Nickel-aluminum quantum dot modified polyacid electrocatalyst as well as preparation method and application thereof
By preparing a polyacid electrocatalyst modified with nickel-aluminum quantum dot, the problem of poor catalytic activity of precious metal platinum in an alkaline environment is solved, and low-cost and efficient alkaline water electrolysis is achieved, which is suitable for alkaline seawater electrolysis, improving the efficiency and stability of hydrogen production by electrolyzing water.
Patent Information
- Application Number
- CN202510618431.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-14
- Publication Date
- 2025-08-08
AI Technical Summary
In the prior art, precious metal platinum has problems such as expensive and limited reserves in hydrogen evolution reaction, and has poor catalytic activity in alkaline environments, resulting in low efficiency of alkaline water electrolysis and high overpotential making it difficult to achieve large-scale application; at the same time, alkaline seawater electrolysis faces the problems of high catalyst cost, low activity and poor stability, which affects the effective utilization of seawater resources.
A polyacid electrocatalyst modified with nickel-aluminum quantum dots was prepared on the metal mesh matrix by cyclic voltammetry electrodeposition, adjusting the electronic structure and increasing the active site, and combining polyacid anions to attach during the electrodeposition process to enhance catalytic activity.
It reduces the overpotential of the hydrogen evolution reaction, improves the electrolytic efficiency and stability, and can show excellent catalytic performance in an alkaline environment. It is suitable for alkaline seawater electrolysis, reduces costs and improves the efficiency of hydrogen production by electrolyzing water.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of electrocatalysts, and in particular to a nickel-aluminum quantum dot-modified polyacid electrocatalyst and a preparation method and application thereof. Background Art
[0002] With the surge in global demand for clean energy, hydrogen's zero-pollution and high energy density have made it an ideal choice for the green energy sector. Currently, China's hydrogen energy industry is experiencing a golden period of rapid development. It is not only a key force in transforming its energy structure, but also faces unprecedented development opportunities driven by policy support, technological advancements, and market potential. Among the many hydrogen production technologies, water electrolysis stands out for its environmental advantages, making it a key development direction for future green hydrogen production.
[0003] The hydrogen evolution reaction (HER) is a key electrochemical reaction in the electrolysis of water to produce hydrogen. During water electrolysis, water molecules gain electrons on the electrode surface, undergoing a reduction reaction and ultimately producing hydrogen. To improve the efficiency of the HER, it is often necessary to select suitable electrocatalytic materials, such as the precious metal platinum and ruthenium. These electrocatalysts can reduce the reaction's overpotential and improve the efficiency of water electrolysis.
[0004] However, the inventors believe that the following technical problems still exist in the hydrogen evolution reaction:
[0005] Platinum can significantly reduce the overpotential of the hydrogen evolution reaction and improve the reaction efficiency, but platinum is expensive and its reserves are very limited, which makes the widespread use of platinum face serious economic problems. Therefore, it is of great significance to develop electrocatalysts with lower costs, which can replace platinum or study low platinum loading. In addition, platinum has excellent hydrogen evolution reaction performance in acidic environments, but its catalytic activity in alkaline solutions is poor, and its activity in acidic environments is as low as about 2 to 3 orders of magnitude lower. This problem greatly limits the application of platinum catalysts in alkaline water electrolysis. In order to overcome this problem, it is urgent to develop new catalyst materials to achieve higher catalytic efficiency and reduce overpotential in alkaline environments.
[0006] Alkaline water electrolysis technology has therefore attracted increasing attention. However, due to the slow kinetics of the hydrogen evolution reaction, a large overpotential is typically required for effective operation. In practical applications, this overpotential not only increases energy consumption but also affects the efficiency of the entire electrolysis process. Therefore, developing lower-cost alternatives to platinum or researching low-platinum-loading electrocatalysts to reduce overpotential and improve electrolysis efficiency is key to achieving large-scale application of alkaline water electrolysis.
[0007] In recent years, alkaline seawater electrolysis has gradually entered the research field as a promising technology. By directly electrolyzing alkaline seawater, seawater resources can be effectively utilized. However, despite the huge potential of alkaline seawater electrolysis, it still faces multiple challenges such as high catalyst cost, low catalytic activity and poor stability. The high concentration of salt and impurities in seawater not only has a negative impact on the stability of the catalyst but also interferes with the selection of the catalyst. This requires that the catalyst must not only have high activity and clear selectivity, but also must have good anti-pollution and corrosion resistance. These issues are the key to achieving low-cost, efficient and stable catalysis in seawater electrolysis, and are also the key to its commercial application.
[0008] Therefore, in order to solve the above problems, the present invention designs and develops a new preparation method for preparing nickel-aluminum quantum dot modified polyacid electrocatalyst, which can effectively improve the above problems.
[0009] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention
[0010] In response to the above technical problems, the embodiments of the present invention provide a nickel-aluminum quantum dot modified polyacid electrocatalyst and its preparation method and application to solve the problems raised in the above background technology.
[0011] A method for preparing a nickel-aluminum quantum dot modified multi-acid seawater electrolysis electrocatalyst comprises the following steps:
[0012] Weigh the raw materials for preparing the electrolyte solution; including:
[0013] aluminum salts, nickel salts, polyacids, and sodium citrate;
[0014] The raw materials were mixed evenly with deionized water, and the pH was adjusted to 9.5 to obtain the target electrolyte solution;
[0015] The metal mesh substrate was used as the working electrode, the saturated calomel electrode was used as the reference electrode, and the graphite electrode was used as the auxiliary electrode.
[0016] Nickel-aluminum quantum dot-modified polyacid electrocatalysts were prepared by cyclic voltammetry electrodeposition on a metal mesh substrate.
[0017] Preferably, the aluminum salt is aluminum sulfate 18hydrate; the nickel salt is nickel sulfate hexahydrate; and the precursor substance of the polyacid is ammonium molybdate tetrahydrate.
[0018] Preferably, the current density used in the electrodeposition is -10 mA / cm 2 -100mA / cm 2 .
[0019] Preferably, the electrodeposition time used in the electrodeposition is 300 s.
[0020] Preferably, the material of the metal mesh substrate is one or more of titanium mesh, copper mesh and nickel mesh.
[0021] Preferably, the polyacid is one or more of Anderson-type, Keggin-type, Dawson-type, and Weakly-type polyacids.
[0022] A nickel-aluminum quantum dot modified polyacid electrocatalyst prepared according to the above preparation method, wherein the electrocatalyst of the present invention is named POM@NiAl.
[0023] Preferably, the molar ratio of Ni, Mo and Al in the electrocatalyst is 15:5:5.
[0024] Preferably, the electrocatalyst is at 10 mA / cm 2 The overpotential at a current density of 22.7 mV is obtained; the Tafel slope in alkaline solution is 70.42 mVdec. -1 The electrocatalyst can be used in alkaline electrolyte environment and alkaline simulated seawater at -100mA / cm 2 The device can run stably for at least 200h at a current density of
[0025] Application of a nickel-aluminum quantum dot-modified polyacid electrocatalyst prepared according to the above-mentioned preparation method in a hydrogen evolution reaction.
[0026] The nickel-aluminum quantum dot modified polyacid electrocatalyst and its preparation method and application provided in the embodiments of the present invention have the following beneficial effects:
[0027] (1) The present invention prepares Al-doped POM@Ni electrocatalyst. Al doping regulates the electronic structure of Ni and Mo and exhibits a synergistic catalytic effect.
[0028] (2) The synergistic effect between Ni, Mo, and Al elements makes the surface morphology rough, resulting in the distribution of numerous particles on the nickel-aluminum quantum dot-modified polyacid electrocatalyst, which increases the number of active sites and the electrochemically active surface area.
[0029] (3) Nickel-aluminum quantum dot-modified polyacid electrocatalysts showed good activity in hydrogen evolution reaction with a low initial reaction potential.
[0030] (4) The structure of the electrocatalyst effectively reduces the interfacial resistance and increases the charge transfer rate.
[0031] (5) The prepared nickel-aluminum quantum dot-modified polyacid electrocatalyst has good hydrogen evolution reaction performance and electrochemical stability in alkaline and alkaline seawater.
[0032] (6) During the electrodeposition process, the anions of polyacids (such as molybdate ions) in the electrolyte solution will attach to or embed into the formed nickel-aluminum quantum dot-modified structure, which can enhance the catalytic activity and regulate the surface properties, thereby improving the performance of the electrocatalyst.
[0033] (7) The synthesis process of this method is simple, efficient, and controllable, and can be synthesized in large quantities, providing great possibilities for actual production. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Figure 1 SEM image of POM@NiAl electrocatalyst;
[0035] Figure 2 EDS image of POM@NiAl electrocatalyst;
[0036] Figure 3 The LSV curve test results of different electrocatalysts;
[0037] Figure 4 The experimental results of hydrogen evolution overpotential comparison of different electrocatalysts are shown;
[0038] Figure 5 The experimental results of CV cycle electrochemical stability test of POM@NiAl electrocatalyst;
[0039] Figure 6 The experimental results of long-term stability test of POM@NiAl electrocatalyst in 1MKOH electrolyte;
[0040] Figure 7 The experimental results of HER activity test of different electrocatalysts in alkaline simulated seawater;
[0041] Figure 8 The overpotential test results of different electrocatalysts in alkaline simulated seawater;
[0042] Figure 9 The experimental results of long-term stability test of POM@NiAl electrocatalyst in alkaline simulated seawater;
[0043] Figure 10 The experimental results of HER activity test of different electrocatalysts in alkaline seawater;
[0044] Figure 11 The overpotential test results of different electrocatalysts in alkaline seawater;
[0045] Figure 12This is a long-term stability test experiment of POM@NiAl electrocatalyst in alkaline seawater. DETAILED DESCRIPTION
[0046] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.
[0047] In response to the above technical problems, the embodiments of the present invention provide a nickel-aluminum quantum dot modified polyacid electrocatalyst and its preparation method and application to solve the problems raised in the above background technology.
[0048] Experiment 1: SEM and EDS characterization of POM@NiAl electrocatalyst
[0049] Preparation of POM@NiAl electrocatalyst includes the following steps:
[0050] Step 1: The composition of the electrolyte solution: 1.613 g of aluminum sulfate 18hydrate, 3.817 g of nickel sulfate hexahydrate, 0.855 g of ammonium molybdate tetrahydrate (a precursor of polyacid), and 3.400 g of sodium citrate are mixed and dissolved in 60 ml of deionized water; sodium carbonate is slowly added to adjust the pH to 9.5 to obtain an electrolyte solution.
[0051] Step 2: Cut the Ti mesh into rectangles and use it as the working electrode. The reference electrode is a saturated calomel electrode and the auxiliary electrode is a graphite electrode to form a three-electrode system for electrodeposition.
[0052] The prepared POM@NiAl electrocatalyst was subjected to SEM and EDS characterization experimental tests; it should be noted that the POM@NiAl electrocatalysts used in the following other experiments were all prepared using the raw material composition and experimental steps in Experiment 1.
[0053] Figure 1 This is an SEM image of the POM@NiAl electrocatalyst. The surface of the POM@NiAl electrocatalyst is covered with a uniform and rough layer of material, with numerous small particles attached, and no obvious cracks. This indicates that the covering layer has excellent bonding with the titanium mesh matrix, which enhances the charge transfer efficiency and thus improves the hydrogen evolution performance of the electrode.
[0054] Figure 2This is an EDS image of the POM@NiAl electrocatalyst. Analysis shows that the sample is mainly composed of five elements: nickel (Ni), molybdenum (Mo), aluminum (Al), oxygen (O) and titanium (Ti). Among them, the proportion of titanium has decreased, while the distribution of nickel, molybdenum and aluminum elements appears to be relatively even. In addition, oxygen elements are mainly attached to the surface of the titanium mesh in trace form. It was observed through the element mapping that when the molar ratio of Ni / Mo / Al reaches 15:5:5, nickel, molybdenum and aluminum can be effectively electrodeposited on the titanium mesh, and the deposition effect is good.
[0055] Experiment 2: LSV curve test of different electrocatalysts and comparison of hydrogen evolution overpotential
[0056] Figure 3 The electrodeposition current density is -100mA / cm 2 , LSV curves of POM@Al, NiAl, POM@Ni, POM@NiAl electrocatalysts and Pt / C electrode prepared at an electrodeposition time of 300 s; wherein the parameters of the electrodeposition conditions in the above electrocatalysts are the same.
[0057] Figure 4 As shown, at -10mA / cm 2 At a current density of 1.5 wt %, the hydrogen evolution overpotentials of these different electrocatalysts reached 314 mV, 236.7 mV, 44.8 mV, 22.7 mV and 35.5 mV, respectively.
[0058] Experiments have shown that, compared to POM@Al electrocatalysts, POM@NiAl electrocatalysts exhibit lower overpotentials in the hydrogen evolution reaction, demonstrating excellent activity, a low initial reaction potential, and the ability to withstand higher current outputs. By introducing elements such as nickel, molybdenum, and aluminum, the density and surface area of electrochemically active sites are significantly increased, while the electrode microstructure is optimized, effectively reducing interfacial resistance and achieving higher charge transfer efficiency.
[0059] Experiment 3: CV cycle electrochemical stability test of POM@NiAl electrocatalyst
[0060] Figure 5 The LSV curves of POM@NiAl electrocatalyst before and after 1000 CV cycles of electrochemical stability test are shown. 2 The hydrogen evolution overpotential of the POM@NiAl electrocatalyst after the stability test was 40.6 mV, which was lower than 22.7 mV before the stability test. However, the overall trend before and after the stability test was basically the same, indicating that the POM@NiAl electrocatalyst still had good hydrogen evolution reaction performance and good electrochemical stability.
[0061] Experiment 4: Long-term stability test of POM@NiAl electrocatalyst in 1MKOH electrolyte
[0062] Figure 6 The figure shows the changes of POM@NiAl electrocatalyst in 1M KOH electrolyte environment for 200 hours. During the 200-hour hydrogen evolution reaction, the current density of the electrocatalyst was maintained at about -100mA / cm 2 , and its decay rate is low, which highlights the excellent stability characteristics of POM@NiAl electrocatalyst in electrochemistry.
[0063] Experiment 5: HER activity and overpotential testing of different electrocatalysts in alkaline simulated seawater
[0064] Figure 7 In an alkaline simulated seawater environment (1MKOH+0.5MNaCl), when the electrodeposition current density is -100mA / cm 2 , LSV curves of POM@Al, NiAl, POM@Ni, POM@NiAl electrocatalysts and Pt / C electrode prepared at electrodeposition time of 300s.
[0065] Figure 7 The results show that POM@NiAl electrocatalyst has the highest HER activity and 2 and 100mA / cm 2 At a current density of 1.5 and 2.5, only 48mV and 140mV of low overpotential are required, respectively, which is better than POM@Al, NiAl, and POM@Ni electrocatalysts. Figure 8 The current density is -10mA / cm 2 and -100mA / cm 2 of hydrogen evolution overpotential.
[0066] Experiment 6: Long-term stability test of POM@NiAl electrocatalyst in alkaline simulated seawater
[0067] Figure 9 The figure shows the changes of the POM@NiAl electrocatalyst in alkaline simulated seawater (1M KOH + 0.5M NaCl) for 200 hours. During the 200-hour hydrogen evolution reaction, the current density of the electrocatalyst was maintained at approximately -100 mA / cm 2 , and its decay rate is low, which highlights the excellent stability characteristics of POM@NiAl electrocatalyst in electrochemistry.
[0068] Experiment 7: HER activity and overpotential test of different electrocatalysts in alkaline seawater
[0069] Figure 10In alkaline seawater environment, when the electrodeposition current density is -100mA / cm 2 , LSV curves of POM@Al, NiAl, POM@Ni, POM@NiAl electrocatalysts and Pt / C electrode prepared at electrodeposition time of 300s.
[0070] Figure 10 The results show that POM@NiAl electrocatalyst has the highest HER activity and 2 and -100mA / cm 2 At a current density of 1.5 and 2.5 Å, only 55 mV and 155 mV of low overpotential are required, respectively, which is better than POM@Al, NiAl, and POM@Ni electrocatalysts. Figure 11 The current density is 10 mA / cm 2 and 100mA / cm 2 of hydrogen evolution overpotential.
[0071] Experiment 8: Long-term stability test of POM@NiAl electrocatalyst in alkaline seawater
[0072] Figure 12 Under constant voltage, the POM@NiAl electrocatalyst can maintain -100 mA / cm in alkaline seawater solution for 200 h. 2 The current has basically no obvious attenuation, which highlights the excellent stability characteristics of POM@NiAl electrocatalyst in electrochemistry.
[0073] In summary, the POM@NiAl electrocatalyst prepared in this invention shows excellent HER activity in 1MKOH solution, which is comparable to that of commercial 20% Pt / C electrocatalyst. 2 Its overpotential is only 22.7 mV at a current density of , which reflects its good electrocatalytic activity; the Tafel slope in alkaline solution is 70.42 mVdec-1, indicating that the electrocatalyst of the present invention has good performance.
[0074] In addition, the POM@NiAl electrocatalyst showed good stability and could 2 The POM@NiAl electrocatalyst we prepared has excellent HER performance and low overpotential in alkaline simulated seawater (1MKOH+0.5MNaCl) and alkaline seawater environments, and can operate stably at -100mA / cm 2 It can operate stably for 200 h at a current density of 1.5 wt % with basically no obvious attenuation, which highlights the excellent stability characteristics of POM@NiAl electrocatalyst in electrochemistry and shows broad application prospects in H2 production.
[0075] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.
Claims
1. A method for preparing a nickel-aluminum quantum dot modified multi-acid seawater electrolysis electrocatalyst, characterized in that: The following steps are involved: Weigh the raw materials for preparing the electrolyte solution; including: Aluminum salts, nickel salts, polyacids, and sodium citrate; The raw materials were mixed evenly with deionized water, and the pH was adjusted to 9.5 to obtain the target electrolyte solution; The metal mesh substrate was used as the working electrode, the saturated calomel electrode was used as the reference electrode, and the graphite electrode was used as the auxiliary electrode. Nickel-aluminum quantum dot-modified polyacid electrocatalysts were prepared by cyclic voltammetry electrodeposition on a metal mesh substrate.
2. The method for preparing the nickel-aluminum quantum dot modified multi-acid seawater electrolysis electrocatalyst according to claim 1, characterized in that: The aluminum salt is aluminum sulfate 18hydrate; the nickel salt is nickel sulfate hexahydrate; and the precursor substance of the polyacid is ammonium molybdate tetrahydrate.
3. The method for preparing the nickel-aluminum quantum dot modified multi-acid seawater electrolysis electrocatalyst according to claim 1, characterized in that: The current density used in the electrodeposition was -10 mA / cm 2 -100mA / cm 2 .
4. The method for preparing the nickel-aluminum quantum dot modified multi-acid seawater electrolysis electrocatalyst according to claim 1, characterized in that: The electrodeposition time used in the electrodeposition was 300 s.
5. The method for preparing the nickel-aluminum quantum dot modified multi-acid seawater electrolysis electrocatalyst according to claim 1, characterized in that: The material of the metal mesh substrate is one or more of titanium mesh, copper mesh and nickel mesh.
6. The method for preparing the nickel-aluminum quantum dot modified multi-acid seawater electrolysis electrocatalyst according to claim 1, characterized in that: The polyacid is one or more of Anderson-type, Keggin-type, Dawson-type, and Weakly-type polyacids.
7. A nickel-aluminum quantum dot-modified polyacid electrocatalyst prepared according to the preparation method according to any one of claims 1 to 6.
8. The nickel-aluminum quantum dot modified polyacid electrocatalyst according to claim 7, characterized in that The molar ratio of Ni, Mo, and Al in the electrocatalyst is 15:5:
5.
9. The nickel-aluminum quantum dot modified polyacid electrocatalyst according to claim 7, characterized in that Electrocatalyst at 10 mA / cm 2 The overpotential at the current density is 22.7mV; The Tafel slope in alkaline solution is 70.42 mVdec -1 The electrocatalyst can be used in alkaline electrolyte environment and alkaline simulated seawater at -100mA / cm 2 The device can run stably for at least 200h at a current density of 10. Use of a nickel-aluminum quantum dot-modified polyacid electrocatalyst prepared according to the preparation method according to any one of claims 1 to 6 in a hydrogen evolution reaction.