Preparation method of Ce-CoP / NiCoP-NF catalyst
By introducing rare earth element cerium into the transition metal phosphide, adjusting its electronic structure, and preparing Ce-CoP/NiCoP-NF catalysts, the existing electrolytic catalysts have been solved, and the efficient and stable electrolytic hydrogen production effect is achieved.
Patent Information
- Application Number
- CN202510298236.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-13
- Publication Date
- 2025-05-06
AI Technical Summary
The existing electrolytic water catalyst has high cost and low reserves, and the long-term corrosion resistance and electrocatalytic performance of transition metal phosphides are insufficient, which limits its application in the field of electrolytic hydrogen production.
By introducing the rare earth element cerium, adjusting the geometric configuration and electronic arrangement of transition metal phosphides, Ce-CoP/NiCoP-NF catalyst is prepared to improve its conductivity and stability.
It realizes efficient catalytic activity and stability of hydrogen production by electrolyzing water, reduces the production cost of the catalyst, and has high practical value.
Smart Images
Figure CN119932630A_ABST
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 Ce-CoP / NiCoP-NF catalyst. Background Art
[0002] Hydrogen production by water electrolysis (HER) is considered a sustainable option for large-scale energy conversion and storage using renewable energy sources such as solar, wind and hydropower. Currently, precious metal catalysts are still the best performing water electrolysis catalysts, but their high price and small reserves greatly limit their large-scale application. Therefore, the development of high-efficiency, low-cost non-precious metal catalysts is the key to solving the current bottleneck in the development of water electrolysis. In recent years, transition metal phosphides (TMPs) have attracted increasing attention due to their abundant raw material sources, low prices and outstanding catalytic activity. Among them, nickel cobalt phosphide (NiCoP) and cobalt phosphide (CoP) have been identified as potential electrocatalysts with excellent catalytic activity for hydrogen evolution. Both the phosphorus sites and metal centers in TMPs can serve as active sites for the catalytic process, resulting in the material having significant catalytic activity. However, the long-term corrosion resistance, electrocatalytic performance and practical industrial applications of TMPs are often unsatisfactory. Summary of the invention
[0003] The purpose of the present invention is to provide a method for preparing a Ce-CoP / NiCoP-NF catalyst, which helps to adjust the geometric configuration and electronic arrangement of the transition metal phosphide material by introducing rare earth elements, thereby improving the conductivity of the catalytic material. In addition, the rare earth elements stabilize the reaction intermediates in the HER catalytic process, thereby further improving the stability of the catalyst. Therefore, the present invention provides a method for preparing a Ce-CoP / NiCoP-NF catalyst, which has excellent HER catalytic activity and stability.
[0004] To achieve the above object, the present invention provides the following technical solutions:
[0005] A method for preparing a Ce-CoP / NiCoP-NF catalyst comprises the following steps:
[0006] Step 1: Add nickel salt, cobalt salt, cerium salt, ammonium fluoride and urea into deionized water to prepare a mixed solution;
[0007] Step 2: transferring the mixed solution produced in the first step into a reactor, and placing the substrate into the reactor for hydrothermal reaction to prepare a nickel-cobalt-cerium composite precursor;
[0008] Step 3: placing the dried nickel-cobalt-cerium composite precursor and the phosphorus source in a tube furnace and phosphating them under a nitrogen atmosphere to obtain a Ce-CoP / NiCoP-NF catalyst.
[0009] In one embodiment, the substrate is one of nickel foam, nickel-iron foam, copper foam, nickel mesh and nickel felt.
[0010] In one embodiment, the phosphorus source is one of triphenylphosphine, sodium phosphite and sodium hypophosphite.
[0011] In one embodiment, the nickel salt, cobalt salt and cerium salt are nitrates, sulfates or chlorides containing nickel, cobalt and cerium.
[0012] In one embodiment, the nickel salt, cobalt salt and cerium salt are Ni(NO3)2·6H2O, Co(NO3)2·6H2O and Ce(NO3)3·6H2O respectively.
[0013] In one embodiment, the molar ratio of the nickel salt, the cobalt salt, the cerium salt, the ammonium fluoride and the urea is (0.05-0.2):(0.1-0.25):(0.01-0.03):2:1.
[0014] In one embodiment, the temperature of the hydrothermal reaction is 80-150° C. and the time is 6-8 hours.
[0015] In one embodiment, during phosphating, the tube furnace is heated to 250-400° C. at a heating rate of 2-5° C. / min and kept at this temperature for 0.5-4 hours.
[0016] In one embodiment, the steps include:
[0017] Step 1: Using nickel foam as a substrate, ultrasonic cleaning was performed in 3M HCl, acetone and ethanol for 30 minutes, and then the cleaned nickel foam was vacuum dried at 60°C for 12 hours;
[0018] Step 2: Dissolve 0.6mmol Ni(NO3)2·6H2O, 1.2mmol Co(NO3)2·6H2O, 0.12mmol Ce(NO3)3·6H2O, 12mmol CO(NH2)2 and 6mmol NH4F in 40mL deionized water, and stir the solution evenly using a magnetic stirrer; then transfer the mixed solution to a 100mL stainless steel autoclave lined with Teflon, and immerse the nickel foam cleaned in the first step into the reaction solution, keep it at 120°C for 8 hours, and after the autoclave is naturally cooled to room temperature, take out the nickel foam coated with the pink-purple material, then, use distilled water and anhydrous ethanol for ultrasonic cleaning, and then fully dry it in a vacuum drying oven at 60°C;
[0019] Step 3: Place 200 mg of triphenylphosphine and the nickel foam produced in the second step at the upstream and downstream of the tube furnace respectively, then flush with nitrogen at a flow rate of 150 sccm for 10 minutes, and then heat the tube furnace to 350°C at a heating rate of 2°C / min at a flow rate of 60 sccm, and keep it warm for 2 hours. Finally, collect the phosphating substrate to obtain the Ce-CoP / NiCoP-NF catalyst.
[0020] Compared with the prior art, the present invention has the following advantages or beneficial effects:
[0021] The present invention synthesizes a foamed nickel-based self-supporting rare earth cerium-doped CoPNiCoP catalyst through an innovative hydrothermal method and low-temperature phosphating strategy. The catalyst has a unique rod-like structure, which can provide a large reaction area, which is not only conducive to full contact with the electrolyte, but also can accelerate the rapid diffusion of gas products, thereby promoting electron transfer and mass transfer. The CoPNNiCoP interface with high activity for HER may lead to electron transfer between the two phases, and the modulation of this electronic structure also produces more active sites at the interface. These active sites may have the best adsorption / desorption free energy of intermediates / products in the HER process. The doping of Ce elements can adjust the electronic structure of CoP and NiCoP, thereby improving their catalytic activity. At the same time, the introduction of Ce elements helps to enhance the conductivity of the catalyst and increase the number of reactive sites, thereby promoting the efficient electrolysis of water. When used as a catalyst, it exhibits good electrocatalytic activity and stability under alkaline conditions. The preparation method is simple, the raw materials are easily available, and it has high practical value, which is of great significance for the design, preparation and application of catalysts. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 is a scanning electron microscope image of the Ce-CoP / NiCoP-NF catalyst of the present invention;
[0023] Figure 2 It is a local scanning electron microscope image of the Ce-CoP / NiCoP-NF catalyst in the present invention;
[0024] Figure 3 It is a hydrogen evolution performance diagram of the embodiment and the comparative example in the present invention;
[0025] Figure 4 This is a diagram showing the stability effect of Ce-CoP / NiCoP-NF in the present invention. DETAILED DESCRIPTION
[0026] 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.
[0027] Example 1
[0028] 01. Nickel foam (3 cm × 2 cm) was used as the substrate and ultrasonically cleaned in 3M HCl, acetone and ethanol for 30 minutes, and then the cleaned nickel foam was vacuum dried at 60°C for 12 hours;
[0029] 02. Dissolve 0.6mmol Ni(NO3)2·6H2O, 1.2mmol Co(NO3)2·6H2O, 0.12mmol Ce(NO3)3·6H2O, 12mmol CO(NH2)2 and 6mmol NH4F in 40mL deionized water, stir the solution evenly with a magnetic stirrer, then transfer the mixed solution to a 100mL stainless steel autoclave lined with Teflon, and immerse the clean nickel foam in the reaction solution, keep it at 120℃ for 8 hours, and after the autoclave is naturally cooled to room temperature, take out the nickel foam coated with pink-purple material, then, use distilled water and anhydrous ethanol for ultrasonic cleaning, and then fully dry it in a vacuum drying oven at 60℃;
[0030] 03. Place 200 mg of triphenylphosphine and the nickel foam produced in the second step upstream and downstream of the tube furnace respectively. Then, flush with nitrogen at a flow rate of 150 sccm for 10 minutes. Then, heat the tube furnace to 350°C at a heating rate of 2°C / min at a flow rate of 60 sccm and keep it warm for 2 hours. Finally, collect the phosphating substrate and record it as Ce-CoP / NiCoP-NF.
[0031] Example 2
[0032] Nickel foam (3 cm × 2 cm) was used as the substrate and cleaned by ultrasonic treatment in 3 M HCl, acetone and ethanol for 30 min. The cleaned nickel foam was then vacuum dried at 60 °C for 12 h.
[0033] 02. Dissolve 0.6mmol Ni(NO3)2·6H2O, 1.2mmol Co(NO3)2·6H2O, 0.12mmol Ce(NO3)3·6H2O, 12mmol CO(NH2)2 and 6mmol NH4F in 40mL deionized water, stir the solution evenly with a magnetic stirrer, then transfer the mixed solution to a 100mL stainless steel autoclave lined with Teflon, and immerse the clean nickel foam in the reaction solution, keep it at 150℃ for 8 hours, and after the autoclave is naturally cooled to room temperature, take out the nickel foam coated with pink-purple material, then, use distilled water and anhydrous ethanol ultrasonic cleaning, and then fully dry it in a vacuum drying oven at 60℃;
[0034] 03. Place 200 mg of triphenylphosphine and the nickel foam produced in the second step upstream and downstream of the tube furnace respectively. Then, flush with nitrogen at a flow rate of 150 sccm for 10 minutes. Then, heat the tube furnace to 350°C at a heating rate of 2°C / min at a flow rate of 60 sccm and keep it warm for 2 hours. Finally, collect the phosphating substrate and record it as Ce-CoP / NiCoP-NF-1.
[0035] Example 3
[0036] 01. Nickel foam (3 cm × 2 cm) was used as the substrate and ultrasonically cleaned in 3M HCl, acetone and ethanol for 30 minutes, and then the cleaned nickel foam was vacuum dried at 60°C for 12 hours;
[0037] 02. Dissolve 0.6mmol Ni(NO3)2·6H2O, 1.2mmol Co(NO3)2·6H2O, 0.12mmol Ce(NO3)3·6H2O, 12mmol CO(NH2)2 and 6mmol NH4F in 40mL deionized water, stir the solution evenly with a magnetic stirrer, then transfer the mixed solution to a 100mL stainless steel autoclave lined with Teflon, and immerse the clean nickel foam in the reaction solution, keep it at 80℃ for 8 hours, and after the autoclave is naturally cooled to room temperature, take out the nickel foam coated with pink-purple material, then, use distilled water and anhydrous ethanol ultrasonic cleaning, and then fully dry it in a vacuum drying oven at 60℃;
[0038] 03. Place 200 mg of triphenylphosphine and the nickel foam produced in the second step upstream and downstream of the tube furnace respectively. Then, flush with nitrogen at a flow rate of 150 sccm for 10 minutes. Then, heat the tube furnace to 350°C at a heating rate of 2°C / min at a flow rate of 60 sccm and keep it warm for 2 hours. Finally, collect the phosphating substrate and record it as Ce-CoP / NiCoP-NF-2.
[0039] Example 4
[0040] 01. Nickel foam (3 cm × 2 cm) was used as the substrate and ultrasonically cleaned in 3M HCl, acetone and ethanol for 30 minutes, and then the cleaned nickel foam was vacuum dried at 60°C for 12 hours;
[0041] 02. Dissolve 0.6mmol Ni(NO3)2·6H2O, 1.2mmol Co(NO3)2·6H2O, 0.12mmol Ce(NO3)3·6H2O, 12mmol CO(NH2)2 and 6mmol NH4F in 40mL deionized water, stir the solution evenly with a magnetic stirrer, then transfer the mixed solution to a 100mL stainless steel autoclave lined with Teflon, and immerse the clean nickel foam in the reaction solution, keep it at 120℃ for 8 hours, and after the autoclave is naturally cooled to room temperature, take out the nickel foam coated with pink-purple material, then, use distilled water and anhydrous ethanol for ultrasonic cleaning, and then fully dry it in a vacuum drying oven at 60℃;
[0042] 03. 200 mg of triphenylphosphine and the nickel foam produced in the second step were placed upstream and downstream of the tube furnace respectively. Then, nitrogen was flushed at a flow rate of 150 sccm for 10 minutes. Then, the tube furnace was heated to 300°C at a heating rate of 2°C / min at a flow rate of 60 sccm and kept warm for 2 hours. Finally, the phosphating substrate was collected and recorded as Ce-CoP / NiCoP-NF-3.
[0043] Comparative Example 1
[0044] 01. Nickel foam (3 cm × 2 cm) was used as the substrate and ultrasonically cleaned in 3M HCl, acetone and ethanol for 30 minutes, and then the cleaned nickel foam was vacuum dried at 60°C for 12 hours;
[0045] 02. Dissolve 0.6mmol Ni(NO3)2·6H2O, 1.2mmol Co(NO3)2·6H2O, 12mmol CO(NH2)2 and 6mmol NH4F in 40mL deionized water, stir the solution evenly with a magnetic stirrer, then transfer the mixed solution to a 100mL stainless steel autoclave lined with Teflon, and immerse the clean nickel foam in the reaction solution, keep it at 120℃ for 8 hours, and after the autoclave is naturally cooled to room temperature, take out the nickel foam coated with pink-purple material, then, ultrasonically clean it with distilled water and anhydrous ethanol, and then fully dry it in a vacuum drying oven at 60℃;
[0046] 03. Place 200 mg of triphenylphosphine and the nickel foam produced in the second step upstream and downstream of the tube furnace respectively. Then, flush with nitrogen at a flow rate of 150 sccm for 10 minutes. Then, heat the tube furnace to 350°C at a heating rate of 2°C / min at a flow rate of 60 sccm and keep it warm for 2 hours. Finally, collect the phosphating substrate and record it as CoP / NiCoP-NF.
[0047] Comparative Example 2
[0048] 01. Nickel foam (3 cm × 2 cm) was used as the substrate and ultrasonically cleaned in 3M HCl, acetone and ethanol for 30 minutes, and then the cleaned nickel foam was vacuum dried at 60°C for 12 hours;
[0049] 02. Dissolve 0.6mmol Ni(NO3)2·6H2O, 1.2mmol Co(NO3)2·6H2O, 0.12mmol Ce(NO3)3·6H2O, 12mmol CO(NH2)2 and 6mmol NH4F in 40mL deionized water, stir the solution evenly with a magnetic stirrer, then transfer the mixed solution to a 100mL stainless steel autoclave lined with Teflon, and immerse the clean nickel foam in the reaction solution, keep it at 120℃ for 8 hours, and after the autoclave is naturally cooled to room temperature, take out the nickel foam coated with pink-purple material, then use distilled water and anhydrous ethanol ultrasonic cleaning, and then fully dry it in a vacuum drying oven at 60℃ and record it as Ce-NiCo-NF.
[0050] The following table shows the test data of the embodiments and comparative examples:
[0051] sample <![CDATA[HER(10mAcm -2 )vs.RHE]]> Ce-CoP / NiCoP-NF 26mV Ce-CoP / NiCoP-NF-1 78mV Ce-CoP / NiCoP-NF-2 112mV Ce-CoP / NiCoP-NF-3 56mV CoP / NiCoP-NF 133mV Ce-NiCo-NF 180mV
[0052] The present invention provides a method for synthesizing a foamed nickel-based cerium-doped CoP / NiCoP composite nanorod catalyst by an innovative hydrothermal method and a low-temperature phosphating strategy, combining the transition metal phosphide CoP and NiCoP which have high activity in hydrogen production by electrolysis of water, and introducing the rare earth element cerium doping to optimize the electron distribution of the active center of the transition metal phosphide, thereby enhancing the activity and stability of the catalyst.
[0053] In the present invention, the doping of Ce atoms will lead to lattice distortion and a large number of defects on the surface of the phosphide, thereby improving the electron transfer ability and catalytic activity of CoP / NiCoP. At the same time, one or more of erbium, praseodymium and lanthanum can be used to replace Ce atoms.
[0054] Secondly, the interfacial electronic synergy between the CoP / NiCoP heterostructures balances the adsorption binding strength of the intermediates, resulting in fast kinetics and high intrinsic activity;
[0055] Furthermore, urea and NH4F were used as structure-directing agents to construct rod-like nanostructures, which were beneficial for providing abundant active sites and unique open structures during the electrolysis process;
[0056] Finally, the in-situ growth and phosphating method is adopted to achieve a close bond between the catalyst and the substrate, and the use of adhesives is avoided.
[0057] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.
[0058] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing a Ce-CoP / NiCoP-NF catalyst, characterized in that: The following steps are involved: Step 1: Add nickel salt, cobalt salt, cerium salt, ammonium fluoride and urea into deionized water to prepare a mixed solution; Step 2: transferring the mixed solution prepared in the first step into a reactor, and placing the substrate into the reactor for hydrothermal reaction to prepare a nickel-cobalt-cerium composite precursor; Step 3: placing the dried nickel-cobalt-cerium composite precursor and the phosphorus source in a tube furnace and phosphating them under a nitrogen atmosphere to obtain a Ce-CoP / NiCoP-NF catalyst.
2. The method for preparing a Ce-CoP / NiCoP-NF catalyst according to claim 1, characterized in that: The substrate is one of nickel foam, nickel-iron foam, copper foam, nickel mesh and nickel felt.
3. The method for preparing a Ce-CoP / NiCoP-NF catalyst according to claim 1, characterized in that: The phosphorus source is one of triphenylphosphine, sodium phosphite and sodium hypophosphite.
4. The method for preparing a Ce-CoP / NiCoP-NF catalyst according to claim 1, characterized in that: The nickel salt, cobalt salt and cerium salt are nitrates, sulfates or chlorides containing nickel, cobalt and cerium.
5. The method for preparing a Ce-CoP / NiCoP-NF catalyst according to claim 1, characterized in that: The nickel salt, cobalt salt and cerium salt are Ni(NO3)2·6H2O, Co(NO3)2·6H2O and Ce(NO3)3·6H2O respectively.
6. The method for preparing a Ce-CoP / NiCoP-NF catalyst according to claim 1, characterized in that: The molar ratio of the nickel salt, the cobalt salt, the cerium salt, the ammonium fluoride and the urea is (0.05-0.2):(0.1-0.25):(0.01-0.03):2:
1.
7. The method for preparing a Ce-CoP / NiCoP-NF catalyst according to claim 1, characterized in that: The temperature of the hydrothermal reaction is 80-150° C. and the time is 6-8 hours.
8. The method for preparing a Ce-CoP / NiCoP-NF catalyst according to claim 1, characterized in that: During phosphating, the tube furnace is heated to 250-400°C at a heating rate of 2-5°C / min and kept warm for 0.5-4 hours.
9. The method for preparing a Ce-CoP / NiCoP-NF catalyst according to claim 1, characterized in that: The following steps are involved: Step 1: Using nickel foam as a substrate, ultrasonic cleaning was performed in 3M HCl, acetone and ethanol for 30 minutes, and then the cleaned nickel foam was vacuum dried at 60°C for 12 hours; Step 2: Dissolve 0.6mmol Ni(NO3)2·6H2O, 1.2mmol Co(NO3)2·6H2O, 0.12mmol Ce(NO3)3·6H2O, 12mmol CO(NH2)2 and 6mmol NH4F in 40mL deionized water, and stir the solution evenly using a magnetic stirrer; then transfer the mixed solution to a 100mL stainless steel autoclave lined with Teflon, and immerse the nickel foam cleaned in the first step into the reaction solution, keep it at 120°C for 8 hours, and after the autoclave is naturally cooled to room temperature, take out the nickel foam coated with the pink-purple material, then, use distilled water and anhydrous ethanol for ultrasonic cleaning, and then fully dry it in a vacuum drying oven at 60°C; Step 3: Place 200 mg of triphenylphosphine and the nickel foam produced in the second step at the upstream and downstream of the tube furnace respectively, then flush with nitrogen at a flow rate of 150 sccm for 10 minutes, and then heat the tube furnace to 350°C at a heating rate of 2°C / min at a flow rate of 60 sccm, and keep it warm for 2 hours. Finally, collect the phosphating substrate to obtain the Ce-CoP / NiCoP-NF catalyst.