A proton sponge modified fluorine atom doped copper electrode material and a preparation method and application thereof

Abstract

The application relates to the development and technical field of electrocatalysts, and discloses a preparation method and application of a proton sponge modified fluorine atom doped metal copper electrode material, which comprises the following steps: adding a dispersion solution of a proton sponge into a dispersion solution of a hydroxyl copper fluoride precursor to obtain a mixed solution; uniformly spraying the mixed solution on a polytetrafluoroethylene film substrate loaded with copper nanoparticles to obtain a proton sponge modified hydroxyl copper fluoride precursor electrode material; and then electrochemically reducing the proton sponge modified hydroxyl copper fluoride precursor electrode material to obtain the proton sponge modified fluorine atom doped metal copper electrode material. The application further discloses the proton sponge modified fluorine atom doped metal copper electrode material obtained by the above preparation method and application of the proton sponge modified fluorine atom doped metal copper electrode material to an electro-reduction carbon dioxide reaction as a working electrode. The electrode material provided by the application exhibits excellent electro-reduction CO2 performance in an acidic environment, and realizes the preparation of high-value C 2+ products with high selectivity under an industrial-grade current density.

Description

Technical Field

[0001] This invention relates to the field of electrocatalyst development and technology, specifically to a proton sponge-modified fluorine atom-doped metallic copper electrode material, its preparation method, and its application. Background Technology

[0002] The renewable energy-driven electroreduction of carbon dioxide (CO2) offers a promising technological pathway for the capture, conversion, and utilization of CO2. This technology enables the efficient conversion and utilization of CO2 using renewable electricity under mild conditions. Among the CO2 components, ethylene (C2H4), ethanol (C2H5OH), acetic acid (CH3COOH), and propanol (C3H7OH) are high-energy-density carbon dioxide (C4) compounds. 2+ Chemical compounds, as ideal value-added products, not only provide green raw materials for the chemical industry but also effectively alleviate the contradiction between climate change and energy demand, thus attracting widespread attention from academia and industry. Currently, in order to improve C... 2+ Regarding product selectivity, most electroreduction CO2 reactions use alkaline or neutral electrolytes. However, in alkaline or neutral environments, the carbonates formed during CO2 electroreduction can precipitate at the cathode or migrate to the anode, leading to CO2 cross-contamination and reducing CO2 utilization efficiency. Furthermore, the regeneration process requires significant additional energy consumption. In contrast, electroreduction CO2 reactions in acidic environments can reduce proton (H+) in the electrolyte. + H+ combines with carbonates to convert into CO2, thereby improving overall energy efficiency, but this is accompanied by a large amount of H+. + Preferential combination occurs in the hydrogen evolution side reaction of water electrolysis, leading to C 2+ The reduced selectivity of the products means that developing electrocatalysts that can significantly improve the performance of CO2 electroreduction under acidic conditions and effectively suppress hydrogen evolution side reactions still faces significant challenges.

[0003] To date, copper-based catalysts have been widely used in the electroreduction of CO2 due to their unique electronic structure and excellent carbon-carbon (CC) coupling ability. Most studies have focused on enhancing the intrinsic catalytic activity of copper-based catalysts by controlling their electronic structure and chemical composition. Common control strategies include element doping, crystal facet manipulation, defect formation, and alloying. Among these, the core advantage of element doping lies in its precise control over the catalyst's "electronic structure-geometry-surface properties," thereby overcoming the performance limitations of single-element components. For example, Chinese patent document CN119433589A discloses an in-situ synthesized halogen-modified bismuth nano-electrocatalytic electrode, its preparation method, and its application. Halogen atoms are grafted onto the surface of basic copper bismuthate through a water bath treatment to synthesize a precursor, which is then electrochemically reduced to obtain halogen-modified bismuth nanomaterials. This effectively inhibits the hydrogen evolution reaction, increases the reaction current density, and demonstrates excellent performance in the electroreduction of CO2 to formic acid.

[0004] As research into improving the performance of CO2 electroreduction reactions deepens, it is no longer limited to optimizing the intrinsic properties of electrocatalysts, but is gradually shifting towards regulating the microenvironment of the reaction interface of electrode materials, providing a new approach to improving the performance of CO2 electroreduction reactions. For example, Chinese patent document CN119593013A discloses a method for preparing and applying a CO2 gas-capturing functional molecule-modified nano-gold catalyst. The functional molecule is added to an organic solvent and then reacted with the nano-gold catalyst in an oil bath under heating to obtain an organic molecule-modified nano-gold catalyst with CO2 gas-capturing function. The organic molecule modification provides a hydrophobic microenvironment conducive to the CO2 reduction reaction, significantly enhancing CO2 gas diffusion and effectively reducing hydrogen evolution side reactions, thus improving the selectivity of the CO2 electroreduction reaction.

[0005] While some progress has been made in the study of catalyst modification and microenvironment regulation of the reaction interface for electroreduction of CO2, many challenges remain in achieving high selectivity and stability of the electroreduction of CO2 under acidic conditions and clarifying its microscopic reaction mechanism. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing a proton sponge (1,8-bis(dimethylaminonaphthalene)) modified fluorine atom-doped metallic copper electrode material. The prepared proton sponge modified fluorine atom-doped metallic copper electrode material exhibits excellent electroreduction performance of CO2 in acidic environments at industrial-grade current densities.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing a proton-sponge-modified fluorine-doped metallic copper electrode material, the method comprising the following steps:

[0009] (1) The dispersion of proton sponge (1,8-bis(dimethylaminonaphthalene)) was added to the dispersion of copper hydroxyfluoride precursor to obtain a mixed solution;

[0010] (2) The mixed solution was sprayed onto a polytetrafluoroethylene film substrate loaded with copper nanoparticles to obtain a proton sponge modified copper hydroxy fluoride precursor electrode material.

[0011] (3) The proton sponge-modified hydroxy copper fluoride precursor electrode material prepared in step (2) is electrochemically reduced to obtain a proton sponge-modified fluorine atom-doped metallic copper electrode material.

[0012] The preparation principle of the proton sponge-modified fluorine-doped copper electrode material provided by this invention is as follows: A copper hydroxyfluoride (Cu(OH)F) precursor is mixed with a proton sponge and uniformly sprayed onto a polytetrafluoroethylene (PTFE) thin film substrate loaded with copper nanoparticles to obtain a proton sponge-modified Cu(OH)F precursor electrode material. This material is then subjected to constant current electrochemical reduction to obtain the proton sponge-modified fluorine-doped copper electrode material. Fluorine doping of copper promotes the migration of hydrated potassium ions to the electrode interface while repelling H+ ions. + Ion migration is used to suppress the hydrogen evolution side reaction. The local electric field at the reaction interface is effectively modulated by introducing a proton sponge onto the electrode surface, altering the dipole moment of the intermediate *CO to enhance its adsorption. This lowers the reaction energy barrier for C / C coupling and improves the preparation of high-value-added C. 2+ The performance of the product.

[0013] Preferably, in step (1), the preparation method of the hydroxy copper fluoride precursor is as follows: after dissolving the inorganic copper salt in N,N-dimethylformamide solvent, ammonium bifluoride is added and stirred and mixed, followed by hydrothermal reaction and centrifugation and drying to obtain the hydroxy copper fluoride precursor.

[0014] In a mixed solution of N,N-dimethylformamide in which copper nitrate is uniformly dispersed, ammonium bifluoride is added as a fluorine source, and a precursor of copper hydroxyfluoride (Cu(OH)F) is synthesized under weakly alkaline conditions via a high-temperature hydrothermal reaction. In this invention, the use of a weakly alkaline solution and ammonium bifluoride is beneficial for synthesizing a more uniform copper hydroxyfluoride precursor.

[0015] Preferably, the inorganic copper salt is copper nitrate trihydrate.

[0016] Preferably, the mixing time is 15-30 minutes. Preferably, the mixing time is 30 minutes.

[0017] Preferably, the hydrothermal reaction temperature is 120–160°C, and the reaction time is 2–4 hours. If the hydrothermal temperature is too low, a highly crystalline, sturdy Cu(OH)F precursor cannot be formed; if the hydrothermal time is too short, the complete reaction of the copper ions cannot be guaranteed. Preferably, the hydrothermal reaction temperature is 160°C, and the reaction time is 4 hours.

[0018] In step (1), the proton sponge and the copper hydroxyfluoride precursor are dissolved in a solvent to form a dispersion; the solvent is methanol, ethanol, or isopropanol. Preferably, the solvent is methanol.

[0019] In step (1), the mass ratio of the proton sponge to the copper hydroxyfluoride precursor is 0.04–0.065:1. When the mass ratio is low, it enhances the adsorption of the intermediate *CO and its conversion to C. 2+ The effect of the product is not obvious; when its mass ratio is high, single C 2+ The selectivity of the product ethylene (C2H4) decreases. Preferably, the mass ratio of the proton sponge to the copper hydroxyfluoride precursor is 0.05–0.065:1, which is beneficial for improving the selectivity of single C4. 2+ Selectivity of the product ethylene (C2H4).

[0020] In step (2), the loading amount of the proton sponge-modified copper fluoride precursor on the polytetrafluoroethylene film substrate loaded with copper nanoparticles is 0.5–1 mg cm⁻¹. -2 Preferably, the loading amount of the proton-loaded sponge-modified copper hydroxyfluoride precursor is 1 mg cm⁻¹. -2 .

[0021] In step (2), the thickness of the copper nanoparticle layer loaded on the polytetrafluoroethylene film is 200–400 nm. Thicker copper nanoparticles help enhance the conductivity of the substrate. Preferably, the thickness of the copper nanoparticle layer is 400 nm.

[0022] In step (3), the constant current density of the electrochemical reduction is 50–100 mA cm⁻¹. -2 The time is 100–300 s. Preferably, the constant current density of the electrochemical reduction is 100 mA cm⁻¹. -2 The time is 300 seconds.

[0023] The present invention also provides a proton sponge-modified fluorine atom-doped metallic copper electrode material obtained according to the above preparation method.

[0024] In the proton-sponge modified fluorine-doped copper electrode material, the mass ratio of the proton-sponge to the copper hydroxyfluoride precursor is 0.04–0.065:1, and the thickness of the copper nanoparticle layer on the polytetrafluoroethylene film is 200–400 nm.

[0025] The present invention also provides a copper electrode material modified with fluorine atoms and described above as a working electrode for use in the electroreduction of CO2 reaction.

[0026] Furthermore, the proton-sponge-modified fluorine-doped copper electrode material is used as a working electrode to achieve the electroreduction of CO2 in an acidic environment at industrial-grade current densities.

[0027] The proton-sponge-modified fluorine-doped copper electrode material provided by this invention exhibits high performance as a working electrode at industrial-grade current densities (200–1000 mA / cm²). -2 Excellent electroreduction performance of CO2 under acidic conditions.

[0028] The proton-sponge modified fluorine-doped copper electrode material provided by this invention promotes the enrichment of hydrated potassium ions at the reaction interface and inhibits H+ ions. + The migration of ions to the electrode interface significantly reduces the hydrogen evolution side reaction. Simultaneously, the proton sponge modification effectively modulates the local electric field strength at the reaction interface, influencing the dipole moment of the intermediate *CO to enhance its adsorption, and lowering the reaction energy barrier of C / C coupling to increase the yield of high-value-added C. 2+ The properties of the product are of practical significance for realizing the electroreduction of CO2 in an acidic environment under industrial conditions.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The proton-sponge-modified fluorine-doped copper electrode material provided by this invention enables highly selective electroreduction of CO2 to produce high-value-added CO2 under acidic conditions. 2+ The product's performance provides possibilities for further industrial applications;

[0031] (2) The proton-sponge-modified fluorine-doped copper electrode material provided by this invention achieves an enrichment effect of hydrated potassium ions at the electrode interface through fluorine atom doping, thereby suppressing H+ ions. + Ion migration to the electrode interface effectively reduces hydrogen evolution side reactions. The introduction of the proton sponge helps to regulate the local electric field strength at the electrode reaction interface, enhances the adsorption of intermediate *CO, lowers the energy barrier of the C / C coupling reaction, and thus promotes the formation of C. 2+ The product demonstrates excellent performance in the acidic electroreduction of CO2 at industrial-grade current densities. Attached Figure Description

[0032] Figure 1 This is a scanning electron microscope image of the precursor Cu(OH)F prepared in Example 1;

[0033] Figure 2The X-ray diffraction pattern of the Cu-F electrode material prepared in Example 1;

[0034] Figure 3 The X-ray photoelectron spectrum of the electrode material Cu-F prepared in Example 1 is shown below.

[0035] Figure 4 The electrode material prepared in Example 1, when used in application examples with electrolyte pH = 1.5 and pH = 1.0, exhibited an energy density of 100–1000 mA / cm². -2 C2H4 and C within the current density range 2+ The Faraday efficiency of the product;

[0036] Figure 5 The electrode materials prepared in Examples 1-3, when used in the application example with an electrolyte pH of 1.5, exhibited an efficiency of 100-1000 mA / cm². -2 C2H4 and C within the current density range 2+ The Faraday efficiency of the product;

[0037] Figure 6 The electrode materials prepared for Example 1 and Comparative Example 1, in the application example with an electrolyte pH of 1.5, exhibited an energy density of 100–1000 mA / cm². -2 The Faraday efficiency of electroreduction of CO2 to obtain different products within the current density range;

[0038] Figure 7 The electrode materials prepared in Comparative Examples 1-5, when used in applications with an electrolyte pH of 1.5, achieved a 500 mA cm⁻¹ performance. -2 Faraday efficiency of CO2 electroreduction to obtain different products at current density;

[0039] Figure 8 The electrode material prepared in Example 1, in the application example with electrolyte pH = 1.5, achieved a 200 mA cm⁻¹ performance. -2 Stability test at current density. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention. Modifications or equivalent substitutions made by those skilled in the art based on their understanding of the technical solutions of this invention, without departing from the spirit and scope of the technical solutions of this invention, should all be covered within the protection scope of this invention. The raw materials used in the following specific embodiments are all commercially available.

[0041] Example 1

[0042] (1) Weigh 483.2 mg of copper nitrate trihydrate solid particles and dissolve them in 50 mL of N,N-dimethylformamide solvent. Stir at room temperature until completely dissolved. Then add 114.1 mg of ammonium bifluoride solid particles and stir for 30 min. Transfer the resulting mixed solution to a 100 mL hydrothermal reactor and react hydrothermally at 160 °C for 4 h. Then centrifuge and wash with water and ethanol more than 3 times each. Finally, dry in a vacuum oven at 60 °C overnight to obtain the hydroxy copper fluoride precursor.

[0043] (2) Weigh 20 mg of the hydroxy copper fluoride precursor obtained in step (1) and disperse it in 2.5 mL of methanol and 80 μL of Nafion dispersion. Dissolve the proton sponge in methanol solution to obtain a 40-60 mM dispersion. Then, measure 100 μL of the 50 mM proton sponge dispersion in methanol and add it to the dispersion of the hydroxy copper fluoride precursor. After mixing evenly, the mass ratio of the proton sponge to the hydroxy copper fluoride precursor is 0.0536:1.

[0044] (3) Measure the mixed solution prepared in step (2) and spray it evenly to a depth of 2*2cm. 2 On a copper nanoparticle polytetrafluoroethylene film substrate, the substrate mass was weighed before and after to achieve a loading of 1 mg / cm³. -2 In a 3M KCl (pH=1.5) electrolyte, 100mA cm -2 Under constant current density, a constant current reduction reaction was carried out for 300 s to obtain a proton sponge-modified fluorine atom-doped metallic copper electrode material.

[0045] The macroscopic morphology of the prepared copper hydroxyfluoride precursor was observed using a scanning electron microscope, and the results are as follows: Figure 1 As shown, its morphological structure is sheet-like. The X-ray diffraction pattern of the proton sponge-modified fluorine-doped copper electrode material is shown below. Figure 2 As shown, the characteristic peaks of the crystalline phase of metallic copper can be observed. The X-ray photoelectron spectrum of the proton-sponge-modified fluorine-doped metallic copper electrode material prepared in this embodiment is shown below. Figure 3 As shown, the characteristic peaks of fluorine doping can be observed, indicating the successful preparation of proton sponge-modified fluorine-doped copper electrode material.

[0046] Example 2

[0047] According to the preparation process of Example 1, the 50mM proton sponge in methanol dispersion in step (2) was changed to 40mM, while the other steps remained unchanged, and the mass ratio of proton sponge to copper hydroxyfluoride precursor was 0.0429:1.

[0048] Example 3

[0049] According to the preparation process of Example 1, the 50mM proton sponge in methanol dispersion in step (2) was changed to 60mM, while the other steps remained unchanged, and the mass ratio of proton sponge to copper hydroxyfluoride precursor was 0.0643:1.

[0050] Comparative Example 1

[0051] Following the preparation process of Example 1, without performing step (2) of adding 100 μL of a dispersion of 50 mM proton sponge dissolved in methanol to the dispersion of the copper hydroxyfluoride precursor, the remaining steps remain unchanged to obtain a fluorine-doped copper electrode material.

[0052] Comparative Example 2

[0053] Following the preparation process of Comparative Example 1, the addition of 114.1 mg of ammonium bifluoride solid particles in step (1) was omitted, and step (1) was changed to hydrothermal reaction at 220°C for 36 h to obtain pure metallic copper electrode material.

[0054] Comparative Example 3

[0055] Following the preparation process of Comparative Example 1, 300 mg of ammonium chloride was dissolved in a 50 mL mixture of ethanol and water at a volume ratio of 49:1. Then, 50 mg of the copper hydroxyfluoride precursor prepared in step (1) was added. After stirring at room temperature for 36 h, the mixture was washed and dried to obtain the copper hydroxychloride precursor. The copper hydroxyfluoride precursor in step (2) was replaced with the copper hydroxychloride precursor to obtain a chlorine-doped copper electrode material.

[0056] Comparative Example 4

[0057] Following the preparation process of Comparative Example 1, 300 mg of ammonium bromide was dissolved in a 50 mL mixture of ethanol and water at a volume ratio of 49:1. Then, 50 mg of the hydroxycopper fluoride precursor prepared in step (1) was added. After stirring at room temperature for 36 h, the mixture was washed and dried to obtain the hydroxycopper bromide precursor. The hydroxycopper fluoride precursor in step (2) was replaced with the hydroxycopper bromide precursor to obtain bromine-doped copper electrode material.

[0058] Comparative Example 5

[0059] Following the comparative preparation process, 300 mg of ammonium iodide was dissolved in a 50 mL mixture of ethanol and water at a volume ratio of 49:1. Then, 50 mg of the copper hydroxyfluoride precursor prepared in step (1) was added. After stirring at room temperature for 36 h, the mixture was washed and dried to obtain the cuprous iodide precursor. The copper hydroxyfluoride precursor in step (2) was replaced with the cuprous iodide precursor to obtain iodine-doped copper electrode material. Application example: Electroreduction of CO2 in an acidic environment at industrial-grade current density.

[0060] First, the electrode material prepared above was used as the working electrode in a three-electrode flow electrolysis cell measuring device, with a cation exchange membrane (Nafion 117) separating the flow chambers on both sides of the device. The cathode electrolyte was prepared using 3.0M KCl solutions (adjusted with 0.5M H2SO4 solution) at pH=1.5 and pH=1.0, respectively, while the anolyte was 0.05M H2SO4. The reference electrode and counter electrode were a platinum sheet and a silver / silver chloride electrode, respectively.

[0061] Cyclic voltammetry (CV) activation: A Shanghai Chenhua CHI 760E electrochemical workstation was used with a CV program. The test range was -0.5 to -1.9 V vs. RHE, and the scan rate was 50 mV / s. -1 After 30 cyclic scans, the electrode reaches a stable state.

[0062] Linear sweep voltammetry (LSV) test: After CV activation, switch the program to LSV, with a test range of -0.5 to -1.9 V vs. RHE, and a scan rate of 5 mV / s. -1 .

[0063] Faraday efficiency (FE) test: The program is switched to constant current-time test. During the constant current test, the concentration of gaseous products is quantitatively determined online using gas chromatography (GC, Fuli 9790II), and the concentration of liquid products is analyzed and determined using nuclear magnetic resonance. The Faraday efficiency of all products is calculated.

[0064] The proton sponge-modified fluorine-doped copper electrode material prepared in Example 1 was subjected to an amplitude of 100–1000 mA / cm². -2 It exhibited excellent performance in the acidic electroreduction of CO2 within the current range, as shown in the results. Figure 4 As shown, at electrolyte pH = 1.5 and pH = 1.0, at 500 mA cm⁻¹ -2 At the given current density, the Faraday efficiencies of the C2H4 products reached 56.8% and 52.6%, respectively. 2+ The maximum Faraday efficiencies of the products reached 79.5% and 71.5%, respectively, in the range of 100–1000 mA cm⁻¹. -2 Within the current density range, the selectivity of C2H4 products remains above 41%.

[0065] The proton sponge-modified fluorine-doped copper electrode materials prepared in Examples 1-3 were subjected to 100-1000 mA cm⁻¹. -2 C2H4 and C within the current range 2+ The comparison of the products yielded the following results: Figure 5 As shown, the performance of Example 1 is better than that of Example 2 and Example 3.

[0066] The electrode materials prepared in Example 1 and Comparative Example 1 were subjected to an A / cm test at 100–1000 mA. -2 The performance of acidic electroreduction of CO2 within the current density range was compared, and the results are as follows: Figure 6 As shown in Table 1, the proton sponge-modified fluorine-doped copper electrode material prepared in Example 1 performs significantly better than Comparative Example 1 in an acidic environment.

[0067] Table 1 shows the electrode materials prepared in Example 1 and Comparative Example 1 at 100–1000 mA cm⁻¹. -2 Acidic electroreduction performance of CO2 within the current density range

[0068]

[0069] The halogen-doped copper electrode materials prepared in Comparative Examples 1-5 and the pure copper electrode materials were subjected to a 500 mA cm⁻¹ test. -2 The performance of acidic electroreduction of CO2 at different current densities was compared, and the results are as follows: Figure 7 As shown in Table 2, Comparative Example 1 has the lowest hydrogen production Faraday efficiency. Compared with pure copper electrode material, halogen atom doping significantly suppresses the occurrence of hydrogen evolution side reactions.

[0070] Table 2 shows the halogen-doped copper electrode materials and pure copper electrode materials prepared in Comparative Examples 1-5 at 500 mA / cm². -2 Comparison of the performance of acidic electroreduction of CO2 at current density

[0071]

[0072] The stability of the electrode material prepared in Example 1 was tested in a flowing electrolytic cell, and the results are as follows: Figure 8 As shown, at 200mA cm -2 It can operate stably for 24 hours at a current density, and the Faraday efficiency of the C2H4 product remains above 40%.

Claims

1. A method for preparing a proton-sponge-modified fluorine-doped metallic copper electrode material, characterized in that, The preparation method includes the following steps: (1) The dispersion of proton sponge was added to the dispersion of copper hydroxyfluoride precursor to obtain a mixed solution; (2) The mixed solution was sprayed onto a polytetrafluoroethylene film substrate loaded with copper nanoparticles to obtain a proton sponge modified copper hydroxy fluoride precursor electrode material. (3) The proton sponge-modified copper hydroxy fluoride precursor electrode material prepared in step (2) is electrochemically reduced to obtain a proton sponge-modified fluorine atom-doped metallic copper electrode material. In step (1), the mass ratio of the proton sponge to the copper hydroxyfluoride precursor is 0.04~0.065:1; In step (3), the constant current density for electrochemical reduction is 50~100 mA•cm in an electrolyte of 3 M KCl and pH = 1.

5. -2 The duration is 100~300 s.

2. The method for preparing the proton-sponge-modified fluorine-doped metallic copper electrode material according to claim 1, characterized in that, In step (1), the preparation method of the hydroxy copper fluoride precursor is as follows: after dissolving the inorganic copper salt in N,N-dimethylformamide solvent, ammonium bifluoride is added and stirred and mixed, and after solvothermal reaction, it is centrifuged and dried to obtain the hydroxy copper fluoride precursor.

3. The method for preparing the proton-sponge-modified fluorine-doped metallic copper electrode material according to claim 2, characterized in that, The solvothermal reaction temperature is 120~160 ℃, and the solvothermal reaction time is 2~4 h.

4. The method for preparing the proton-sponge-modified fluorine-doped metallic copper electrode material according to claim 1, characterized in that, In step (2), the thickness of the copper nanoparticle layer on the polytetrafluoroethylene film is 200~400 nm.

5. The method for preparing the proton-sponge-modified fluorine-doped metallic copper electrode material according to claim 1, characterized in that, In step (2), the loading amount of the proton sponge-modified copper hydroxyfluoride precursor on the polytetrafluoroethylene film-supported copper nanoparticle substrate is 0.5~1 mg•cm. -2 .

6. A proton-sponge-modified fluorine-doped metallic copper electrode material obtained by any one of the preparation methods of claims 1-5.

7. A proton-sponge-modified fluorine-doped copper electrode material as described in claim 6 is used as a working electrode in the electroreduction of carbon dioxide.

8. The application according to claim 7, characterized in that, The proton-sponge-modified fluorine-doped copper electrode material is used as the working electrode to realize the electroreduction of carbon dioxide in an acidic environment at industrial-grade current density.

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