Electrocatalytic carbon dioxide reduction catalysts, methods of making and using the same

Abstract

The application provides an electrocatalytic carbon dioxide reduction catalyst and a preparation method and application thereof, comprising a carbon substrate and a diatomic active site anchored on the carbon substrate; the diatomic active site comprises Te atoms and M atoms, the Te atoms and the M atoms are directly connected through a chemical bond; the M atoms are bonded to the carbon substrate through nitrogen atoms, and the Te atoms are indirectly loaded on the carbon substrate through the bonding with the M atoms, forming an M-N3-Te coordination configuration. The structure constructs an asymmetric coordination field with the aid of Te, on one hand, the d-band center of the metal M is reduced through the electron-donating effect of Te, thereby optimizing CO adsorption and reducing the COOH generation energy barrier; on the other hand, the H adsorption on the Te site is weak, thereby significantly inhibiting the hydrogen evolution side reaction. The catalyst has excellent performance under an industrial-grade current density. The application has low energy consumption, high selectivity and long service life, and the preparation process is simple, and has the potential for large-scale application.

Description

Technical Field

[0001] This invention belongs to the field of carbon dioxide electrocatalytic reduction technology, specifically relating to electrocatalytic carbon dioxide reduction catalysts, their preparation methods and applications, and more specifically to highly efficient electrocatalytic reduction catalysts for carbon monoxide to carbon dioxide, their preparation methods and applications. Background Technology

[0002] Electrocatalytic carbon dioxide reduction, driven by renewable electricity, converts CO2 into high-value-added fuels and chemicals through electrochemical reduction reactions, representing a potential pathway for closing the carbon cycle and achieving renewable energy conversion. Among a series of carbon dioxide reduction reaction pathways, the one that produces CO exhibits high selectivity, rapid reaction kinetics, fewer byproducts, and easier product separation.

[0003] While noble metals such as Ag and Au exhibit excellent performance in catalyzing the conversion of CO2 to CO, their high cost and scarcity significantly limit their application. Transition metals, on the other hand, are abundant and their unfilled d-orbitals are conducive to CO2 activation, making them highly promising alternative candidates. Among various catalyst synthesis methods, single-atom catalysts are promising low-cost CO2 reduction catalysts due to their maximum utilization of transition metal atoms, exhibiting both excellent activity and stability. However, most reported single-atom catalysts currently use a metal atom (M) coordinated with four nitrogen atoms to form an M-N4 active center, anchored on a carbon-based support, exhibiting an M-N4-C coordination configuration. Although this structure of single-atom catalysts possesses relatively superior catalytic performance, it still cannot compare with noble metal catalysts such as Au and Ag. Therefore, modifications to the original structure are necessary, such as introducing another transition metal to form a diatomic catalyst, or altering the coordination environment of the metal atom by introducing defects. Patent application CN117568857A discloses a strategy of modifying Ni-based single-atom catalysts using N and P co-doping to optimize the electronic structure of Ni active sites, significantly improving the selectivity and current density of CO2 reduction to CO. However, this method still cannot achieve high current densities (maximum 91.2 mA / cm² in a flow cell). 2 The catalytic reaction is carried out under certain conditions, which greatly limits its application prospects under high current in industrial applications.

[0004] In recent years, some studies have attempted to incorporate tellurium (Te) into transition metal-based catalysts to construct diatomic sites. For example, a Fe-Te diatomic site catalyst, characterized as N3Fe-TeC3, has been reported, where Fe and Te are only spatially adjacent without forming a direct chemical bond. This catalyst is used for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). Wang et al. (Chinese Journal of Catalysis, 2024) incorporated chalcogenide X into a Ni-NC single-atom catalyst, forming an asymmetric coordination structure Ni-X-N3-C for CO2 electroreduction. However, the coordination mechanism involves X being bridged by nitrogen atoms (Ni-X-N3), rather than a direct bond between chalcogenide X and Ni. Summary of the Invention

[0005] The present invention aims to solve the above-mentioned problems of the prior art, and its purpose is to provide an electrocatalytic carbon dioxide reduction catalyst, its preparation method and application.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, an electrocatalytic carbon dioxide reduction catalyst is provided, comprising a carbon substrate and a diatomic active site anchored on the carbon substrate; the diatomic active site comprises a Te atom and an M atom, the Te atom and the M atom being directly connected by a chemical bond; the M atom is bonded to the carbon substrate through a nitrogen atom, and the Te atom is indirectly supported on the carbon substrate through a bond with the M atom, forming an M-N3-Te coordination configuration; wherein, M is selected from one or more transition metals selected from Co, Zn, Fe, Ni, and Ti.

[0007] Secondly, a method for preparing an electrocatalyst for carbon dioxide reduction is provided, including: A precursor solution is prepared using organic matter containing nitrogen and carbon, a soluble transition metal salt, and a Te-containing compound as raw materials. The precursor solution undergoes a solvothermal reaction, and the resulting product is subjected to solid-liquid separation, washing, and freeze-drying to obtain a catalyst precursor. The soluble transition metal salt is a soluble salt of one or more transition metals selected from Co, Zn, Fe, Ni, and Ti. The catalyst precursor is annealed under a weak oxidizing atmosphere to obtain an electrocatalyst for carbon dioxide reduction with an M-N3-Te coordination structure; the volume fraction of oxygen in the weak oxidizing atmosphere is 0.5-1%.

[0008] Thirdly, a working electrode for electrocatalytic CO2 reduction is provided, wherein the catalytically active material of the working electrode is the electrocatalytic carbon dioxide reduction catalyst described in the first aspect, or the electrocatalytic carbon dioxide reduction catalyst prepared by the preparation method described in the second aspect.

[0009] Fourthly, the application of the working electrode for electrocatalytic CO2 reduction described in the third aspect in the electrocatalytic reduction of carbon dioxide to produce CO is provided.

[0010] Compared with the prior art, one or more of the above technical solutions can achieve at least one of the following beneficial effects: 1) A direct M-N3-Te coordination configuration was achieved in the CO2RR catalyst, breaking the structural constraints of the traditional single-site M-N4 coordination. This differs from existing technologies where Fe and Te coordinate independently with nitrogen (e.g., Fe-N4, Te-N). x Compared to systems lacking direct M-Te bonding and with weak electronic interactions, this invention introduces Te atoms into the active center. Through precise control, Te forms M-Te bonds with M. Theoretical calculations and XPS confirm a significant electron transfer from Te to M, resulting in a synergistic catalytic effect that surpasses simple bimetallic doping. Compared to existing bimetallic doping systems, this invention significantly lowers the energy barrier of the rate-determining step of CO2→*COOH while substantially increasing the overpotential of the hydrogen evolution reaction, thus maintaining extremely high CO selectivity even under high current.

[0011] 2) Excellent catalytic performance at industrial-grade high current densities: Thanks to the unique active site design, the catalyst of this invention exhibits excellent catalytic performance at -100 to -350 mA·cm⁻¹. -2 It maintains high catalytic activity over a wide industrial-grade current density range. At -200 mA·cm⁻¹ -2 At the specified current density, the Faraday efficiency of CO products can reach up to 99.5%, while the H2 side reaction is as low as 0.04%, almost completely suppressed, and can operate stably for more than 10 hours.

[0012] 3) The catalyst provided has a multi-level structure, which is conducive to exposing active sites and providing good mass transfer channels, synergistically achieving high current density, fast reaction kinetics and long-term operational reliability.

[0013] 4) This invention provides a preparation route that is fundamentally different from existing template methods / vapor phase doping methods. The invention adopts a combined process of "one-step solvothermal-freeze-weak oxidation annealing", which does not require pre-synthesis of MOF or the addition of external carbon support, and is applicable to a variety of transition metals such as Ni, Co, and Zn, and has good versatility and scalability potential. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a flowchart illustrating the synthesis process of the Te-doped transition metal-based single-atom catalyst of this invention. Figure 2 This is a schematic diagram of the reaction mechanism of the Te-doped Ni-based single-atom catalyst of the present invention. In the diagram, a represents the undoped Ni-N4 model anchored on a carbon substrate, b represents the Te-doped Ni-N3-Te model anchored on a carbon substrate, c represents the schematic diagram of the three main steps of the catalytic conversion of CO2→CO by the catalyst, d represents the Gibbs free energy of the reaction intermediates of the two catalysts in the CO2RR process, e represents the Gibbs free energy of the reaction intermediates of the two catalysts in the HER process, and f represents the differential charge density diagram of the Ni-N3-Te catalyst.

[0016] Figure 3 The apparatus used to test the catalytic performance of Te-doped transition metal-based single-atom catalysts and pure transition metal-based single-atom catalysts is shown in Figure (a) and its cross-sectional view is shown in Figure (b).

[0017] Figure 4 The images show the XPS spectra of the Ni-N3-Te sample obtained in Example 1 and the Ni-N4-C sample obtained in the comparative example, as well as the surface composition and chemical state of each element. (a) and (b) represent the high-resolution XPS spectra of C 1s and N 1s of the undoped Te sample (Ni-N4-C), respectively; (c) and (d) represent the high-resolution XPS spectra of C 1s and N 1s of the Te-doped sample (Ni-N3-Te); and (e) and (f) represent the high-resolution XPS spectra of Ni 2p and Te 3d.

[0018] Figure 5 The images show SEM and TEM images of the Ni-N3-Te catalyst of Example 1 and the Ni-N4-C catalyst of Comparative Example 1.

[0019] Figure 6 This is a STEM image of the Ni-N3-Te catalyst from Example 1.

[0020] Figure 7 The CO2RR performance of the Ni-N3-Te catalyst of Example 1 and the Ni-N4-C catalyst of Comparative Example 1 at different current densities is shown.

[0021] Figure 8 The Ni-N3-Te catalyst of Example 1 at -200 mA·cm -2 Stability test results at current density. Detailed Implementation

[0022] A typical embodiment of the present invention provides an electrocatalytic carbon dioxide reduction catalyst, comprising a carbon substrate and a diatomic active site anchored on the carbon substrate; the diatomic active site comprises a Te atom and an M atom, the Te atom and the M atom being directly connected by a chemical bond; the M atom is bonded to the carbon substrate through a nitrogen atom, and the Te atom is indirectly supported on the carbon substrate through a bond with the M atom, forming an M-N3-Te coordination configuration; wherein M is selected from one or more transition metals selected from Co, Zn, Fe, Ni, and Ti.

[0023] The provided electrocatalytic carbon dioxide catalyst, by constructing a Te-M diatomic active site and utilizing the direct bonding of Te atoms with M atoms to form an asymmetric M-N3-Te ligand field, effectively modulates the electronic structure of the active center (Te donates electrons to M, increasing the electron density of the M site). Compared to the traditional undoped Te-based M-N4 symmetric configuration, this structure significantly lowers the energy barrier of the CO2→COOH rate-determining step reaction and weakens the adsorption capacity of the active site for the H intermediate, thereby effectively suppressing the hydrogen evolution side reaction while promoting CO2 reduction activity. Simultaneously, the Te atoms are indirectly supported on the carbon substrate through bonding with M atoms, avoiding the aggregation and loss of the Te component and endowing the catalyst with the ability to operate stably for a long time at high current densities. In summary, the catalyst of this invention possesses high selectivity, high stability, and low energy consumption characteristics, and the preparation method is highly universal, showing broad application prospects in the field of CO2 electrocatalytic conversion.

[0024] The aforementioned electrocatalyst for carbon dioxide possesses a unique site structure formed through direct coordination and electronic interaction between Te atoms and transition metal M atoms. This effectively modulates the electronic structure of the active center, thereby optimizing the adsorption and conversion capabilities for CO2 reduction reaction intermediates. The catalyst with this structure utilizes Te atoms to construct an asymmetric M-N3-Te coordination field: on one hand, the electron-donating effect of Te lowers the d-band center of metal M, optimizing the *CO adsorption energy to a suitable range and reducing the *COOH formation energy barrier; on the other hand, the Te sites weakly adsorb *H, effectively suppressing the hydrogen evolution side reaction. This structure achieves improved CO Faradaic efficiency and extended stable operating time, combining low energy consumption, high selectivity, and long lifetime.

[0025] Taking transition metal Ni as an example, the reaction mechanism of Te-doped Ni-based single-atom catalyst is shown in the figure below, calculated using DFT. Figure 2As shown, a represents the undoped Ni-N4 model anchored on a carbon substrate, b represents the Te-doped Ni-N3-Te model anchored on a carbon substrate, c represents a schematic diagram of the three main steps of the catalytic conversion of CO2→CO by this catalyst, d represents the Gibbs free energy of the reaction intermediates of the two catalysts in the CO2RR process, e represents the Gibbs free energy of the reaction intermediates of the two catalysts in the HER process, and f represents the differential charge density diagram of the Ni-N3-Te catalyst. First, two coordination structures were constructed, namely, the undoped Ni-N4 model anchored on a carbon substrate (… Figure 2 a) with Te doping ( Figure 2 b) Ni-based single-atom model. Typically, the pathway for the electrocatalytic reduction of CO2 to CO involves the following four steps (see...). Figure 2 c): 1) CO2 is adsorbed onto the active site of Ni, and then gains an electron to generate *CO2. Intermediate; 2) *CO2 The intermediate receives a proton to form the *COOH intermediate; 3) The remaining -OH groups interact with protons and electrons to form H2O; 4) *CO intermediates detach from the catalyst surface.

[0026] Figure 2 d represents the Gibbs free energy of different reaction intermediates in CO2RR. Clearly, the CO2→*COOH step is the rate-determining step. Doping with Te atoms significantly reduces the free energy of this process, indicating that *COOH is more readily generated in the Ni-N3-Te model. This is because when Te forms a Ni-Te bond with Ni, the electron cloud density around Te decreases (electron loss) while the electron cloud density around Ni increases (electron gain). This suggests that when Te forms a Ni-Te bond with Ni, Te acts as an "electron donor," transferring some electrons to Ni and thus promoting the CO2RR process. See [link to details]. Figure 2 The differential charge density plot of f. Furthermore, for the HER process, the free energy for the formation of intermediate *H in the Ni-N3-Te configuration is significantly higher than that in the Ni-N4 configuration ( Figure 2 (e), thus further proving that the doping of Te can not only promote the reduction of carbon dioxide to carbon monoxide, but also inhibit the hydrogen evolution reaction.

[0027] In some preferred embodiments, the catalyst exhibits a secondary agglomerate structure, which is assembled from stacked primary particles. The primary particles are nanoparticles with a size of 10–100 nm, preferably 10–50 nm, such as 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 40 nm, or 50 nm. The morphology of the primary particles is quasi-spherical, ellipsoidal, or short rod-shaped. This multi-level structure facilitates the exposure of active sites and provides excellent mass transfer channels, synergistically achieving high current density, rapid reaction kinetics, and long-term operational reliability. Specifically, the nanoscale primary particles provide an ultra-large specific surface area, maximizing the M-N3-Te site density; the mesoporous network formed by particle stacking accelerates CO2 diffusion and CO release, while optimizing electrolyte wetting and forming efficient mass transfer channels; the stacked structure resists Ostwald ripening, the micron-sized agglomerates are easy to recover, and the regular morphology ensures electron conduction and batch consistency, improving structural stability.

[0028] In some preferred embodiments, the particle size of the secondary agglomerates is 1~8μm, for example 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, etc.

[0029] In some preferred embodiments, the primary particles adhere to each other to form interstitial channels; the pore size of the interstitial channels is 1~100nm, for example, 1nm, 3nm, 5nm, 8nm, 10nm, 15nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, etc. The 1~100nm interstitial channels formed by the adhesion of primary particles constitute a multi-level mass transfer network: mesopores accelerate CO2 diffusion and CO release, while micropores provide anchoring points with high specific surface area. The capillary effect of the channels promotes electrolyte wetting, forming an efficient three-phase reaction interface, while the rigid framework inhibits nanoparticle aggregation, ensuring high selectivity and long-term stability under high current.

[0030] In some preferred embodiments, the molar ratio of transition metal M to Te in the catalyst is 1:0.1~2, for example 1:0.1, 1:0.2, 1:0.3, 1:0.5, 1:0.8, 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, etc.

[0031] In some preferred embodiments, at least some Te atoms and at least some M atoms are dispersed on a carbon substrate in single-atom form, and at least some Te atoms pair with at least some M atoms to form Te-M diatomic active sites.

[0032] Another typical embodiment of the present invention provides a method for preparing an electrocatalytic carbon dioxide reduction catalyst, comprising: A precursor solution is prepared using organic matter containing nitrogen and carbon, a soluble transition metal salt, and a Te-containing compound as raw materials. The precursor solution undergoes a solvothermal reaction, and the resulting product is subjected to solid-liquid separation, washing, and freeze-drying to obtain a catalyst precursor. The soluble transition metal salt is a soluble salt of one or more transition metals selected from Co, Zn, Fe, Ni, and Ti. The catalyst precursor was annealed in a weak oxidizing atmosphere to obtain an electrocatalyst for carbon dioxide reduction with an M-N3-Te coordination structure; the volume fraction of oxygen in the weak oxidizing atmosphere was 0.5-1%; studies have shown that annealing in a weak oxidizing atmosphere can effectively stabilize the surface structure of the catalyst.

[0033] A one-step solvothermal in-situ carbonization method using nitrogen-containing organic compounds as the sole carbon and nitrogen source. This method eliminates the need for pre-synthesization of metal-organic frameworks or external carbon supports, avoiding interference from external templates on the active site structure, while ensuring that M and Te are in atomic proximity during the precursor stage. A combination of freeze-drying and high-temperature annealing in a weak oxidizing atmosphere is employed. Freeze-drying maintains the original proximity distribution of M and Te in the precursor after solvothermal treatment, while annealing in a weak oxidizing atmosphere causes O2 to preferentially react with unsaturated carbon atoms on the carbon substrate surface to form oxygen-containing functional groups, passivating high-energy defect sites, reducing the non-specific trapping ability of the carbon surface for Te, and forcing Te to bond with neighboring M atoms.

[0034] In some preferred embodiments, the organic compound containing both nitrogen and carbon elements is one or more of acetonitrile, dimethylformamide, formamide, ethylenediamine, and triethylamine.

[0035] In some preferred embodiments, the soluble salt of Co is selected from one or more of cobalt nitrate, cobalt acetate, cobalt nitrate hydrate, and cobalt acetate hydrate.

[0036] In some preferred embodiments, the soluble salt of Zn is selected from one or more of zinc nitrate, zinc acetate, zinc nitrate hydrate, and zinc acetate hydrate.

[0037] In some preferred embodiments, the soluble salt of Fe is selected from one or more of ferric nitrate, basic ferric acetate, and ferric acetate.

[0038] In some preferred embodiments, the soluble salt of Ni is selected from one or more of nickel nitrate, nickel acetate, nickel nitrate hydrate, and nickel acetate hydrate.

[0039] In some preferred embodiments, the soluble salt of Ti is selected from one or more of titanium nitrate and tetrabutyl titanate. In some preferred embodiments, the Te-containing compound is selected from one or more of sodium tellurite, potassium tellurite, and telluric acid.

[0040] In some preferred embodiments, the temperature of the solvothermal reaction is 150~200℃; and the time of the solvothermal reaction is 12~24h.

[0041] In some preferred embodiments, the annealing temperature is 700~900℃; the annealing time is 2~4h.

[0042] In some preferred embodiments, the solid-liquid separation is centrifugal separation. Specifically, during the centrifugal separation process, the centrifugation is carried out at a speed of 8000–10000 rpm for 10–20 minutes.

[0043] A third typical embodiment of the present invention provides a working electrode for electrocatalytic CO2 reduction, wherein the catalytically active material of the working electrode is the aforementioned electrocatalytic carbon dioxide reduction catalyst, or an electrocatalytic carbon dioxide reduction catalyst prepared by the aforementioned preparation method.

[0044] In some preferred embodiments, the substrate of the working electrode is a carbon substrate; the catalyst loading area of ​​the working electrode is 1~4 cm². 2 The catalyst loading of the working electrode is 1~2 mg·cm⁻¹. -2 .

[0045] One embodiment provides a method for preparing a working electrode for electrocatalytic CO2 reduction, comprising: mixing the aforementioned electrocatalytic CO2 reduction catalyst or the electrocatalytic CO2 catalyst prepared by the aforementioned preparation method with a binder, an alcohol solvent and deionized water, and dispersing the mixture by ultrasonication to form a uniform slurry; spraying the slurry onto a carbon paper substrate and drying it at 40~60℃ for 8~24 h to obtain an electrocatalytic CO2 reduction working electrode.

[0046] In some embodiments, the adhesive is selected from one or more of Nafion, PTFE, and PVDF.

[0047] In some embodiments, the alcohol solvent is selected from at least one of isopropanol and ethanol.

[0048] In some embodiments, the carbon paper is selected from YLS-30T, SGL-28BC, and AvCarb-MGL280.

[0049] In some embodiments, nitrogen is used as the auxiliary gas for spraying, and the gas flow rate is controlled at 1.2~3 L·min. -1 .

[0050] Some embodiments provide the application of a working electrode for electrocatalytic CO2 reduction in the electrocatalytic reduction of carbon dioxide to CO.

[0051] One approach provides a method for the electrocatalytic reduction of carbon dioxide to produce CO, including: The electrocatalytic CO2 reduction working electrode prepared by the aforementioned electrocatalytic CO2 reduction working electrode or by the aforementioned preparation method; In a gas diffusion flow electrolytic cell, using the working electrode as the working electrode, the platinum electrode as the counter electrode, and the Ag / AgCl electrode as the reference electrode, the electrocatalytic reduction of CO2 is carried out under constant current conditions, which efficiently reduces CO2 to CO and suppresses the hydrogen evolution side reaction.

[0052] In some embodiments, during the reaction, CO2 gas is emitted at a rate of 5-50 mL / min. -1 The flow rate is introduced into the cathode chamber.

[0053] In some embodiments, a concentration of 0.5~1 mol·L⁻¹ is used. -1 KHCO3 solution was used as the electrolyte, and the electrolyte flow rate was 5~20 mL·min. -1 The flow rate circulation; the current density of the electrolytic reaction is -100 to -350 mA·cm⁻¹. -2 .

[0054] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0055] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0056] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0057] All chemical reagents or raw materials used in the following steps and processes are analytical grade or battery grade.

[0058] Example 1 A method for preparing a Te-doped Ni-based single-atom catalyst for the electrocatalytic reduction of carbon dioxide includes the following steps: (1) Measure 50 mL of formamide into a beaker, then add 7 mg of nickel nitrate and mix well, then add about 5 mg of sodium tellurite, and after sonication and stirring, dissolve it completely to obtain a homogeneous solution. (2) The homogeneous solution was placed in a 100 mL polytetrafluoroethylene liner and then subjected to a solvothermal reaction in a reaction vessel at 180 °C for 12 h. (3) The slurry obtained after the reaction was centrifuged at 9000 rpm for 10 min for solid-liquid separation, and washed three times with ethanol and deionized water respectively. (4) The obtained material was then freeze-dried to obtain a precursor, and then the precursor was placed in a tube furnace and annealed at high temperature in an O2 / Ar mixed atmosphere containing 0.5% O2. The annealing temperature was 900℃. (5) After annealing, the Te-doped Ni-based single-atom catalyst (Ni-N3-Te) is obtained by grinding. (6) Prepare an electrocatalytic carbon dioxide reduction electrode using the Ni-N3-Te catalyst obtained in step (5). Take 5 mg of catalyst, then add 50 μL of 0.5 wt.% Nafion solution, 950 μL of isopropanol and deionized water in a 1:1 mixture to form a homogeneous solution. This solution is ultrasonically treated at 20-30°C for at least 1 h to ensure uniform catalyst dispersion, thus obtaining catalyst ink. Next, 500 μL of the prepared catalyst ink is uniformly sprayed onto a 2×2 cm² plate. 2 On carbon paper, the catalyst is supported on an area of ​​1×1 cm². 2 The final catalyst loading was controlled at 1 ± 0.2 mg·cm³. -2 After spraying, the resulting reduced electrode sheet is dried in a vacuum oven at 40°C for 24 hours to obtain the final working electrode.

[0059] (7) Assemble the reduction electrode, reference electrode, diaphragm, platinum electrode, gasket, and flow cell shell obtained above into a flow cell for electrocatalytic carbon dioxide reduction reaction, wherein the electrolyte is 1 mol·L⁻¹. -1 The KHCO3 electrode solution was applied at a flow rate of 10 mL / min. -1 The CO2 flow rate was 45 mL / min. -1 Subsequently, the range was -100 to -350 mA·cm. -2 The electrocatalytic carbon dioxide reduction performance was tested at a current density of -200 mA·cm⁻¹. The prepared Ni-N₃-Te catalyst exhibited performance at -200 mA·cm⁻¹. -2 At industrial-grade high current densities, its CO generation Faraday efficiency can reach about 99.5%, and it can work stably for more than 10 hours.

[0060] Comparative Example 1 (1) Follow the method of step (1) of Example 1, except that Te source is not added.

[0061] (2) The homogeneous solution was placed in a 100 mL polytetrafluoroethylene liner and then carried out a solvothermal reaction in a reaction vessel at 180 °C for 12 h. (3) The slurry obtained after the reaction was centrifuged at 9000 rpm for 10 min for solid-liquid separation, and washed three times with ethanol and deionized water respectively. (4) The obtained material is then freeze-dried to obtain a precursor. The precursor is then placed in a tube furnace and annealed at high temperature in an O2 / Ar mixed atmosphere containing 0.5% O2 at a temperature of 900°C.

[0062] (5) After annealing, the Ni-based single-atom catalyst (Ni-N4-C) is obtained by grinding.

[0063] (6) Prepare an electrocatalytic carbon dioxide reduction electrode using the Ni-N4-C catalyst obtained in step (5). Take 5 mg of catalyst, then add 50 μL of 0.5 wt.% Nafion solution, 950 μL of isopropanol and deionized water in a 1:1 mixture to form a homogeneous solution. This solution is ultrasonically treated at 20-30°C for at least 1 h to ensure uniform catalyst dispersion, thus obtaining catalyst ink. Next, 500 μL of the prepared catalyst ink is uniformly sprayed onto a 2×2 cm² plate. 2 On carbon paper, the catalyst is supported on an area of ​​1×1 cm². 2 The final catalyst loading was controlled at 1 ± 0.2 mg·cm³. -2 After spraying, the resulting reduced electrode sheet is dried in a vacuum oven at 40°C for 24 hours to obtain the final working electrode.

[0064] (7) Assemble the reduction electrode, reference electrode, diaphragm, platinum electrode, gasket, and flow cell shell obtained above into a flow cell for electrocatalytic carbon dioxide reduction reaction, wherein the electrolyte is 1 mol·L⁻¹. -1 The KHCO3 electrode solution was applied at a flow rate of 10 mL / min. -1 The CO2 flow rate was 45 mL / min. -1 Subsequently, the range was -100 to -350 mA·cm. -2 The electrocatalytic carbon dioxide reduction performance was tested at a current density of -200 mA·cm⁻¹. The prepared Ni-N₄-C catalyst was tested at this current density. -2 Under industrial-grade high current density, its CO generation Faraday efficiency can reach up to about 94.8%, and the performance degrades sharply after about 8 hours.

[0065] Using a flow cell equipped with a reduction electrode (i.e., a gas diffusion electrode (GDE)) (e.g.) Figure 3 The catalytic performance of Te-doped transition metal-based single-atom catalysts and pure transition metal-based single-atom catalysts was tested, and the devices used were as follows: Figure 3 As shown in (a), the cross-sectional view is as follows: Figure 3 As shown in (b).

[0066] The surface composition and chemical state diagrams of each element in the Ni-N3-Te sample obtained in Example 1 and the Ni-N4-C sample obtained in Comparative Example 1 were analyzed using XPS spectroscopy. The results are as follows: Figure 4 As shown. By Figure 4 The high-resolution N 1s spectrum of the Ni-N4-C catalyst shows four peaks: pyridine nitrogen (397.41 eV), Ni-N bond (398.34 eV), pyrrole nitrogen (399.79 eV), and graphitic nitrogen (402.39 eV). These four components are still observed after the introduction of Te atoms. Notably, the total nitrogen content in the material is significantly increased after Te doping. Pyridine nitrogen and pyrrole nitrogen, as the main active nitrogen species, both show a significant increase in relative content. This demonstrates that successful nitrogen doping not only increases the total amount of nitrogen atoms but also constructs a richer and more diverse range of nitrogen active sites. Figure 3 In the figure, the two main peaks of the Ni-based catalyst at binding energies of 855.08 eV and 872.39 eV correspond to Ni, respectively. 2+ 2p 3 / 2 and Ni 2+ 2p 1 / 2 This further indicates that Ni exists in atomic form rather than in nanoclusters. Furthermore, Ni can be observed in the XPS spectra of Ni from Ni-N4-C to Ni-N3-Te. 2+ 2p 3 / 2 The orbital binding energy showed a significant negative shift of 0.33 eV, indicating that the valence state of Ni atoms in Ni-N3-Te is lower. In summary, XPS data prove that Te was successfully incorporated and formed an atomically dispersed Ni-N3-Te structure; Te donated electrons to Ni, lowering the valence state of Ni, and the electron-enriched Ni sites are more conducive to CO2 activation, which is the electronic structure root of the catalyst's excellent performance.

[0067] SEM and TEM images of the Ni-N3-Te catalyst in Example 1 and the Ni-N4-C catalyst in Comparative Example 1 are shown below. Figure 5 As shown, by Figure 5 It can be seen that the two catalysts have the same morphology, both exhibiting a blocky morphology with a particle size of 1~8μm; the blocky structure is assembled from stacked small particles with a size of 10~50nm, indicating that doping does not significantly change the morphology of the catalyst.

[0068] STEM image of the Ni-N3-Te catalyst in Example 1 is shown below. Figure 6 As shown, by Figure 6As can be seen in the HAADF-STEM dark-field mode, Ni and Te elements appear as paired bright spots, indicating that both elements are highly dispersed in single-atom form without obvious aggregation. This demonstrates that M and Te are highly dispersed on the carbon substrate in single-atom pairs, verifying the existence of the diatomic active site structure. The bright spot pairs marked with red circles in the figure are typical Ni-Te dual active sites.

[0069] The CO2RR performance of the Ni-N3-Te catalyst in Example 1 and the Ni-N4-C catalyst in Comparative Example 1 at different current densities is as follows: Figure 7 As shown, by Figure 7 It can be seen that the Ni-N3-Te catalyst at 350 mA·cm -2 At high current densities, the Faraday efficiency of carbon monoxide can still be maintained above 99%, while for undoped Ni-N4-C catalysts at 250 mA·cm⁻¹, the efficiency remains above 99%. -2 At current densities, its Faraday efficiency for carbon monoxide is already below 90%.

[0070] The Ni-N3-Te catalyst of Example 1 at -200 mA·cm -2 The stability test results at current density are shown in the figure. Figure 8 As shown, by Figure 8 It can be seen that the Ni-N3-Te catalyst at 200 mA·cm -2 Even under industrial-grade high current density, its performance can still be maintained for more than 10 hours, demonstrating excellent stability.

[0071] Example 2 A method for preparing a Te-doped Co-based single-atom catalyst for the electrocatalytic reduction of carbon dioxide, comprising the following steps: (1) Measure 50 mL of formamide into a beaker, then add 7 mg of cobalt nitrate and mix well, then add about 5 mg of sodium tellurite, and after sonication and stirring, dissolve it completely to obtain a homogeneous solution. (2) The homogeneous solution was placed in a 100 mL polytetrafluoroethylene liner and then carried out a solvothermal reaction in a reaction vessel at 180 °C for 12 h. (3) The slurry obtained after the reaction was centrifuged at 9000 rpm for 10 min for solid-liquid separation, and washed three times with ethanol and deionized water respectively. (4) The obtained material is freeze-dried to obtain a precursor, and then the precursor is placed in a tube furnace and annealed at high temperature in an O2 / Ar mixed atmosphere containing 0.5% O2. The annealing temperature is 900℃.

[0072] (5) After annealing, the Te-doped Co-based single-atom catalyst (Co-N3-Te) is obtained by grinding.

[0073] (6) Prepare an electrocatalytic carbon dioxide reduction electrode using the Co-N3-Te catalyst obtained in step (5). Take 5 mg of catalyst, then add 50 μL of 0.5 wt.% Nafion solution, 950 μL of isopropanol and deionized water in a 1:1 mixture to form a homogeneous solution. This solution is ultrasonically treated at 20-30°C for at least 1 h to ensure uniform catalyst dispersion, thus obtaining catalyst ink. Next, 500 μL of the prepared catalyst ink is uniformly sprayed onto a 2×2 cm² plate. 2 On carbon paper, the catalyst is supported on an area of ​​1×1 cm². 2 The final catalyst loading was controlled at 1 ± 0.2 mg·cm³. -2 After spraying, the resulting reduced electrode sheet is dried in a vacuum oven at 40°C for 24 hours to obtain the final working electrode.

[0074] (7) Assemble the reduction electrode, reference electrode, diaphragm, platinum electrode, gasket, and flow cell shell obtained above into a flow cell for electrocatalytic carbon dioxide reduction reaction, wherein the electrolyte is 1 mol·L⁻¹. -1 The KHCO3 electrode solution was applied at a flow rate of 10 mL / min. -1 The CO2 flow rate was 45 mL / min. -1 Subsequently, the range was -100 to -350 mA·cm. -2 The electrocatalytic performance of carbon dioxide reduction was tested at a current density of -200 mA·cm⁻¹. The prepared Co-N₃-Te catalyst was tested at this current density. -2 At industrial-grade high current densities, its CO generation Faraday efficiency can reach about 98.4%, and it can work stably for more than 10 hours.

[0075] Comparative Example 2 (1) Follow the method of step (1) in Example 2, except that Te source is not added.

[0076] (2) The homogeneous solution was placed in a 100 mL polytetrafluoroethylene liner and then subjected to a solvothermal reaction in a reaction vessel at 180 °C for 12 h. (3) The slurry obtained after the reaction was centrifuged at 9000 rpm for 10 min for solid-liquid separation, and washed three times with ethanol and deionized water respectively. (4) The obtained material is freeze-dried to obtain a precursor, and then the precursor is placed in a tube furnace and annealed at high temperature in an O2 / Ar mixed atmosphere containing 0.5% O2. The annealing temperature is 900℃.

[0077] (5) After annealing, the Co-based single-atom catalyst (Co-N4-C) is obtained by grinding.

[0078] (6) Prepare an electrocatalytic carbon dioxide reduction electrode using the Co-N4-C catalyst obtained in step (5). Take 5 mg of catalyst, then add 50 μL of 0.5 wt.% Nafion solution, 950 μL of isopropanol and deionized water in a 1:1 mixture to form a homogeneous solution. This solution is ultrasonically treated at 20–30 °C for at least 1 h to ensure uniform catalyst dispersion, thus obtaining catalyst ink. Next, 500 μL of the prepared catalyst ink is uniformly sprayed onto a 2 × 2 cm plate. 2 On carbon paper, the catalyst is supported on an area of ​​1×1 cm². 2 The final catalyst loading was controlled at 1 ± 0.2 mg·cm³. -2 After spraying, the resulting reduced electrode sheet is dried in a vacuum oven at 40°C for 24 hours to obtain the final working electrode.

[0079] (7) Assemble the reduction electrode, reference electrode, diaphragm, platinum electrode, gasket, and flow cell shell obtained above into a flow cell for electrocatalytic carbon dioxide reduction reaction, wherein the electrolyte is 1 mol·L⁻¹. -1 The KHCO3 electrode solution was applied at a flow rate of 10 mL / min. -1 The CO2 flow rate was 45 mL / min. -1 Subsequently, the range was -100 to -350 mA·cm. -2 The electrocatalytic carbon dioxide reduction performance was tested at a current density of -200 mA·cm⁻¹. The prepared Co-N₄-C catalyst was tested at this current density. -2 Under industrial-grade high current density, its CO generation Faraday efficiency can reach up to about 92.1%, and the performance degrades sharply after about 6.5 hours.

[0080] Example 3 A method for preparing a Te-doped Zn-based single-atom catalyst for the electrocatalytic reduction of carbon dioxide, comprising the following steps: (1) Measure 50 mL of formamide into a beaker, then add 7 mg of zinc nitrate and mix well, then add about 5 mg of sodium tellurite, and after sonication and stirring, dissolve it completely to obtain a homogeneous solution. (2) The homogeneous solution was placed in a 100 mL polytetrafluoroethylene liner and then carried out a solvothermal reaction in a reaction vessel at 180 °C for 12 h. (3) The slurry obtained after the reaction was centrifuged at 9000 rpm for 10 min for solid-liquid separation, and washed three times with ethanol and deionized water respectively. (4) The obtained material is then freeze-dried to obtain a precursor, and then the precursor is placed in a tube furnace and annealed at high temperature in an O2 / Ar mixed atmosphere containing 0.5% O2 at a temperature of 900°C.

[0081] (5) After annealing, the Te-doped Zn-based single-atom catalyst (Zn-N3-Te) is obtained by grinding.

[0082] (6) Prepare an electrocatalytic carbon dioxide reduction electrode using the Zn-N3-Te catalyst obtained in step (5). Take 5 mg of catalyst, then add 50 μL of 0.5 wt.% Nafion solution, 950 μL of isopropanol and deionized water in a 1:1 mixture to form a homogeneous solution. This solution is ultrasonically treated at 20-30°C for at least 1 h to ensure uniform catalyst dispersion, yielding catalyst ink. Next, 500 μL of the prepared catalyst ink is uniformly sprayed onto a 2×2 cm² plate. 2 On carbon paper, the catalyst is supported on an area of ​​1×1 cm². 2 The final catalyst loading was controlled at 1 ± 0.2 mg·cm³. -2 After spraying, the resulting reduced electrode sheet is dried in a vacuum oven at 40°C for 24 hours to obtain the final working electrode.

[0083] (7) Assemble the reduction electrode, reference electrode, diaphragm, platinum electrode, gasket, and flow cell shell obtained above into a flow cell for electrocatalytic carbon dioxide reduction reaction, wherein the electrolyte is 1 mol·L⁻¹. -1 The KHCO3 electrode solution was applied at a flow rate of 10 mL / min. -1 The CO2 flow rate was 45 mL / min. -1 Subsequently, the range was -100 to -350 mA·cm. -2 The electrocatalytic carbon dioxide reduction performance was tested at a current density of -200 mA·cm⁻¹. The prepared Zn-N₃-Te catalyst was tested at this current density. -2 At industrial-grade high current density, its CO generation Faraday efficiency can reach about 97.8%, and it can work stably for more than 10 hours.

[0084] Comparative Example 3 (1) Follow the method of step (1) in Example 3, except that no Te source is added; (2) The homogeneous solution was placed in a 100 mL polytetrafluoroethylene liner and then subjected to a solvothermal reaction in a reaction vessel at 180 °C for 12 h. (3) The slurry obtained after the reaction was centrifuged at 9000 rpm for 10 min for solid-liquid separation, and washed three times with ethanol and deionized water respectively. (4) The obtained material is then freeze-dried to obtain a precursor, and then the precursor is placed in a tube furnace and annealed at high temperature in an O2 / Ar mixed atmosphere containing 0.5% O2 at a temperature of 900°C.

[0085] (5) After annealing, Zn-based single-atom catalyst (Zn-N4-C) is obtained by grinding.

[0086] (6) Prepare an electrocatalytic carbon dioxide reduction electrode using the Zn-N4-C catalyst obtained in step (5). Take 5 mg of catalyst, then add 50 μL of 0.5 wt.% Nafion solution, 950 μL of isopropanol and deionized water in a 1:1 mixture to form a homogeneous solution. This solution is ultrasonically treated at 20-30°C for at least 1 h to ensure uniform catalyst dispersion, thus obtaining catalyst ink. Next, 500 μL of the prepared catalyst ink is uniformly sprayed onto a 2×2 cm² plate. 2 On carbon paper, the catalyst is supported on an area of ​​1×1 cm². 2 The final catalyst loading was controlled at 1 ± 0.2 mg·cm³. -2 After spraying, the resulting reduced electrode sheet is dried in a vacuum oven at 40°C for 24 hours to obtain the final working electrode.

[0087] (7) Assemble the reduction electrode, reference electrode, diaphragm, platinum electrode, gasket, and flow cell shell obtained above into a flow cell for electrocatalytic carbon dioxide reduction reaction, wherein the electrolyte is 1 mol·L⁻¹. -1 The KHCO3 electrode solution was applied at a flow rate of 10 mL / min. -1 The CO2 flow rate was 45 mL / min. -1 Subsequently, the range was -100 to -350 mA·cm. -2 The electrocatalytic carbon dioxide reduction performance was tested at a current density of -200 mA·cm⁻¹. The prepared Zn-NC catalyst was tested at this current density. -2 Under industrial-grade high current density, its CO generation Faraday efficiency can reach up to about 90.4%, and the performance degrades sharply after about 6 hours.

[0088] Comparative Example 4 Example 1 was repeated, but the freeze-drying in step (4) was replaced with drying in an oven at 60°C for 12 h. XRD characterization of the resulting catalyst showed the presence of TeO2 particles. (The last part, "at -200 mA·cm," appears to be an unrelated fragment and is omitted from the translation.) -2 The CO Faraday efficiency was only 85.2%, and it rapidly declined after 2 hours. This indicates that freeze drying is crucial for the formation of M-Te bonds.

[0089] Comparative Example 5 Repeat Example 1, but change the annealing atmosphere to pure Ar (without O2). The resulting catalyst was annealed at -200 mA·cm⁻¹. -2 The CO Faraday efficiency was 88.1%, indicating poor stability. This suggests that a weak oxidizing atmosphere is indispensable for stabilizing the M-N3-Te configuration.

[0090] Analysis suggests that the significant differences in Faraday efficiency and performance retention time between Example 1 and Comparative Example 5 may be due to the following: Example 1 uses a weak oxidizing atmosphere containing 0.5% O2, which moderately oxidizes the Te precursor, promoting the formation of stable Ni-Te bonds and M-N3-Te configurations; trace amounts of O2 suppress high-temperature agglomeration of Ni / Te atoms through dynamic anchoring, maintaining atomic-level dispersion; at the same time, the weak oxidizing atmosphere preferentially reacts with unsaturated carbon atoms on the carbon substrate surface to form oxygen-containing functional groups, passivating high-energy defect sites and reducing the non-specific trapping ability of the carbon surface for Te, thereby forcing Te to bond with neighboring Ni atoms rather than forming inert Te-C or Te clusters. In Comparative Example 5, using a pure Ar inert atmosphere, Te is easily reduced to metallic Te clusters, making it difficult or less likely to form coordination bonds with Ni; Ni atoms migrate freely and easily aggregate into nanoparticles; the final product degenerates into a mixture of Ni particles and Te clusters, with the active site downgrading from a diatomic structure to low-activity Ni particles, which are more active in the hydrogen evolution reaction (H2 up to 11.8%), and the aggregation leads to extremely poor stability (<2h).

[0091] The electrochemical test results of the working electrodes prepared by the catalysts of each embodiment and comparative example in the flow cell are shown in Table 1.

[0092] Table 1. Electrochemical test results of the electrolytic flow cells for each embodiment and comparative example. As shown in Table 1, the catalysts prepared in Examples 1-3 by introducing Te-source doped transition metal-based single-atom catalysts can achieve a performance of -200 mA·cm⁻¹ when applied to carbon dioxide catalysis. -2 The catalyst catalyzes the reduction of carbon dioxide to carbon monoxide at a high current density with virtually no hydrogen production, and maintains this performance for more than 10 hours. In contrast, the carbon monoxide produced by Comparative Examples 1-3 is lower than that of the examples. Analysis suggests this is primarily due to the introduction of the Te source triggering an electron transfer process, which alters the electronic structure of the Ni species, thereby significantly enhancing the catalyst's catalytic activity and stability.

[0093] In summary, this invention successfully developed a novel, highly efficient electrocatalytic carbon dioxide reduction catalyst based on the Te-M dual-atom site design. The catalyst preparation method is simple and universally applicable. In a gas diffusion flow electrolyzer at high current densities, it exhibits high activity, high selectivity, and high stability approaching that of noble metals, demonstrating broad application prospects in the field of CO2 electrocatalytic conversion.

[0094] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An electrocatalyst for the reduction of carbon dioxide, characterized in that, It includes a carbon substrate and a diatomic active site anchored on the carbon substrate; the diatomic active site contains a Te atom and an M atom, which are directly connected by a chemical bond; the M atom is bonded to the carbon substrate through a nitrogen atom, and the Te atom is indirectly loaded on the carbon substrate through a bond with the M atom, forming an M-N3-Te coordination configuration; wherein M is selected from one or more transition metals selected from Co, Zn, Fe, Ni, and Ti.

2. The electrocatalyst for carbon dioxide reduction as described in claim 1, characterized in that, The catalyst has a secondary aggregate structure, which is assembled from the stacking of primary particles; the primary particles are nanoparticles; the size of the primary particles is 10~100nm, preferably 10~50nm; the morphology of the primary particles is spherical, ellipsoidal or short rod-shaped.

3. The electrocatalyst for carbon dioxide reduction as described in claim 2, characterized in that, The secondary agglomerates have a particle size of 1~8μm; The primary particles adhere to each other to form gap channels; the pore size of the gap channels is 1~100nm.

4. The electrocatalyst for carbon dioxide reduction as described in claim 1, characterized in that, In the catalyst, the molar ratio of transition metal M to Te is 1:0.1~2; At least some Te atoms and at least some M atoms are dispersed on a carbon substrate in the form of single atoms, and at least some Te atoms pair with at least some M atoms to form Te-M diatomic active sites.

5. A method for preparing an electrocatalyst for carbon dioxide reduction, characterized in that, include: A precursor solution is prepared using organic matter containing nitrogen and carbon, a soluble transition metal salt, and a Te-containing compound as raw materials. The precursor solution undergoes a solvothermal reaction, and the resulting product is subjected to solid-liquid separation, washing, and freeze-drying to obtain a catalyst precursor. The soluble transition metal salt is a soluble salt of one or more transition metals selected from Co, Zn, Fe, Ni, and Ti. The catalyst precursor is annealed under a weak oxidizing atmosphere to obtain an electrocatalyst for carbon dioxide reduction with an M-N3-Te coordination structure; the volume fraction of oxygen in the weak oxidizing atmosphere is 0.5-1%.

6. The method for preparing the electrocatalyst for carbon dioxide reduction as described in claim 5, characterized in that, The organic compound containing both nitrogen and carbon elements is one or more of acetonitrile, dimethylformamide, formamide, ethylenediamine, and triethylamine; The soluble salts of Co are selected from one or more of cobalt nitrate, cobalt acetate, cobalt nitrate hydrate, and cobalt acetate hydrate; The soluble salts of Zn are selected from one or more of zinc nitrate, zinc acetate, zinc nitrate hydrate, and zinc acetate hydrate; The soluble salts of Fe are selected from one or more of ferric nitrate, basic ferric acetate, and ferric acetate. The soluble salts of Ni are selected from one or more of nickel nitrate, nickel acetate, nickel nitrate hydrate, and nickel acetate hydrate; The soluble salt of Ti is selected from one or more of titanium nitrate and tetrabutyl titanate; the Te-containing compound is selected from one or more of sodium tellurite, potassium tellurite, and telluric acid.

7. The method for preparing the electrocatalyst for carbon dioxide reduction as described in claim 5, characterized in that, The temperature of the solvothermal reaction is 150~200℃; the time of the solvothermal reaction is 12~24h; And / or, the annealing temperature is 700~900℃; the annealing time is 2~4h; And / or, the solid-liquid separation is centrifugal separation.

8. A working electrode for electrocatalytic CO2 reduction, characterized in that, The catalytically active material of the working electrode is the electrocatalytic carbon dioxide reduction catalyst according to any one of claims 1 to 4, or the electrocatalytic carbon dioxide reduction catalyst prepared by the preparation method according to any one of claims 5 to 7.

9. The working electrode for electrocatalytic CO2 reduction as described in claim 8, characterized in that, The substrate of the working electrode is a carbon substrate; the catalyst loading area of ​​the working electrode is 1~4 cm². 2 The catalyst loading of the working electrode is 1~2 mg·cm⁻¹. -2 .

10. The application of the working electrode for electrocatalytic CO2 reduction as described in claim 8 or claim 9 in the electrocatalytic reduction of carbon dioxide to produce CO.

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