Bimetal-doped and phosphorized nickel-based catalyst and preparation method thereof
By loading molybdenum, vanadium, and phosphorus onto a nickel mesh substrate, a novel nanostructured nickel-based catalyst was formed, solving the problem of high cost of precious metal catalysts and achieving highly efficient hydrogen evolution and oxygen evolution performance, which has broad application prospects.
Patent Information
- Application Number
- CN202510631407.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-16
- Publication Date
- 2025-08-01
AI Technical Summary
In existing alkaline water electrolysis hydrogen production technologies, the high cost and low efficiency of precious metal catalysts limit their widespread application.
A nickel-based catalyst with bimetallic doping and phosphating is used. By loading molybdenum, vanadium and phosphorus elements on a nickel mesh substrate, and utilizing high-temperature reaction and phosphating process, the surface electronic structure is reconstructed to form a new nanostructure, thereby improving the hydrogen evolution and oxygen evolution performance.
Without the addition of precious metals, it significantly improves hydrogen and oxygen evolution performance, has low cost and good stability, and is suitable for alkaline water electrolysis to produce hydrogen.
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Figure CN120400918A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of catalysts for electrolyzing water, and particularly to a bimetal-doped and phosphated nickel-based catalyst and a preparation method thereof. Background Art
[0002] Hydrogen energy is regarded as the core carrier for realizing energy transformation due to its high energy density, zero carbon emission, and rich resources. Hydrogen production by electrolyzing water, especially the "green hydrogen" technology using renewable energy, has become the most promising hydrogen production path due to its easy availability of raw materials and high purity of products.
[0003] Currently, the most maturely developed is alkaline water electrolysis for hydrogen production. However, bottleneck problems such as high cost and low hydrogen production efficiency limit its development. Among them, the cost problem is one of the most challenging issues to be overcome. In alkaline water electrolysis for hydrogen production, electricity costs account for about 74% of the cost. By developing efficient electrocatalysts, the cost can be effectively reduced, thus promoting the development of water electrolysis. Among current electrocatalysts, noble metals such as platinum, iridium, and ruthenium have the lowest overpotential for hydrogen production by electrolyzing water due to their optimal hydrogen adsorption / desorption energy. However, due to the scarce global reserves and high price of noble metals, their development and application are limited. Therefore, the research on non-noble metal electrocatalysts for water electrolysis with rich global reserves and low cost is of great significance. Summary of the Invention
[0004] To solve the above technical problems, one technical solution adopted by the present invention is: Provide a bimetal-doped and phosphated nickel-based catalyst and a preparation method thereof, and the steps include: (1) Pretreat the nickel mesh substrate to remove the oxide layer on the surface of the nickel mesh; (2) Place the pretreated nickel mesh substrate in a solution system containing molybdenum, vanadium elements, and terephthalic acid for high-temperature reaction; (2.1) Dissolve sodium molybdate dihydrate, sodium metavanadate, and terephthalic acid in N,N-dimethylformamide, stir and mix evenly to obtain a mixed solution, such that the concentration of sodium molybdate dihydrate in the mixed solution is 0.5 - 10 mmol, the concentration of sodium metavanadate is 0.1 - 8 mmol, and the concentration of terephthalic acid is 1 - 10 mmol; (2.2) Immerse the nickel mesh substrate in the mixed solution and then transfer it together to a polytetrafluoroethylene inner liner, and then place it in a stainless steel autoclave and heat it in a forced-air drying oven; wherein, the heating temperature is 80 - 300 °C, and the heating time is 10 - 100 h; (3) After the reaction is completed, take out the nickel mesh substrate, wash it thoroughly and dry it; (4) Place the nickel mesh substrate in a phosphorus-containing electrolyte for constant potential activation to complete phosphating; (4.1) Sodium hypophosphite is added to a potassium hydroxide solution to obtain a phosphorus-containing electrolyte, and the concentration of potassium hydroxide in the phosphorus-containing electrolyte is 1-8 M, and the concentration of sodium hypophosphite is 0.01-3 M; (4.2) The nickel mesh substrate is placed in the phosphorus-containing electrolyte, and a potentiostatic activation is carried out using a two-electrode system, and a water bath heating is carried out during the activation process to obtain a phosphated modified nickel-based catalyst; wherein, the applied activation potential is 1-15 V, the activation time is 1-200 min, and the heating temperature is 50-100 °C; (5) The nickel-based catalyst is rinsed with deionized water and dried.
[0005] In a preferred embodiment of the present invention, in step (1), the nickel mesh substrate is first placed in a hydrochloric acid solution with a concentration of 1-5 M for ultrasonic cleaning for 0.5-24 h, and then the nickel mesh substrate is placed in deionized water for ultrasonic cleaning.
[0006] In a preferred embodiment of the present invention, the nickel mesh substrate includes a single-sided sandblasted nickel mesh or a double-sided sandblasted nickel mesh.
[0007] In a preferred embodiment of the present invention, in step (3), the nickel mesh substrate is thoroughly cleaned with absolute ethanol and deionized water.
[0008] In a preferred embodiment of the present invention, in step (2.2), the pressure in the reaction kettle is 1-10 MPa.
[0009] In a preferred embodiment of the present invention, in step (3), the drying time is 1-10 h.
[0010] In a preferred embodiment of the present invention, in step (4.2), the nickel mesh treated in step (3) is used as the working electrode, and the nickel light mesh is used as the counter electrode.
[0011] The beneficial effects of the present invention are as follows: Molybdenum, vanadium and phosphorus elements are loaded on the surface of the nickel mesh substrate. The phosphorus element with extremely strong electronegativity has a strong synergistic effect with the molybdenum and vanadium loaded on the surface of the nickel mesh, effectively adjusting the electronic structure of the active sites on the surface of the nickel mesh and reconstructing the electronic interaction on the surface, thereby effectively improving the hydrogen evolution and oxygen evolution performance and having excellent stability. Moreover, the preparation process is simple, no precious metals are doped, the cost is low, and it has broad application prospects in the field of alkaline electrolytic water hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings, where: Figure 1 It is the surface morphology diagram of the nickel-based catalyst prepared in the present invention magnified 100 times; Figure 2 It is the surface morphology diagram of the nickel-based catalyst prepared in the present invention magnified 2000 times; Figure 3 It is the surface morphology diagram of the nickel-based catalyst prepared in the present invention magnified 20000 times; Figure 4 It is the surface morphology diagram of the nickel-based catalyst prepared in the present invention magnified 50000 times; Figure 5 It is the hydrogen evolution overpotential of the nickel-based catalysts prepared in Examples 1-4 of the present invention; Figure 6 It is the oxygen evolution overpotential of the nickel-based catalysts prepared in Examples 1-4 of the present invention. Detailed Embodiments
[0013] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0014] Please refer to Figures 1-6 , the embodiments of the present invention include: A bimetal-doped and phosphated nickel-based catalyst and its preparation method. Molybdenum, vanadium elements and terephthalic acid are taken as ligands for hydrothermal treatment, and through subsequent phosphating process, a modified nickel-based catalyst is prepared and used for efficient water splitting. The specific steps include: (1) Pretreat the nickel mesh substrate: First, place the nickel mesh substrate in a hydrochloric acid solution with a concentration of 1-5M for ultrasonic cleaning for 0.5-24h, and then place the nickel mesh substrate in deionized water for ultrasonic cleaning to remove the oxide layer on the surface of the nickel mesh.
[0015] Among them, the nickel mesh substrate includes a single-sided sandblasted nickel mesh or a double-sided sandblasted nickel mesh.
[0016] (2) Place the pretreated nickel mesh substrate in a solution system containing molybdenum, vanadium elements and terephthalic acid for high-temperature reaction.
[0017] (2.1) Dissolve sodium molybdate dihydrate, sodium metavanadate and terephthalic acid in N,N-dimethylformamide, and stir and mix evenly to obtain a mixed solution; among them, in the mixed solution, the concentration of sodium molybdate dihydrate is 0.5-10 mmol, the concentration of sodium metavanadate is 0.1-8 mmol, and the concentration of terephthalic acid is 1-10 mmol.
[0018] (2.2) Immerse the nickel mesh substrate in the mixed solution and then transfer them together into a polytetrafluoroethylene liner, and then load it into a stainless-steel autoclave and heat it in a blast drying oven. Among them, the heating temperature is 80~300 °C, and the heating time is 10~100 h.
[0019] (3) After the reaction is completed, take out the nickel mesh substrate, wash it thoroughly with absolute ethanol and deionized water, and dry it for 1 - 10 h.
[0020] (4) Place the nickel mesh substrate in a phosphorus-containing electrolyte for potentiostatic activation.
[0021] (4.1) Add sodium hypophosphite to the potassium hydroxide solution so that the concentration of potassium hydroxide is 1~8 M and the concentration of sodium hypophosphite is 0.01~3 M to obtain a phosphorus-containing electrolyte.
[0022] (4.2) Place the nickel mesh substrate in the phosphorus-containing electrolyte, perform potentiostatic activation using a two-electrode system, and carry out water bath heating during the activation process to obtain a phosphated modified nickel-based catalyst; among them, the applied activation potential is 1~15 V, the activation time is 1~200 min, and the heating temperature is 50 - 100 °C.
[0023] Phosphorus has a greater electronegativity, which will make the metal more electron-deficient. Therefore, new nanostructures will be formed on the surface of the phosphated nickel mesh substrate, changing the active sites on the surface of the nickel mesh, which is more conducive to the occurrence of HER and OER reactions, thus achieving the purpose of improving the hydrogen evolution and oxygen evolution performance of the modified nickel-based catalyst, and without doping precious metals, the cost is relatively low.
[0024] (5) Rinse the nickel-based catalyst with deionized water and dry it. Example
[0025] The nickel mesh substrate with double-sided sandblasting was ultrasonically cleaned in a 5M hydrochloric acid solution at room temperature for 2 h, and then ultrasonically cleaned in deionized water for 4 h to remove the oxide layer on the surface of the nickel mesh substrate, so as to fully carry out electrochemical activation subsequently; Sodium molybdate dihydrate, sodium metavanadate and terephthalic acid were dissolved in N,N-dimethylformamide, stirred and mixed evenly, and the concentration of sodium molybdate dihydrate was 1 mmol, the concentration of sodium metavanadate was 1.5 mmol, and the concentration of terephthalic acid was 2 mmol; The pretreated nickel mesh substrate was placed in a solution system containing molybdenum, vanadium elements and terephthalic acid, then transferred to a polytetrafluoroethylene liner, and then loaded into a stainless steel autoclave, and heated in a blast drying oven, the heating temperature was set at 150 °C, and the heating time was 12 h; After the reaction, the nickel mesh was taken out and washed thoroughly with absolute ethanol and deionized water, and dried for 2 h; Sodium hypophosphite was added to the potassium hydroxide solution to obtain a phosphorus-containing electrolyte, and the concentration of potassium hydroxide was 2M and the concentration of sodium hypophosphite was 0.05M. Subsequently, the treated nickel mesh was used as the working electrode and the nickel light mesh was used as the counter electrode to form a two-electrode system and placed in the phosphorus-containing electrolyte, and a constant potential of 1.5V was applied for activation for 160 min. The activation process was carried out with water bath heating, and the temperature was set at 50 °C; The nickel mesh after phosphidation was rinsed with deionized water and dried.
[0026] As Figures 1-4 shown, new nanostructures appear on the surface of the nickel-based catalyst. When magnified 50,000 times, it is observed that it presents a spherical nanostructure, increasing its catalyst surface area.
[0027] As Figures 5-6 shown, under the condition of 1mol / L KOH, the hydrogen evolution overpotential of the nickel-based catalyst with a current density of 300 mA / cm 2 is 268 mV, and the oxygen evolution overpotential is 322 mV. Compared with that before modification, the hydrogen evolution performance is improved by 169 mV, and the oxygen evolution performance is improved by 182 mV. Example
[0028] The double-sided sandblasted nickel mesh substrate was ultrasonically cleaned with a 3M hydrochloric acid solution at room temperature for 4 hours, and then ultrasonically cleaned in deionized water for 3 hours to remove the oxide layer on the surface of the nickel mesh substrate so that it can be fully electrochemically activated later; sodium molybdate dihydrate, sodium metavanadate and terephthalic acid were dissolved in N,N-dimethylformamide and stirred and mixed evenly to make the concentration of sodium molybdate dihydrate 2mmol, the concentration of sodium metavanadate 3mmol, and the concentration of terephthalic acid 4mmol. The pretreated nickel mesh substrate was placed in a solution system containing molybdenum, vanadium elements and terephthalic acid, and then transferred to a polytetrafluoroethylene liner, and then placed in a stainless steel high-pressure The nickel mesh was placed in a reactor and heated in a forced air drying oven with the heating temperature set to 180°C for 16 hours. After the reaction was completed, the nickel mesh was removed and thoroughly washed with anhydrous ethanol and deionized water, and dried for 4 hours. Sodium hypophosphite was added to the potassium hydroxide solution to obtain a phosphorus-containing electrolyte, and the concentration of potassium hydroxide was 4M and the concentration of sodium hypophosphite was 0.5M. Subsequently, the treated nickel mesh was used as the working electrode and the nickel optical mesh as the counter electrode to form a double electrode system and placed in the phosphorus-containing electrolyte. A constant potential of 2V was applied for activation for 180 minutes. The activation process was carried out by water bath heating with the temperature set to 70°C. The phosphated nickel mesh was rinsed with deionized water and then dried.
[0029] like Figures 5-6 As shown in the figure, the nickel-based catalyst has a current density of 300 mA / cm under 1 mol / L KOH conditions. 2 The hydrogen evolution overpotential is 304mV, and the oxygen evolution overpotential is 373mV. Compared with before modification, the hydrogen evolution performance is improved by 133mV and the oxygen evolution performance is improved by 131mV. Example
[0030] The nickel mesh substrate with double-sided sandblasting was ultrasonically cleaned in a 2M hydrochloric acid solution at room temperature for 6 h, and then ultrasonically cleaned in deionized water for 2 h to remove the oxide layer on the surface of the nickel mesh substrate for subsequent full electrochemical activation; sodium molybdate dihydrate, sodium metavanadate, and terephthalic acid were dissolved in N,N-dimethylformamide and stirred and mixed evenly so that the concentration of sodium molybdate dihydrate was 4 mmol, the concentration of sodium metavanadate was 5 mmol, and the concentration of terephthalic acid was 6 mmol. The pretreated nickel mesh substrate was placed in a solution system containing molybdenum, vanadium elements, and terephthalic acid, then transferred to a polytetrafluoroethylene inner liner, and then loaded into a stainless steel autoclave and heated in a blast drying oven. The heating temperature was set at 200 °C and the heating time was 20 h; after the reaction was completed, the nickel mesh was taken out and washed thoroughly with absolute ethanol and deionized water and dried for 6 h; sodium hypophosphite was added to the potassium hydroxide solution so that the concentration of potassium hydroxide was 6M and the concentration of sodium hypophosphite was 1M. Subsequently, the treated nickel mesh was used as the working electrode and the nickel light mesh was used as the counter electrode to form a two-electrode system and placed in a phosphorus-containing electrolyte solution, and a constant potential of 4V was applied for activation for 210 min. The activation process was heated in a water bath, and the temperature was set at 80 °C. The phosphated nickel mesh was rinsed with deionized water and dried after being washed clean.
[0031] As Figures 5-6 shown, under the condition of 1 mol / L KOH, the hydrogen evolution overpotential of this nickel-based catalyst was 236 mV at a current density of 300 mA / cm 2 , and the oxygen evolution overpotential was 279 mV. Compared with that before modification, the hydrogen evolution performance was improved by 201 mV, and the oxygen evolution performance was improved by 225 mV. Example
[0032] The nickel mesh substrate with double-sided sandblasting was ultrasonically cleaned with 1M hydrochloric acid solution at room temperature for 8 h, and then ultrasonically cleaned in deionized water for 1 h to remove the oxide layer on the surface of the nickel mesh substrate, so as to fully carry out electrochemical activation subsequently; Sodium molybdate dihydrate, sodium metavanadate and terephthalic acid were dissolved in N,N-dimethylformamide and stirred and mixed evenly. The concentration of sodium molybdate dihydrate was 6 mmol, the concentration of sodium metavanadate was 7 mmol, and the concentration of terephthalic acid was 8 mmol. The pretreated nickel mesh substrate was placed in a solution system containing molybdenum, vanadium elements and terephthalic acid, and then transferred to a polytetrafluoroethylene inner liner, and then loaded into a stainless steel autoclave and heated in a forced air drying oven. The heating temperature was set at 220 °C and the heating time was 22 h; After the reaction was completed, the nickel mesh was taken out and washed thoroughly with absolute ethanol and deionized water, and dried for 8 h; Sodium hypophosphite was added to the potassium hydroxide solution, and the concentration of potassium hydroxide was 8M and the concentration of sodium hypophosphite was 2M. Subsequently, the treated nickel mesh was used as the working electrode and the nickel light mesh was used as the counter electrode to form a two-electrode system and placed in a phosphorus-containing electrolyte, and a constant potential of 6V was applied for activation for 240 min. The activation process was carried out with water bath heating, and the temperature was set at 90 °C. The phosphated nickel mesh was rinsed with deionized water and dried after being rinsed clean.
[0033] As Figures 5-6 shown, under the condition of 1 mol / L KOH, the hydrogen evolution overpotential of this nickel-based catalyst with a current density of 300 mA / cm 2 is 375 mV, and the oxygen evolution overpotential is 423 mV. Compared with that before modification, the hydrogen evolution performance is improved by 62 mV, and the oxygen evolution performance is improved by 81 mV.
[0034] The beneficial effects of a bimetal-doped and phosphated nickel-based catalyst and its preparation method of the present invention are as follows: (1) In the present invention, a nickel mesh is used as the substrate, and molybdenum, vanadium and phosphorus elements are added to its surface, effectively regulating the electronic structure of the active sites on the surface of the nickel mesh, reconstructing the electronic interaction on the surface, and affecting the state of adsorbed hydrogen at its active center, thereby effectively improving the hydrogen evolution performance; (2) In the present invention, molybdenum and vanadium elements are loaded on the surface of the nickel mesh to form a new nanostructure. After phosphating, the phosphorus element with extremely strong electronegativity has a strong synergistic effect with the molybdenum and vanadium loaded on the surface of the nickel mesh, forming more stable molybdenum and vanadium phosphides, which is beneficial to the oxygen evolution reaction process.
[0035] (3) The nickel-based catalyst prepared by bimetal doping and phosphating in the present invention does not dope precious metals, has a low cost, and the modified nickel-based catalyst has excellent stability and broad application prospects in the field of alkaline electrolytic water hydrogen production.
[0036] The above are only embodiments of the present invention, and do not thus limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, shall similarly be included within the patent protection scope of the present invention.
Claims
1. A bimetal-doped and phosphated nickel-based catalyst and its preparation method, characterized in that the steps Including: (1) Pretreat the nickel mesh substrate to remove the oxide layer on the surface of the nickel mesh; (2) Place the pretreated nickel mesh substrate in a solution system containing molybdenum, vanadium elements and terephthalic acid for high-temperature reaction; (2.1) Dissolve sodium molybdate dihydrate, sodium metavanadate and terephthalic acid in N,N-dimethylformamide, stir and mix evenly to obtain a mixed solution, so that the concentration of sodium molybdate dihydrate in the mixed solution is 0.5 - 10 mmol, the concentration of sodium metavanadate is 0.1 - 8 mmol, and the concentration of terephthalic acid is 1 - 10 mmol; (2.2) Immerse the nickel mesh substrate in the mixed solution and then transfer them together into a polytetrafluoroethylene liner, then load them into an autoclave and heat them in a forced-air drying oven; wherein, the heating temperature is 80 - 300 °C and the heating time is 10 - 100 h; (3) After the reaction is completed, take out the nickel mesh substrate, wash it thoroughly and dry it; (4) Place the nickel mesh substrate in a phosphorus-containing electrolyte for potentiostatic activation to complete phosphating; (4.1) Add sodium hypophosphite to the potassium hydroxide solution to obtain a phosphorus-containing electrolyte, and make the concentration of potassium hydroxide in the phosphorus-containing electrolyte be 1 - 8 M and the concentration of sodium hypophosphite be 0.01 - 3 M; (4.2) Place the nickel mesh substrate in the phosphorus-containing electrolyte, carry out potentiostatic activation using a two-electrode system, and perform water bath heating during the activation process to obtain a phosphated modified nickel-based catalyst; wherein, the applied activation potential is 1 - 15 V, the activation time is 1 - 200 min, and the heating temperature is 50 - 100 °C; (5) Rinse the nickel-based catalyst with deionized water and dry it.
2. The bimetal-doped and phosphated nickel-based catalyst according to claim 1 and its preparation method, characterized in that, In step (1), first place the nickel mesh substrate in a hydrochloric acid solution with a concentration of 1 - 5 M for ultrasonic cleaning for 0.5 - 24 h, and then place the nickel mesh substrate in deionized water for ultrasonic cleaning.
3. A bimetal-doped and phosphated nickel-based catalyst and a preparation method thereof according to claim 1, characterized in that, The nickel mesh substrate includes a single-sided sandblasted nickel mesh or a double-sided sandblasted nickel mesh.
4. A bimetal-doped and phosphated nickel-based catalyst and its preparation method according to claim 1, characterized in that, In step (2.2), the pressure in the autoclave is 1 - 10 MPa.
5. A bimetal-doped and phosphated nickel-based catalyst and a preparation method thereof according to claim 1, characterized in that, In step (3), wash the nickel mesh substrate thoroughly with absolute ethanol and deionized water.
6. A bimetal-doped and phosphated nickel-based catalyst and a preparation method thereof according to claim 1, characterized in that, In step (3), the drying time is 1 - 10 h.
7. A bimetal-doped and phosphated nickel-based catalyst and a preparation method thereof according to claim 1, characterized in that, In step (4.2), the nickel mesh after being treated in step (3) serves as the working electrode, and the nickel light mesh serves as the counter electrode.