nickel mesh or a double-sided sandblasted nickel mesh.
3. The method for preparing a nickel-based catalyst based on constant potential activation and calcination solidification according to claim 1, characterized in that: In step (1), the NaCl solution is heated to 20-120° C., and the concentration of the NaCl solution is 1-10 M.
4. The method for preparing a nickel-based catalyst based on constant potential activation and calcination solidification according to claim 1, characterized in that: In step (2), the alkaline electrolyte includes a KOH solution or a NaOH solution.
5. The method for preparing a nickel-based catalyst based on constant potential activation and calcination solidification according to claim 4, characterized in that: The concentration of the alkaline electrolyte is 1-6M.
6. The method for preparing a nickel-based catalyst based on constant potential activation and calcination solidification according to claim 1, characterized in that: In step (3), the cleaned nickel mesh substrate is placed in an oven for drying.
7. A nickel-based catalyst based on constant potential activation and calcination solidification, characterized in that: Prepared by any method of claims 1-4, used as an anode for producing hydrogen by electrolysis of water.