An alloy catalyst for electrocatalytic CO2 production, its preparation method, and its application.
By preparing CuSn alloy catalysts supported on the surface of hollow porous carbon spheres, the problems of large overpotential and poor selectivity of Cu-based electrocatalysts in CO2 conversion were solved, achieving a highly efficient CO2RR reaction, especially improving the selectivity and stability of formic acid at low temperatures.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DALIAN INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2021-12-12
- Publication Date
- 2026-06-05
AI Technical Summary
Existing Cu-based electrocatalysts suffer from problems such as large overpotential and poor selectivity for single products during CO2 conversion, which limits their application in the field of CO2 conversion.
HPC-Cu6Sn5 alloy catalyst was prepared by loading CuSn alloy catalyst onto the surface of hollow porous carbon spheres. A porous structure was formed by combining styrene, dopamine and metal source chemical methods to improve catalytic activity and selectivity.
It achieves a highly active and stable CO2RR reaction at low temperatures, improves product selectivity, especially for formic acid with a Faraday efficiency of 93%, and inhibits hydrogen production in the product.
Smart Images
Figure HDA0003405941250000011 
Figure HDA0003405941250000012 
Figure HDA0003405941250000021
Abstract
Description
Technical Field
[0001] This application relates to an alloy catalyst for electrocatalyzing CO2, its preparation method, and its application, belonging to the field of electrochemical catalysis technology. Background Technology
[0002] In recent years, the global economy has grown rapidly, and modern society's demand for energy has continued to increase. With the depletion of fossil energy reserves and the increasingly serious environmental problems, the development of alternative energy sources has become an urgent task.
[0003] To achieve carbon neutrality, the development of efficient CO2 conversion technologies is urgently needed. Electrochemical CO2 reduction can utilize electricity generated from renewable energy sources and low-cost water as a proton source to convert CO2 into high-value fuels or chemicals. If large-scale application can be achieved, it can not only reduce greenhouse gas emissions but also develop a chemical pathway independent of fossil resources. Renewable energy-driven electrochemical CO2 reduction reaction (CO2RR) is a promising technology for sustainable energy storage and atmospheric CO2 reduction. Simultaneously, the CO2RR process can provide fuels and commercial chemicals in a carbon-neutral manner. Among numerous CO2RR electrocatalysts, copper (Cu)-based materials are a unique class of CO2RR electrocatalysts capable of converting CO2 into C. 2+ High-value-added chemicals such as compounds (e.g., CH4, C2H4, and C2H5OH). However, Cu-based electrocatalysts suffer from high overpotentials and poor selectivity for single products, hindering their further application in CO2 conversion.
[0004] To address these issues, methods such as surface modification, doping, and alloying have been proposed to modulate the adsorption intensity of CO2 and its reduction intermediates at the electrode / electrolyte interface. Among these, alloy design is a promising approach for effectively tuning the performance of metal catalysts. A significant advantage of multimetallic materials is that the interaction between different metal atoms at the interface can significantly enhance catalytic activity due to geometric and electronic effects. Therefore, an increasing number of researchers are focusing on combining other metals with copper to obtain bimetallic copper-based catalysts, which can bring additional synergistic effects or stabilize reaction intermediates to improve the activity and selectivity of CO2RR. In recent years, numerous studies have reported on the synthesis of bimetallic catalysts such as CuAu, CuPd, and CuSn, demonstrating that metal alloying improves CO2RR performance. Furthermore, given the urgent need for truly active sites in the catalytic reaction process, the synthesis of modeled electrocatalysts plays a crucial guiding role in understanding the mechanism of action in the CO2RR process. Summary of the Invention
[0005] The purpose of this application is to provide a CuSn alloy catalyst that can be used for the electrocatalytic reduction of CO2, which has high activity for the electrocatalytic CO2RR reaction and adjustable product selectivity.
[0006] The purpose of this application is to provide a method for preparing an HPC-Cu6Sn5 alloy catalyst that can be used for the electrocatalytic reduction of CO2. This method is characterized by its simple operation, high reproducibility, and high versatility.
[0007] According to one aspect of this application, an alloy catalyst for electrocatalytic CO2 production is provided.
[0008] The alloy-supported catalyst comprises hollow porous carbon spheres and an alloy active component supported on the outer surface of the hollow porous carbon spheres;
[0009] The hollow porous carbon spheres have an inner diameter of 210–250 nm and an outer diameter of 280–320 nm.
[0010] The specific surface area of the hollow porous carbon spheres is 500-600 m². 2 g -1 ;
[0011] The active component of the alloy is a pure phase Cu6Sn5;
[0012] The loading of the active component in the alloy is 4.5–5.6 wt.%.
[0013] The overall morphological characteristics of the alloy-supported catalyst are that alloy nanoparticles are supported on the surface of porous hollow carbon spheres.
[0014] The hollow porous carbon sphere has a shell with micropores and mesopores; the micropores have a diameter of 0-2 nm; and the mesopores have a diameter of 2-12 nm.
[0015] According to another aspect of this application, a method for preparing the above-described alloy catalyst for electrocatalytic CO2 is provided.
[0016] At least the following steps are included:
[0017] (1) Mix raw materials containing styrene, organic acid and oxidant with water, react I, and obtain carboxyl-modified polystyrene spheres;
[0018] (2) The carboxyl-modified polystyrene spheres obtained in (1) are mixed with Tris-HCl buffer solution containing dopamine, reaction II is carried out, and polydopamine-coated carboxyl-modified polystyrene spheres are obtained.
[0019] (3) The polydopamine-coated carboxyl-modified polystyrene spheres obtained in (2) are mixed with an aqueous solution containing copper and tin sources, reaction III is carried out, and calcination is performed to obtain the alloy catalyst for electrocatalytic CO2.
[0020] In (1), the organic acid is selected from at least one of acrylic acid, methyl vinyl acid, and p-toluenesulfonic acid;
[0021] The oxidant is selected from at least one of ammonium persulfate, potassium persulfate, and sodium persulfate;
[0022] The ratio of styrene, organic acid, oxidant, and water is as follows: styrene: organic acid: oxidant: water = 15-25 ml: 0.25-0.5 g: 0.5-1.5 mmol: 100-150 ml;
[0023] The mixing includes stirring; the stirring time is 12 to 24 hours; the stirring speed is 300 to 1000 rpm;
[0024] The reaction temperature for reaction I is 50–100 °C;
[0025] The reaction time for reaction I is 12–24 h.
[0026] In (2), the dopamine is selected from Sigma-Aldrich;
[0027] The pH of the Tris-HCl buffer solution containing dopamine is 7 to 14;
[0028] The ratio of the amount of dopamine to the carboxyl-modified polystyrene spheres obtained in (1) is 0.1 / 1 to 0.5 / 1;
[0029] The temperature of reaction II is 15–25°C;
[0030] The reaction time for reaction II is 12–24 h.
[0031] (3) The copper source is selected from at least one of CuCl2, Cu(NO3)2 or CuSO4;
[0032] The tin source is selected from at least one of SnCl2 or SnCl4;
[0033] The concentration of copper in the aqueous solution containing copper and tin sources is 0–5 mmol / L; the concentration of tin is 0–5 mmol / L.
[0034] The amount of polydopamine-coated carboxyl-modified polystyrene spheres obtained in the aqueous solution (2) is 0.5 g / 100 mL to 1 g / 100 mL;
[0035] The temperature of reaction III is 15–25°C; the time of reaction III is 10–20 h.
[0036] The alloy catalyst for electrocatalytic CO2 production is subjected to vacuum drying; the vacuum degree of the vacuum drying is -1.75 to -3 MPa; the vacuum drying temperature is 50 to 80°C; and the vacuum drying time is 6 to 12 hours.
[0037] The roasting temperature is 300–900°C;
[0038] The burning time is 1 to 3 hours;
[0039] The protective atmosphere for the roasting is a nitrogen atmosphere.
[0040] The preparation method of the alloy catalyst for electrocatalytic CO2 production includes the following steps:
[0041] 1) Carboxyl-modified polystyrene spheres (PS-COOH): First, styrene (5-20 mL) is prepared using NaOH solution (50 mL, 1 mol / L). -1 The styrene, acrylic acid (0.2–1.2 g), and deionized water (50–100 mL) were extracted and placed in a three-necked flask using a mechanical stirrer. The reaction system was kept under N2 protection and then heated to 50–100 °C. 2–10 mL of APS solution (0.1 mol / L) was added. -1 The mixture was introduced into the above mixture to initiate polymerization while magnetically stirring at 300–1000 rpm. After stirring for 12–24 hours, PS-COOH spheres were obtained by centrifugation, then washed repeatedly with deionized water and ethanol several times, and then dried in a vacuum oven at 30–80°C.
[0042] 2) Polydopamine-coated polystyrene spheres (PDA@PS-COOH): At room temperature, add 1g of PS-COOH spheres to a container containing 0-5mg / mL of dopamine. -1 The polymer was deposited in a Tris-HCl buffer solution (400 ml, pH = 7–14). After polymerization for 12–24 hours, PDA@PS-COOH spheres were obtained. The product was collected after washing with deionized water and drying in a vacuum oven at 50–80 °C for 12–24 hours.
[0043] 3) Hollow carbon sphere-supported CuSn alloy material (HPC-Cu6Sn5): PDA@PS-COOH microspheres were dispersed in an aqueous solution containing 50–100 mL of 0–5 mM Cu ions and 0–5 mM Sn ions. After stirring for 10–20 hours, the mixture was centrifuged and washed 3–5 times, and then dried in a vacuum oven at 50–80 °C for 12–24 hours. The product was then collected. The obtained precursor was calcined in a tube furnace at 300–900 °C for 1–3 hours at a heating rate of 1–10 °C / min under a nitrogen atmosphere.
[0044] 4) Hollow carbon sphere-supported Cu material (HPC-Cu): PDA@PS-COOH microspheres were dispersed in an aqueous solution containing 50–100 mL of 0–5 mM Cu ions. After stirring for 10–20 hours, the mixture was centrifuged and washed 3–5 times, and then dried in a vacuum oven at 50–80 °C for 12–24 hours. The product was then collected. The obtained precursor was calcined in a tube furnace at 300–900 °C for 1–3 hours at a heating rate of 1–10 °C / min under a nitrogen atmosphere.
[0045] 5) Hollow carbon sphere supported Sn alloy material (HPC-Sn): PDA@PS-COOH microspheres were dispersed in an aqueous solution containing 50–100 mL of 0–5 mM Sn ions. After stirring for 10–20 hours, the mixture was centrifuged and washed 3–5 times, and then dried in a vacuum oven at 50–80 °C for 12–24 hours. The product was then collected. The obtained precursor was calcined in a tube furnace at 300–900 °C for 1–3 hours at a heating rate of 1–10 °C / min under a nitrogen atmosphere.
[0046] According to another aspect of this application, an electrode for electrocatalytic reduction of carbon dioxide is provided, comprising the above-described alloy catalyst for electrocatalytic CO2 or the alloy catalyst for electrocatalytic CO2 prepared by the above-described preparation method.
[0047] According to another aspect of this application, a method for preparing the above-mentioned electrode for electrocatalytic reduction of carbon dioxide is provided, comprising at least the following steps: mixing the above-mentioned alloy catalyst for electrocatalytic reduction of CO2 or the alloy catalyst for electrocatalytic reduction of CO2 prepared by the above-mentioned preparation method with isopropanol and naphthol, ultrasonically dispersing, coating on the surface of carbon paper, and drying to obtain the electrode for electrocatalytic reduction of carbon dioxide.
[0048] The mass ratio of the alloy catalyst used for electrocatalytic CO2 production to the total volume of isopropanol and naphthol is 4.5–5.5 g / L.
[0049] The volume ratio of isopropanol to naphthol is 2-3.
[0050] The ultrasonic dispersion time is 30±10 min;
[0051] The drying temperature is 60°C;
[0052] The drying time is 6–12 hours;
[0053] The loading of the alloy catalyst for electrocatalytic CO2 reduction in the electrode is 0.5 ± 0.005 mg / cm³. 2 .
[0054] According to another aspect of this application, a method for electrocatalytic reduction of CO2 is provided, wherein the electrolyte is a 0.5±0.001mol / L potassium bicarbonate solution; a three-electrode system is used, with the above as the working electrode, a platinum electrode as the counter electrode, and an Ag / AgCl electrode as the reference electrode, for electrocatalytic reduction of CO2.
[0055] The beneficial effects of this application are reflected in:
[0056] The catalyst synthesis method in this application is simple to operate and highly reproducible, which is conducive to large-scale use. The catalyst in this application is used for electrocatalytic CO2RR reaction and has high activity and stability at low temperature, i.e., low energy consumption conditions. This provides an effective solution for reducing energy consumption costs in industrial production.
[0057] 1. The catalyst preparation method provided in this application is simple to operate, reliable, and allows for catalyst modeling.
[0058] 2. The catalyst raw materials for this application are inexpensive and the preparation method is simple.
[0059] 3. This application of HPC-Cu6Sn5 catalyst to electrochemical carbon dioxide reduction reaction is novel and provides a reference for the design of future electrocatalytic CO2RR catalysts.
[0060] 4. The HPC-Cu6Sn5 catalyst prepared in this application exhibits high selectivity in the electrocatalytic reduction of carbon dioxide to formic acid, and the catalyst structure is modeled, which facilitates in-depth exploration of the catalytic mechanism. Attached Figure Description
[0061] Figure 1 The infrared spectrum of the PDA@PS-COOH microspheres prepared in Example 1 is shown.
[0062] Figure 2 The X-ray diffraction patterns are of the catalysts obtained in Example 1, Comparative Examples 1 and 2.
[0063] Figure 3 The graph shows the reaction performance evaluation of the catalyst obtained in Example 1. Reaction conditions: ambient temperature, ambient pressure, feed gas: 20 mL / min. -1CO2, 0.5M KHCO3 electrolyte.
[0064] Figure 4 The graph shows the reaction performance evaluation of the catalyst obtained in Comparative Example 1. Reaction conditions: ambient temperature, ambient pressure, feed gas: 20 mL / min. -1 CO2, 0.5M KHCO3 electrolyte.
[0065] Figure 5 The graph shows the performance evaluation of the catalyst obtained in Comparative Example 3. Reaction conditions: ambient temperature, ambient pressure, feed gas: 20 mL / min. -1 CO2, 0.5M KHCO3 electrolyte.
[0066] Figure 6 This is a TEM image of the hollow carbon spheres described in Example 1.
[0067] Figure 7 The image shows the SEM image of the catalyst obtained in Example 1. Detailed Implementation
[0068] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0069] Preparation Example 1
[0070] Polydopamine-coated polystyrene spheres (PDA@PS-COOH): At room temperature, PS-COOH spheres (1 g) were added to a solution containing dopamine (2.5 mg / mL). -1 The polymer was deposited in a Tris-HCl buffer solution (400 ml, pH = 8.5). After polymerization for 24 hours, PDA@PS-COOH spheres were obtained. The product was collected after washing with deionized water and drying in a vacuum oven at 60 °C for 12 hours.
[0071] Figure 1 Infrared spectra of the PDA@PS-COOH microspheres obtained in Example 1 were obtained. Figure 1 It can be seen that the characteristic peak of the infrared spectrum is located at 1733 cm⁻¹. -1 This indicates the presence of -COOH groups on the surface of the PS spheres, which facilitates the deposition of the PDA layer. For PDA@PS-COOH spheres, N–H / O–H tensile vibrations are observed (3600 to 310 cm⁻¹). -1 ) and C–N tensile vibration peak (1601 cm) -1 The PDA layer was successfully coated on the PS-COOH spheres.
[0072] Example 1
[0073] A hollow carbon sphere-supported CuSn alloy material (HPC-Cu6Sn5) was synthesized using a strategy combining dynamic adsorption and sacrificial templates: PDA@PS-COOH microspheres prepared in Example 1 were dispersed in an aqueous solution containing 100 mL of 2.5 mM CuCl2 and 0-5 mM SnCl2. After stirring for 10 hours, the mixture was centrifuged and washed three times, then dried in a vacuum oven at 60 °C for 12 hours, and the product was collected. The obtained precursor was calcined in a tube furnace at 600 °C for 2 hours at a heating rate of 5 °C / min under a nitrogen atmosphere. The resulting catalyst was then vacuum dried to prevent oxidation in air, thus obtaining the HPC-Cu6Sn5 catalyst.
[0074] Comparative Example 1
[0075] Hollow carbon sphere-supported Cu material (HPC-Cu) was synthesized using a strategy combining dynamic adsorption and sacrificial templates: PDA@PS-COOH microspheres were dispersed in an aqueous solution containing 100 mL of 2.5 mM Cu ions. After stirring for 10 hours, the mixture was centrifuged and washed three times, then dried in a vacuum oven at 50-80 °C for 12 hours, and the product was collected. The obtained precursor was calcined in a tube furnace at 600 °C for 2 hours at a heating rate of 5 °C / min under a nitrogen atmosphere. The resulting catalyst was then vacuum dried to prevent oxidation in air, thus obtaining the HPC-Cu catalyst.
[0076] Comparative Example 2
[0077] Hollow carbon sphere-supported Sn material (HPC-Sn) was synthesized using a combination of dynamic adsorption and sacrificial template strategy: PDA@PS-COOH microspheres were dispersed in an aqueous solution containing 100 mL of 2.5 mM Sn ions. After stirring for 10 hours, the mixture was centrifuged and washed three times, then dried in a vacuum oven at 60 °C for 12 hours, and the product was collected. The obtained precursor was calcined in a tube furnace at 600 °C for 2 hours at a heating rate of 5 °C / min under a nitrogen atmosphere. The resulting catalyst was then vacuum dried to prevent oxidation in air, thus obtaining the HPC-Sn catalyst.
[0078] Characterization Example 1
[0079] The catalysts obtained in Example 1, Comparative Example 1, and Comparative Example 2 were subjected to X-ray diffraction tests.
[0080] Figure 2 The images show the X-ray diffraction patterns of the catalysts prepared in Examples 1, 1, and 2. Figure 2 It can be seen that HPC-Cu shows the characteristic peaks of Cu and Cu2O; HPC-Cu6Sn5 shows the characteristic peaks of Cu6Sn5; and HPC-Sn shows the characteristic peaks of Sn.
[0081] Characterization Example 2
[0082] The catalyst obtained in Example 1 was subjected to SEM testing.
[0083] Figure 6 This is a SEM image of the catalyst obtained in Example 1. Figure 6 It can be seen that the HPC-Cu6Sn5 catalyst has a nanosphere microstructure, and Cu6Sn5 is distributed in an island-like pattern on the surface of the microsphere.
[0084] Test Example 1
[0085] Cyclic voltammetry was first performed in a 0.5 mol / L KHCO3 solution under a CO2 atmosphere at a scan rate of 100 mV·s. -1 The scan range was -2.0 to 0 V (vs. RHE), with 20 scan cycles. This step cleans the catalyst surface and activates it. Subsequently, polarization curves were measured under carbon dioxide and nitrogen atmospheres to characterize the catalyst's electrocatalytic performance, with a scan rate of 10 mV·s. -1 The scanning range was -2.0 to 0 V. A constant voltage test was then performed under a carbon dioxide atmosphere. The raw gas and gaseous products were analyzed online using an Agilent 7890B gas chromatograph equipped with TCD and FID detectors; the collected liquid products were detected using NMR. For the above scanning range, a calomel electrode was selected as the reference electrode, and a Pt sheet as the counter electrode.
[0086] Figure 3 The graph shows the reaction performance evaluation of the catalyst obtained in Example 1. Reaction conditions: ambient temperature, ambient pressure, feed gas: 20 mL / min. -1 CO2, 0.5M KHCO3 electrolyte.
[0087] Figure 4 The graph shows the reaction performance evaluation of the catalyst obtained in Comparative Example 1. Reaction conditions: ambient temperature, ambient pressure, feed gas: 20 mL / min. -1 CO2, 0.5M KHCO3 electrolyte.
[0088] Figure 5 The graph shows the performance evaluation of the catalyst obtained in Comparative Example 3. Reaction conditions: ambient temperature, ambient pressure, feed gas: 20 mL / min. -1 CO2, 0.5M KHCO3 electrolyte.
[0089] Depend on Figure 3 It can be seen that the selectivity of the HPC-Cu6Sn5 catalyst for formic acid products first increases and then decreases with changes in the applied potential. The highest formic acid selectivity is observed at an applied potential of -1.1V.
[0090] Depend on Figure 4 It can be seen that the HPC-Cu catalyst exhibits a multi-product distribution characteristic as the applied potential changes with the product selectivity.
[0091] Depend on Figure 5 It can be seen that the selectivity of the HPC-Sn catalyst for formic acid products first increases and then decreases with changes in the applied potential. The highest formic acid selectivity is observed at an applied potential of -1.3V.
[0092] Compared with HPC-Cu and HPC-Sn catalysts, the HPC-Cu6Sn5 catalyst exhibits excellent formic acid selectivity, achieving a Faradaic efficiency of ~93% for formic acid at a potential of -1.1V vs RHE. Moreover, with the formation of the Cu6Sn5 alloy phase, hydrogen production in the product is significantly suppressed compared to the HPC-Sn catalyst, further promoting the conversion of CO2 to HCOOH.
[0093] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. An alloy-supported catalyst for electrocatalytic CO2 production, characterized in that, The alloy-supported catalyst comprises hollow porous carbon spheres and an alloy active component supported on the outer surface of the hollow porous carbon spheres; The hollow porous carbon spheres have an inner diameter of 210~250 nm and an outer diameter of 280~320 nm. The specific surface area of the hollow porous carbon spheres is 500~600 m². 2 g -1 ; The active component of the alloy is a pure phase Cu6Sn5; The loading of the active component in the alloy is 4.5~5.6 wt.%. The overall morphological characteristics of the alloy-supported catalyst are that alloy nanoparticles are supported on the surface of hollow porous carbon spheres.
2. The alloy-supported catalyst for electrocatalytic CO2 production according to claim 1, characterized in that, The hollow porous carbon sphere has a shell with micropores and mesopores; the micropores have a diameter of 0~2 nm; and the mesopores have a diameter of 2~12 nm.
3. A method for preparing an alloy-supported catalyst for electrocatalytic CO2 as described in claim 1 or 2, characterized in that, At least the following steps are included: (1) Mix the raw materials containing styrene, organic acid and oxidant with water, react I, and obtain carboxyl-modified polystyrene spheres; (2) The carboxyl-modified polystyrene spheres obtained in (1) are mixed with Tris-HCl buffer solution containing dopamine, reaction II is carried out, and polydopamine-coated carboxyl-modified polystyrene spheres are obtained. (3) The polydopamine-coated carboxyl-modified polystyrene spheres obtained in (2) are mixed with an aqueous solution containing copper and tin sources, reaction III is carried out, and calcination is performed to obtain the alloy catalyst for electrocatalytic CO2.
4. The preparation method according to claim 3, characterized in that, In (1), the organic acid is selected from at least one of acrylic acid, methyl vinyl acid, and p-toluenesulfonic acid; The oxidant is selected from at least one of ammonium persulfate, potassium persulfate, and sodium persulfate; The ratio of styrene, organic acid, oxidant, and water is as follows: styrene: organic acid: oxidant: water = 15~25ml: 0.25~0.5g: 0.5~1.5mmol: 100~150ml; The mixing includes stirring; the stirring time is 12-24 hours; the stirring speed is 300-1000 rpm; The reaction temperature for reaction I is 50~100℃; The reaction time for reaction I is 12-24 hours.
5. The preparation method according to claim 3, characterized in that, In (2), the dopamine is selected from Sigma-Aldrich; The pH of the Tris-HCl buffer solution containing dopamine is 7-14; The ratio of the amount of dopamine to the carboxyl-modified polystyrene spheres obtained in (1) is 0.1 / 1 to 0.5 / 1; The temperature of reaction II is 15~25℃; The reaction time for reaction II is 12-24 h.
6. The preparation method according to claim 3, characterized in that, (3) wherein the copper source is selected from at least one of CuCl2, Cu(NO3)2 or CuSO4; The tin source is selected from at least one of SnCl2 or SnCl4; The concentration of copper in the aqueous solution containing copper and tin sources is 0-5 mmol / L; the concentration of tin is 0-5 mmol / L. The amount of polydopamine-coated carboxyl-modified polystyrene spheres obtained in the aqueous solution (2) is 0.5 g / 100 mL to 1 g / 100 mL.
7. The preparation method according to claim 3, characterized in that, (3) The temperature of reaction III is 15~25℃; the time of reaction III is 10~20 h; The alloy catalyst for electrocatalytic CO2 production is subjected to vacuum drying; the vacuum degree of the vacuum drying is -1.75 to -3 MPa; the vacuum drying temperature is 50 to 80°C; and the vacuum drying time is 6 to 12 hours. The roasting temperature is 300~900℃; The burning time is 1-3 hours; The protective atmosphere for the roasting is a nitrogen atmosphere.
8. An electrode for the electrocatalytic reduction of carbon dioxide, characterized in that, Includes the alloy catalyst for electrocatalytic CO2 as described in claim 1 or 2, or the alloy catalyst for electrocatalytic CO2 prepared by the preparation method described in any one of claims 3 to 7.
9. A method for preparing an electrode for electrocatalytic reduction of CO2 as described in claim 8, characterized in that, The process includes at least the following steps: mixing the alloy catalyst for electrocatalytic CO2 as described in claim 1 or 2, or the alloy catalyst for electrocatalytic CO2 prepared by any one of the preparation methods described in claims 3 to 7, with isopropanol and naphthol, ultrasonically dispersing, coating on the surface of carbon paper, and drying to obtain the electrode for electrocatalytic reduction of carbon dioxide. The mass ratio of the alloy catalyst used for electrocatalytic CO2 production to the total volume of isopropanol and naphthol is 4.5~5.5 g / L. The volume ratio of isopropanol to naphthol is 12-24; The ultrasonic dispersion time is 30±10 min; The drying temperature is 50~80℃; The drying time is 5-10 minutes; The loading of the alloy catalyst for electrocatalytic CO2 reduction in the electrode is 0.5 ± 0.005 mg / cm³. 2 .
10. A method for electrocatalytic reduction of CO2, characterized in that, The electrolyte is a 0.5±0.001 mol / L potassium bicarbonate solution; a three-electrode system is used, with the electrode prepared according to claim 9 for electrocatalytic reduction of carbon dioxide as the working electrode, a platinum electrode as the counter electrode, and an Ag / AgCl electrode as the reference electrode for electrocatalytic reduction of CO2.