Preparation method and application of ultrafast magnetic field-induced quenching synthesis monatomic catalyst

Abstract

This invention discloses a method for preparing and applying an ultrafast magnetic field-induced quenching synthesis of single-atom catalysts. Precursors such as nickel nitrate, nickel chloride, nickel sulfate, and nickel acetate are dispersed in ethanol to obtain a precursor dispersion. The surface area of ​​the catalyst is 1–100 cm². 2 The current collector is heated at 600-900℃ for 3-8 seconds using a high-frequency induction heater, then rapidly quenched in a precursor dispersion at room temperature, and cleaned to obtain a self-supported single-atom catalyst. The single atoms are supported on a graphene layer formed by the rapid decomposition and carbonization of ethanol, with a loading of 1-10%. This self-supported catalyst can be used directly as an electrode without a binder, exhibiting high electrocatalytic activity and long-term stability, making it suitable for large-scale water electrolysis for hydrogen production. This invention enables the rapid, batch preparation of single-atom catalysts within seconds, with a simple process, low cost, and ease of large-scale production.

Description

Technical Field

[0001] This invention belongs to the field of water electrolysis catalyst technology, and specifically relates to a method for preparing and applying an ultrafast magnetic field-induced quenching synthesis of single-atom catalysts. Background Technology

[0002] Improving the atom economy of chemical reactions and ensuring the maximum utilization of rare catalytic materials are core objectives of sustainable chemistry. Single-atom catalysts (SACs), by combining atomically dispersed metal centers with customizable coordination environments, have shown the potential to achieve these two goals in the field of energy catalysis. The catalytic performance of SACs is determined by the local coordination structure of the active site, which in turn depends on the synthetic route. Therefore, the practical application of SACs is inseparable from their preparation methods, highlighting the importance of developing simple and universal synthetic strategies to facilitate their practical application.

[0003] Researchers have developed various methods for synthesizing SACs, including atomic layer deposition, high-temperature pyrolysis, wet chemical methods, and coordination assembly strategies. However, these synthetic routes often involve complex preparation processes, requiring pre-prepared precursors and multiple post-processing steps, or relying on specialized and expensive equipment. More importantly, the synthesis of most SACs (especially carbon-based SACs) heavily depends on prolonged high-temperature calcination to achieve the carbonization process, which is both time-consuming and energy-intensive. Therefore, developing low-cost, simple, and ultrafast SAC synthesis strategies is crucial for advancing basic research and industrial applications. Summary of the Invention

[0004] To overcome the problems of complex and expensive existing single-atom preparation processes, the present invention aims to provide a method and application for the preparation of single-atom catalysts via ultrafast magnetic field-induced quenching. The goal is to successfully construct a series of single-atom catalysts (M=Ni, Fe, Co, Ir, Ru, Pt, etc.) within seconds through magnetic field-induced quenching, and achieve excellent water electrolysis catalytic activity, providing a strategy for the rapid and scalable production of advanced energy functional materials.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In one aspect, a method for preparing a single-atom catalyst by ultrafast magnetic field-induced quenching synthesis is provided, comprising the following steps: Step 1: Disperse the precursor in ethanol to obtain a precursor dispersion. Step 2, use a high-frequency induction heater to heat the current collector (1~100 cm). 2 The annealed current collector is heated and then immersed in the precursor dispersion at room temperature for rapid quenching, followed by washing to obtain a self-supporting single-atom catalyst.

[0006] In one embodiment, the precursor is one or more of a single metal nitrate, chloride, sulfate, and acetate, wherein the single metal is nickel, cobalt, iron, iridium, ruthenium, or platinum, etc. In the experiment, the mass-to-volume ratio of precursor to ethanol can be set to (2~8) g: 10~30 mL, which satisfies the dispersion requirements, saves ethanol, and meets the need for rapid preparation. This allows for the rapid, batch preparation of single-atom catalysts within seconds, with a simple process, low cost, and ease of large-scale production.

[0007] In one embodiment, the current collector is one or more of nickel foam, iron foam, and copper foam. The cleaning includes sequential deionized water cleaning and ethanol cleaning; the deionized water cleaning is performed 2 to 4 times, and the ethanol cleaning is performed 2 to 4 times.

[0008] Preferably, the precursor is nickel nitrate.

[0009] Preferably, the concentration of the precursor dispersion is 0.1~1 g / mL, more preferably 0.2~0.6 g / mL.

[0010] Preferably, the current collector is heated using a high-frequency induction heater at a temperature of 500-1000°C for a duration of [missing information]. 10 s, for example, 1~10 s; preferably, the heating temperature is 600~900℃ and the heating time is 3~8 s.

[0011] Preferably, the frequency of the high-frequency induction heater is 30-100 kHz and the current is 1-50 A.

[0012] The high-frequency induction heating process of this invention forms a thin layer of metal oxide on the surface of the current collector, providing an active substrate for subsequent single-atom anchoring.

[0013] In a second aspect, the present invention provides an ultrafast magnetic field-induced quenching synthesis of a single-atom catalyst, obtained by the preparation method of the ultrafast magnetic field-induced quenching synthesis of a single-atom catalyst described in the first aspect. The single atoms are supported on a graphene layer carbonized by the rapid decomposition of ethanol, and the single-atom loading is 1-10% by weight; if the loading is too high, aggregation is likely to occur.

[0014] In a third aspect, the present invention provides the application of the ultrafast magnetic field-induced quenching synthesis of single-atom catalysts described in the second aspect as electrodes. These catalysts can be used directly as electrodes without the need for binders and have high electrocatalytic activity and long-term stability, making them suitable for large-scale water electrolysis for hydrogen production.

[0015] This self-supporting catalyst can be used directly as an electrode without the need for a binder. In one embodiment, the application specifically includes the following steps: Step (1): Cut 1~4 cm 2 (Typical example: 1 cm) 2 Ultrafast magnetic field-induced quenching synthesis of single-atom catalysts; Step (2): The oxygen evolution reaction was tested using a three-electrode system, with the single-atom catalyst as the working electrode, a platinum sheet as the counter electrode, and silver / silver chloride as the reference electrode. Step (3): In potassium hydroxide electrolyte (typically 1 M), obtain linear sweep voltammetry curves at a scan rate of 5 mV / s to evaluate the oxygen evolution reaction performance. The range of the linear sweep voltammetry curves is 1.1 to 1.7 V relative to the reversible hydrogen electrode. Step (4): Electrolyze water using an anion exchange membrane hydroelectric cell, with the single-atom catalyst as the anode and platinum-modified nickel-iron layered hydroxide as the cathode. Both the cathode and anode electrolytes are potassium hydroxide solutions, and the cathode and anode chambers are separated by an anion exchange membrane. Step (5): Keep the cathode / anode electrolyte circulating in the electrolytic cell at a flow rate of 10~30 mL / min, and obtain linear scanning voltammetric curves at a scanning rate of 5 mV / s within a voltage range of 1~2.2 V to evaluate the water electrolysis performance.

[0016] The test aims to reasonably and accurately evaluate the performance of the ultrafast magnetic field-induced quenching synthesis single-atom catalyst applied to water electrolysis.

[0017] Compared with the prior art, the beneficial effects of the present invention are: (1) Due to the synergistic effect of the instantaneous high-temperature field of high-frequency induction heating and ethanol quenching, this invention can efficiently synthesize single-atom catalysts within seconds. This method is applicable to a variety of metal types, demonstrating excellent versatility. The synthesis process used in this invention is simple and fast, time-saving, and highly safe, facilitating process monitoring and large-scale preparation. It significantly reduces production costs and process complexity, possessing good industrialization potential.

[0018] (2) The catalyst prepared in this invention has a self-supporting structure, with single-atom active sites directly loaded on the graphene layer formed on the surface of the current collector, without the need for binders or additional substrates. This structure greatly enhances the mechanical stability and interfacial bonding force of the catalyst in electrochemical reactions, effectively inhibits the shedding of active components, and thus significantly extends the catalyst lifetime. At the same time, the self-supporting form can be used directly as an electrode, eliminating the need for traditional coating, tableting and other post-processing steps, providing a key structural basis for the ultrafast batch preparation and large-scale production of single-atom catalysts, and further improving the technical and economic efficiency.

[0019] (3) Because the single atoms are directly anchored on the graphene layer generated in situ by the current collector, the ultrafast magnetic field-induced quenching synthesis single-atom catalyst prepared in this invention has a large electrochemical active area, improving mass transfer. Due to the flexibility of its structure and composition, its electronic structure is optimized, enhancing the adsorption of single atoms with OOH*. It exhibits excellent oxygen evolution performance and anion exchange membrane water electrolyzer performance in alkaline media, and can maintain stable performance under high current for a long time, showing good application prospects in the field of electrocatalysis. Attached Figure Description

[0020] Figure 1 This is a flowchart of a method for preparing single-atom catalysts by ultrafast magnetic field-induced quenching.

[0021] Figure 2 Ni-SA / G-FeO prepared in Example 1 x Aberration-corrected electron microscopy characterization of the catalyst -1.

[0022] Figure 3 Ni-SA / G-FeO prepared in Example 1 x Aberration-corrected electron microscopy characterization of the catalyst -1.

[0023] Figure 4 Ni-SA / G-FeO prepared in Example 1 x Aberration-corrected electron microscopy characterization of the catalyst -1.

[0024] Figure 5 Ni-SA / G-FeO prepared in Example 1 x -1 Catalyst and G-FeO prepared in Comparative Example 1 x X-ray photoelectron spectrum.

[0025] Figure 6 Ni-SA / G-FeO prepared in Example 1 x -1 Catalyst, Ni-SA / FeO prepared in Comparative Example 1 x G-FeO prepared in Comparative Example 2 x Linear voltammetric scan curve of oxygen evolution reaction with catalyst.

[0026] Figure 7 Ni-SA / G-FeO prepared in Example 1 x -1 Catalyst three-electrode stability diagram.

[0027] Figure 8 Ni-SA / G-FeO prepared in Example 1 x -1 Catalyst, Co-SA / G-FeO prepared in Example 2 x Catalyst, Fe-SA / G-FeO prepared in Example 3x Catalyst, Ir-SA / G-FeO prepared in Example 1 x Catalyst and Ru-SA / G-FeO prepared in Example 1 x Linear voltammetric scan curve of oxygen evolution reaction with catalyst.

[0028] Figure 9 Ni-SA / G-FeO prepared in Example 1 x -1 Stability diagram of a catalyst-based alkaline anion exchange membrane water electrolyzer.

[0029] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings and examples.

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the embodiments described herein are only a part of the embodiments of this invention, used to explain the invention, and are not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other. Based on the embodiments of this invention, all other embodiments obtained by other researchers in the art without creative effort are within the protection scope of this invention.

[0031] Unless otherwise specified, all experimental materials and reagents used in the following examples are commercially available.

[0032] Please refer to Figure 1 As shown, the first aspect of this invention proposes a method for preparing a single-atom catalyst through ultrafast magnetic field-induced quenching synthesis, comprising the following steps: Step 1: Add 10-30 mL of ethanol to a beaker, add 2-8 g of precursor salt to the ethanol solution, and stir until completely dissolved.

[0033] Preferably, in this step, the precursor salt is one or more of nickel nitrate, nickel chloride, nickel sulfate, and nickel acetate; more preferably, the precursor salt is nickel nitrate.

[0034] The current collector used in this invention can be one or more of foamed nickel, foamed iron, and foamed copper. Its surface can be ultrasonically cleaned and dried for later use.

[0035] Step 2: The current collector is heated for a certain time using a high-frequency induction heater, and then the annealed current collector is immersed in the precursor dispersion at room temperature for rapid quenching. After cleaning, a self-supporting single-atom catalyst is obtained.

[0036] In this step, the magnetic field-assisted heating rate reaches 100-300℃ / s, which is much higher than that of ordinary resistance heating. After rapid heating, an oxidation reaction occurs on the surface of the current collector to form a thin oxide layer. Secondly, when the hot current collector is immersed in the ethanol solution, the temperature drops sharply, causing the ethanol to decompose and carbonize rapidly, while a graphene layer is deposited on the surface of the current collector. At the same time, the metal species in the precursor ethanol solution are anchored by the formed graphene, forming atomically dispersed metal sites.

[0037] Preferably, in this step, the heating temperature is 600~900℃ and the heating time is 3~8 s; more preferably, the heating temperature is 700℃ and the heating time is 5 s.

[0038] The following are some specific embodiments of the present invention.

[0039] Example 1 This embodiment provides a method for preparing an ultrafast magnetic field-induced quenching synthesis nickel single-atom catalyst, comprising the following steps: Step 1: Add 20 mL of ethanol to a beaker, and add 4 g of nickel nitrate to the ethanol solution. Stir until completely dissolved.

[0040] Step 2: The foamed iron was ultrasonically washed in 3M hydrochloric acid, acetone, ethanol and deionized water for 15 min in sequence, and the cleaned current collector was dried at 60℃ for 2 h.

[0041] Step 3: The cleaned foamed iron was heated at 700℃ for 5 seconds using a high-frequency induction heater. Then, the annealed foamed iron was rapidly quenched by immersing it in an ethanol solution of nickel nitrate at room temperature. After cleaning, a self-supported nickel single-atom catalyst (named Ni-SA / G-FeO) was obtained. x -1).

[0042] In some other embodiments, methods for preparing ultrafast magnetic field-induced quenching synthesis nickel single-atom catalysts are provided, with the remaining operation steps being consistent with those in Example 1, as detailed below. Example 2: This embodiment provides a method for preparing an ultrafast magnetic field-induced quenching synthesis nickel single-atom catalyst, comprising the following steps: 2 g of cobalt nitrate was dispersed in 30 mL of ethanol solution, followed by immersion of iron foam heated at 600 °C for 3 s. After washing, a self-supported cobalt single-atom catalyst (named Ni-SA / G-FeO) was obtained. x -2).

[0043] Example 3: This embodiment provides a method for preparing an ultrafast magnetic field-induced quenching synthesis nickel single-atom catalyst, comprising the following steps: 8 g of nickel nitrate was dispersed in 10 mL of ethanol solution, followed by immersion of iron foam heated at 900 °C for 8 s. After washing, a self-supported cobalt single-atom catalyst (named Ni-SA / G-FeO) was obtained. x -3).

[0044] In some other embodiments, a method for preparing a nickel single-atom catalyst synthesized by ultrafast magnetic field-induced quenching is provided, in which nickel salts are replaced with cobalt, iron, iridium, ruthenium and platinum salts, and the remaining operation steps are the same as in Example 1, as follows.

[0045] Example 4: This embodiment provides a method for preparing a cobalt single-atom catalyst through ultrafast magnetic field-induced quenching synthesis, comprising the following steps: 4 g of cobalt nitrate was dispersed in 20 mL of ethanol solution, followed by immersion of iron foam heated at 700 °C for 5 s. After washing, a self-supported cobalt single-atom catalyst (named Co-SA / G-FeO) was obtained. x ).

[0046] Example 5: This embodiment provides a method for preparing an ultrafast magnetic field-induced quenching synthesis of iron single-atom catalysts, comprising the following steps: 4 g of ferric nitrate was dispersed in 20 mL of ethanol solution, followed by immersion of iron foam heated at 700 °C for 5 s. After washing, a self-supported iron single-atom catalyst (named Fe-SA / G-FeO) was obtained. x ).

[0047] Example 6: This embodiment provides a method for preparing an iridium single-atom catalyst by ultrafast magnetic field-induced quenching synthesis, comprising the following steps: 4 g of iridium acetylacetone was dispersed in 20 mL of ethanol solution, followed by immersion of iron foam heated at 700 °C for 5 s. After washing, a self-supported iridium single-atom catalyst (named Ir-SA / G-FeO) was obtained. x ).

[0048] Example 7: This embodiment provides a method for preparing ruthenium single-atom catalysts through ultrafast magnetic field-induced quenching synthesis, comprising the following steps: 4 g of ruthenium acetylacetone was dispersed in 20 mL of ethanol solution, followed by immersion of iron foam heated at 700 °C for 5 s. After washing, a self-supported ruthenium single-atom catalyst (named Ru-SA / G-FeO) was obtained. x ).

[0049] Example 8: This embodiment provides a method for preparing a platinum single-atom catalyst through ultrafast magnetic field-induced quenching, comprising the following steps: 4 g of platinum acetylacetone was dispersed in 20 mL of ethanol solution, followed by immersion of iron foam heated at 700 °C for 5 s. After washing, a self-supported platinum single-atom catalyst (named Pt-SA / G-FeO) was obtained. x ).

[0050] Comparative Example 1: This comparative example was prepared using the same method as in Example 1, with a control catalyst (named Ni-SA / FeO) prepared accordingly. x The only difference is that the ethanol solution is replaced with deionized water.

[0051] Comparative Example 2: This comparative example prepared a control catalyst (named G-FeO) using the same method as in Example 1. x The only difference is that the amount of nickel nitrate added is 0.

[0052] Figure 2 , Figure 3 and Figure 4 Ni-SA / G-FeO prepared in Example 1 x Aberration-corrected electron microscopy characterization of the catalyst -1.

[0053] Depend on Figure 2 As can be seen from 3 and 4, a large number of FeO atoms with an average size of 3 nm are uniformly distributed on the graphene surface. x Nanoparticles. The measured 0.20 nm lattice spacing corresponds to the (400) crystal plane of Fe3O4. Numerous isolated bright spots were observed around the nanoparticles, which can be attributed to atomically dispersed Ni species formed during the rapid quenching process. Combined with energy-dispersive spectroscopy, it was confirmed that Ni is uniformly dispersed on the catalyst surface in single-atom form.

[0054] Figure 5 Ni-SA / G-FeO prepared in Example 1 x -1 Catalyst and G-FeO prepared in Comparative Example 2 x The X-ray photoelectron spectrum. (From...) Figure 3 As can be seen, the high-resolution Fe 2p X-ray photoelectron spectrum shows G-FeO x The catalyst has a low binding energy, while Ni-SA / G-FeO x -1 Fe in catalyst 2+ and Fe 3+ The binding energies of all species shifted towards higher energy regions. This positive shift indicates that Ni incorporation induced electron transfer from Fe to Ni. The O 1s spectrum shows Ni-SA / G-FeO x The lattice oxygen peak of the catalyst is compared to that of the original G-FeO.x The catalyst shifts towards the lower binding energy end, indicating an increase in electron density around lattice oxygen after the incorporation of a single Ni atom. Combined with the positive shift observed in the Fe 2p spectrum, these results suggest that the introduction of Ni-SA / G leads to a redistribution of charge within the Fe-O framework, resulting in electron depletion at Fe sites and electron enrichment at coordinated oxygen atoms.

[0055] Test Example 1: A test method for applying an ultrafast magnetic field-induced quenching synthesis of nickel single-atom catalyst to the oxygen evolution reaction, comprising the following steps: Step (1): Self-supporting Ni-SA / G-FeO x -1 catalyst cut into 1 cm pieces 1 cm.

[0056] Step (2): The oxygen evolution reaction was tested using a three-electrode system, with the catalyst described in step (1) as the working electrode, a platinum sheet as the counter electrode, and silver / silver chloride as the reference electrode.

[0057] Step (3): In a 1 M potassium hydroxide electrolyte, linear sweep voltammetry curves were obtained at a scan rate of 5 mV / s to evaluate the oxygen evolution reaction performance. The range of the linear sweep voltammetry curves was 1.1–1.7 V (relative to the reversible hydrogen electrode). Potentiostatic electrolysis was used to evaluate the Ni-SA / G-FeO2 reaction. x The stability of the catalyst in a three-electrode system, with a potential of 1.5 V for constant potential electrolysis (relative to the reversible hydrogen electrode).

[0058] Step (4): Electrolyze water using an anion exchange membrane hydroelectric cell, with the catalyst described in step (1) as the anode and platinum-modified nickel-iron layered hydroxide as the cathode. Both the cathode and anode electrolytes are 1 M potassium hydroxide solution, and the cathode and anode chambers are separated by an anion exchange membrane.

[0059] Step (5): Maintain the cathode / anolyte solution at a flow rate of 10~30 mL / min in the electrolytic cell, and evaluate Ni-SA / G-FeO using constant current electrolysis. x -1. Stability of the catalyst in the electrolyzer, with a constant current density of 1 A / cm² 2 .

[0060] Test Comparison Example 1: The parts that are the same as in Test Example 1 will not be repeated here. The difference is that this test uses the Ni-SA / FeO described in Comparative Example 1. x The catalyst was tested.

[0061] Test Comparison Example 2: The parts that are the same as in Test Example 1 will not be repeated here. The difference is that this test uses the G-FeO described in Comparative Example 2.x The catalyst was tested.

[0062] Test Comparison Example 3: The parts that are the same as in Test Example 1 will not be repeated here. The difference is that this test uses the Co-SA / FeO described in Example 2. x The catalyst was tested.

[0063] Test Comparison Example 4: The parts that are the same as in Test Example 1 will not be repeated here. The difference is that this test uses the Fe-SA / FeO method described in Example 3. x The catalyst was tested.

[0064] Test Comparison Example 5: The parts that are the same as in Test Example 1 will not be repeated here. The difference is that this test uses the Ir-SA / FeO described in Example 4. x The catalyst was tested.

[0065] Test Comparison Example 6: The parts that are the same as in Test Example 1 will not be repeated here. The difference is that this test uses the Ru-SA / FeO described in Example 5. x The catalyst was tested.

[0066] Figure 6 Ni-SA / FeO prepared in Example 1 x Catalyst, Ni-SA / FeO as described in Comparative Example 1 x The catalyst and the G-FeO described in Comparative Example 2 x Linear voltammetric curves of the catalyst; Figure 7 Ni-SA / FeO prepared in Example 1 x Stability graph of catalyst under three-electrode constant voltage test; Figure 8 Ni-SA / G-FeO prepared in Example 1 x -1 Catalyst, Co-SA / G-FeO prepared in Example 2 x Catalyst, Fe-SA / G-FeO prepared in Example 3 x Catalyst, Ir-SA / G-FeO prepared in Example 1 x Catalyst and Ru-SA / G-FeO prepared in Example 1 x Linear voltammetric scan of the oxygen evolution reaction of the catalyst; Figure 9 Ni-SA / G-FeO prepared in Example 1 x -1 Stability diagram of a catalyst-based alkaline anion exchange membrane water electrolyzer.

[0067] Depend on Figure 6It can be seen that in the electrolytic cell test using 1 M potassium hydroxide as the electrolyte, Ni-SA / G-FeO x -1 The catalyst requires only 200 mV overpotential to reach 10 mA / cm². 2 The current density is significantly better than that of Ni-SA / FeO. x and G-FeO x Catalyst. Nickel-free G-FeO x Catalyst compared to Ni-SA / G-FeO x -1 exhibits significantly lower oxygen evolution activity, suggesting that surface-bound nickel single-atom sites may be the main active centers.

[0068] Depend on Figure 7 It can be seen that Ni-SA / G-FeO x The catalyst showed no significant current decay after 330 hours of continuous operation at 1.5 V (relative to the reversible hydrogen electrode), demonstrating its great potential in industrial applications.

[0069] Depend on Figure 8 It can be seen that Co-SA / G-FeO x Fe-SA / G-FeO x Ir-SA / G-FeO x and Ru-SA / G-FeO x All catalysts exhibited oxygen evolution properties. These results highlight the remarkable versatility of ultrafast magnetic field-induced quenching synthesis of single-atom catalysts.

[0070] Depend on Figure 9 It can be seen that, in industrial applications, the relevant current density is 1000 mA / cm². 2 Lower Ni-SA / G-FeO x The Ni-SA / G-FeO catalyst operated stably for over 240 hours without significant performance degradation. x The alkaline anion exchange membrane electrolyzer with the -1 catalyst surpasses most reported non-precious metal systems, demonstrating its enormous application potential in practical large-scale hydrogen production.

[0071] It should be noted that the examples described are for illustrative purposes only and do not constitute any limitation on the invention. Based on this invention, some modifications and improvements can be made, which will be obvious to those skilled in the art. Therefore, any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention are within the scope of protection claimed by this invention.

Claims

1. A method for preparing a single-atom catalyst by ultrafast magnetic field-induced quenching synthesis, characterized in that, Includes the following steps: Step 1: Disperse the precursor in ethanol to obtain a precursor dispersion. Step 2: The current collector is heated using a high-frequency induction heater, and then the annealed current collector is immersed in the precursor dispersion at room temperature for rapid quenching, followed by cleaning to obtain a self-supporting single-atom catalyst.

2. The method for preparing a single-atom catalyst by ultrafast magnetic field-induced quenching synthesis according to claim 1, characterized in that, The precursor is one or more of a single metal nitrate, chloride, sulfate, and acetate, wherein the single metal is nickel, cobalt, iron, iridium, ruthenium, or platinum.

3. The method for preparing a single-atom catalyst by ultrafast magnetic field-induced quenching synthesis according to claim 1 or 2, characterized in that, The mass-to-volume ratio of the precursor to ethanol is (2~8) g: 10~30 mL.

4. The method for preparing a single-atom catalyst by ultrafast magnetic field-induced quenching synthesis according to claim 1 or 2, characterized in that, The current collector is one or more of nickel foam, iron foam, and copper foam.

5. The method for preparing a single-atom catalyst by ultrafast magnetic field-induced quenching synthesis according to claim 1 or 2, characterized in that, The current collector is heated using a high-frequency induction heater to a temperature of 500~1000℃ for a duration of [duration missing]. 10 s.

6. The method for preparing a single-atom catalyst by ultrafast magnetic field-induced quenching synthesis according to claim 5, characterized in that, The surface area of ​​the current collector is 1~100 cm². 2 The heating temperature is 600~900℃ and the time is 3~8s.

7. The method for preparing a single-atom catalyst by ultrafast magnetic field-induced quenching synthesis according to claim 5, characterized in that, The frequency of the high-frequency induction heater is 30-100 kHz, and the current is 1-50 A.

8. The method for preparing a single-atom catalyst by ultrafast magnetic field-induced quenching synthesis according to claim 1, characterized in that, The high-frequency induction heating process forms a thin layer of metal oxide on the surface of the current collector, providing an active substrate for subsequent single-atom anchoring; the cleaning includes sequential deionized water cleaning and ethanol cleaning; the number of times the deionized water cleaning is performed is 2 to 4, and the number of times the ethanol cleaning is performed is 2 to 4.

9. A single-atom catalyst, obtained by the preparation method of the ultrafast magnetic field-induced quenching synthesis of a single-atom catalyst as described in any one of claims 1 to 8, wherein the single atom is supported on a graphene layer carbonized by rapid decomposition of ethanol, and the single-atom loading is 1 to 10% by weight.

10. The application of the single-atom catalyst of claim 9 as an electrode without the need for a binder, wherein the electrode is used for hydrogen production by water electrolysis.

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