Preparation method and application of carambola-shaped CuO / Cu-MOF electrocatalyst

Abstract

The invention discloses a preparation method and application of a carambola-shaped CuO / Cu-MOF electrocatalyst, and relates to a preparation method and application of an electrocatalyst. The invention aims to solve the problem that the C2H4 selectivity of the existing CuO is limited. The method comprises the following steps: 1, preparing a precursor solution; 2, hydrothermal reaction; 3, roasting; and 4, in-situ transformation. The application is as follows: the carambola-shaped CuO / Cu-MOF electrocatalyst is used as a raw material to prepare a gas diffusion electrode for electrocatalytic CO2 reduction. The preparation method is used for preparation and application of the carambola-shaped CuO / Cu-MOF electrocatalyst.

Description

Technical Field

[0001] The invention relates to a preparation method and application of an electrocatalyst. Background Art

[0002] Electrocatalytic CO 2 Reduction technology uses electrochemical reaction to 2 It can be converted into valuable chemicals and energy (such as methane, ethylene, methanol, etc.), effectively recycling carbon dioxide. The process can be directly driven by renewable electricity (such as wind power and solar energy), avoiding carbon emissions caused by traditional fossil energy.

[0003] Metal oxide materials have broad application prospects in the field of electrocatalysis, especially in CO 2 The catalytic performance can be optimized by changing the surface morphology, lattice defects or doping of metal oxides. Cu is the only known 2 Restore to C 2 The electrocatalyst of the product, CuO in CO 2 The reduction of single metal oxides C 2 H 4 The selectivity is still limited. Summary of the invention

[0004] The present invention aims to solve the problem of the existing CuO 2 H 4 The problem of limited selectivity is solved, and a preparation method and application of a carambola-shaped CuO / Cu-MOF electrocatalyst are provided.

[0005] A method for preparing a carambola-shaped CuO / Cu-MOF electrocatalyst is carried out according to the following steps:

[0006] 1. Preparation of precursor solution:

[0007] Under stirring conditions, copper salt is added into water to dissolve to obtain a copper salt solution, and then under stirring conditions, a precipitant is added into the copper salt solution and mixed evenly, and finally under room temperature, the reaction is stirred for 5 minutes to 80 minutes to obtain a precursor solution;

[0008] 2. Hydrothermal reaction:

[0009] The precursor solution is subjected to a hydrothermal reaction, then cooled to room temperature, and finally separated, washed and dried in sequence to obtain a precursor;

[0010] 3. Roasting:

[0011] The precursor is calcined for 1 h to 4 h in an air or oxygen atmosphere at a temperature of 200° C. to 600° C. to obtain a precursor CuO;

[0012] 4. In situ transformation:

[0013] The precursor CuO is added to a mixed solution of an organic solvent and water to dissolve, and then trimesic acid is added and stirred for 10 to 60 minutes. Finally, a hydrothermal reaction is carried out at a temperature of 100°C to 180°C for 12 to 36 hours to obtain a carambola-shaped CuO / Cu-MOF electrocatalyst.

[0014] Application of a carambola-shaped CuO / Cu-MOF electrocatalyst, the carambola-shaped CuO / Cu-MOF electrocatalyst is used as a raw material to prepare a gas diffusion electrode for electrocatalysis of CO 2 reduction.

[0015] The beneficial effects of the present invention are:

[0016] The carambola-shaped CuO / Cu-MOF electrocatalyst prepared by the present invention exhibits excellent electrocatalytic CO 2 Reduction performance: when the addition ratio of the prepared CuO precursor to trimesic acid is 3:1 and the activation time is 20 min, the working current density is 300 mA cm -2 Lower C 2 H 4 The selectivity reached 48%.

[0017] The carambola-shaped CuO / Cu-MOF electrocatalyst prepared by the present invention has a simple process, good scalability, and can be produced on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 XRD images of the CuO precursor prepared in step 3 of Example 1 and the star fruit-shaped CuO / Cu-MOF electrocatalyst prepared in step 4;

[0019] Figure 2 This is a scanning electron microscope image of the carambola-shaped CuO / Cu-MOF electrocatalyst prepared in Example 1;

[0020] Figure 3 The carambola-shaped CuO / Cu-MOF electrocatalyst CO prepared in Example 1 2 The selectivity of the reduction products varies with the applied current density. DETAILED DESCRIPTION

[0021] Specific implementation method 1: This implementation method is a method for preparing a carambola-shaped CuO / Cu-MOF electrocatalyst, which is carried out according to the following steps:

[0022] 1. Preparation of precursor solution:

[0023] Under stirring conditions, copper salt is added into water to dissolve to obtain a copper salt solution, and then under stirring conditions, a precipitant is added into the copper salt solution and mixed evenly, and finally under room temperature, the reaction is stirred for 5 minutes to 80 minutes to obtain a precursor solution;

[0024] 2. Hydrothermal reaction:

[0025] The precursor solution is subjected to a hydrothermal reaction, then cooled to room temperature, and finally separated, washed and dried in sequence to obtain a precursor;

[0026] 3. Roasting:

[0027] The precursor is calcined for 1 h to 4 h in an air or oxygen atmosphere at a temperature of 200° C. to 600° C. to obtain a precursor CuO;

[0028] 4. In situ transformation:

[0029] The precursor CuO is added to a mixed solution of an organic solvent and water to dissolve, and then trimesic acid is added and stirred for 10 to 60 minutes. Finally, a hydrothermal reaction is carried out at a temperature of 100°C to 180°C for 12 to 36 hours to obtain a carambola-shaped CuO / Cu-MOF electrocatalyst.

[0030] This specific embodiment combines metal oxides with organic materials to form an organic-inorganic hybrid catalyst. CuO / Cu-MOF has a highly adjustable pore structure and abundant coordination active sites. Cu-MOF materials provide abundant reaction sites, optimizing CO 2 By combining CuO with Cu-MOF, the catalyst CO 2 Reduction selectivity.

[0031] The beneficial effects of this embodiment are:

[0032] The carambola-shaped CuO / Cu-MOF electrocatalyst prepared in this embodiment exhibits excellent electrocatalytic CO 2 Reduction performance: when the addition ratio of the prepared CuO precursor to trimesic acid is 3:1 and the activation time is 20 min, the working current density is 300 mA cm -2 Lower C 2 H 4 The selectivity reached 48%.

[0033] The carambola-shaped CuO / Cu-MOF electrocatalyst prepared in this embodiment has a simple process, good scalability, and can be mass-produced.

[0034] Specific embodiment 2: This embodiment is different from specific embodiment 1 in that: the copper salt described in step 1 is copper nitrate, copper chloride, copper sulfate or copper acetate; the precipitant described in step 1 is urea, sodium carbonate, sodium hydroxide, potassium hydroxide or hexamethylenetetramine. Others are the same as specific embodiment 1.

[0035] Specific implementation method three: This implementation method is different from specific implementation method one or two in that: in step one, under the condition of stirring speed of 200r / min to 2000r / min, copper salt is added to water to dissolve to obtain copper salt solution, and then under the condition of stirring speed of 200r / min to 2000r / min, precipitant is added to the copper salt solution and mixed evenly, and finally under the condition of room temperature and stirring speed of 200r / min to 2000r / min, stirring reaction is carried out for 5min to 80min to obtain precursor solution; the stirring speed described in step four is 200r / min to 2000r / min. Others are the same as specific implementation method one or two.

[0036] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that: the concentration of the copper salt in the copper salt solution in step 1 is 1 mM to 1 M; the molar ratio of the copper salt to the precipitant in step 1 is 1:(1 to 10). The rest is the same as specific embodiment 3.

[0037] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that the hydrothermal reaction in step 2 is carried out at a temperature of 100° C. to 180° C. for 12 h to 36 h. The rest is the same as specific embodiments 1 to 4.

[0038] Specific embodiment 6: This embodiment is different from specific embodiments 1 to 5 in that the separation, washing and drying described in step 2 are specifically carried out according to the following steps: centrifuging for 2 min to 10 min at a rotation speed of 4000 rpm to 9000 rpm to obtain particles, then washing the particles to neutrality using anhydrous ethanol and water as washing liquid, and finally drying the washed particles for 12 h to 24 h at a temperature of 40 ° C to 100 ° C. The rest is the same as specific embodiments 1 to 5.

[0039] Specific embodiment 7: This embodiment differs from specific embodiments 1 to 6 in that: the mass ratio of the precursor CuO described in step 4 to the mixed solution of organic solvent and water is 1g:(150-400)mL; the molar ratio of the precursor CuO described in step 4 to trimesic acid is (1-5):1; the volume ratio of the organic solvent to water in the mixed solution of organic solvent and water described in step 4 is 1:(0.1-10), and the organic solvent is methanol, ethanol, propanol or isopropanol. The rest is the same as specific embodiments 1 to 6.

[0040] Specific embodiment 8: This embodiment uses a carambola-shaped CuO / Cu-MOF electrocatalyst, which is used as a raw material to prepare a gas diffusion electrode for electrocatalysis of CO 2 reduction.

[0041] Specific embodiment 9: This embodiment is different from specific embodiment 8 in that: the gas diffusion electrode is prepared according to the following steps:

[0042] ① Add the carambola-shaped CuO / Cu-MOF electrocatalyst to a mixed solution of Nafion and isopropanol, and mix them ultrasonically for 10 min to 60 min at a power of 100 W to 500 W to obtain a catalyst ink;

[0043] The volume ratio of Nafion solution to isopropanol in the mixed solution of Nafion and isopropanol is 1:(10-30); the concentration of the carambola-shaped CuO / Cu-MOF electrocatalyst in the catalyst ink is 3 mg / mL-10 mg / mL;

[0044] ② According to the loading amount of carambola-shaped CuO / Cu-MOF electrocatalyst is 0.5 mg / cm 2 ~2.0mg / cm 2 , under the condition of temperature of 35°C to 65°C, the catalyst ink is sprayed onto the carbon paper, and finally dried to obtain a gas diffusion electrode. The rest is the same as the eighth embodiment.

[0045] The preparation of the gas diffusion electrode in this embodiment is simple to operate, the star fruit-shaped CuO / Cu-MOF electrocatalyst does not need to be pretreated, and CuO / Cu-MOF as an organic-inorganic interface material of a stable oxide and a stable MOF exists stably in an air atmosphere, and there is no need to consider the problem of air oxidation.

[0046] Specific embodiment 10: This embodiment is different from either specific embodiment 8 or 9 in that: the electrocatalytic CO 2 The restoration is carried out according to the following steps:

[0047] ①Assembly: Using a flow-type electrolyzer, 2 A gas diffusion electrode is arranged between the gas flow chamber and the cathode chamber, and an anion exchange membrane is arranged between the cathode chamber and the anode chamber; a counter electrode is arranged in the anode chamber, a reference electrode is arranged in the cathode chamber, and a cathode liquid flow cell is connected to the cathode chamber through a conduit, and an anode liquid flow cell is connected to the anode chamber through a conduit, and an electrolyte is poured into the cathode liquid flow cell and the anode liquid flow cell, and finally a positive electrode of a power supply is connected to the counter electrode, and a negative electrode of a power supply is connected to the gas diffusion electrode;

[0048] ②Electrocatalytic activation: At a flow rate of 1mL / min to 50mL / min, CO 2 Gas into CO 2 Gas flow chamber, maintain CO 2 The catalyst is activated for 5 to 60 minutes under the condition that the potential applied to the gas diffusion electrode is -1.0 V to -3.0 V vsAg / AgCl.

[0049] ③Electrocatalytic CO 2 Reduction: At a flow rate of 1 mL / min to 50 mL / min, 2 Gas into CO 2 Gas flow chamber, maintain CO 2 The current density of the gas diffusion electrode was 50 mA cm -2 ~900mA·cm -2 Under the conditions of electrocatalytic CO 2 Reduction, collection of gas products, separation and purification of the electrolyte after the reaction, and the completion of electrocatalytic CO 2 reduction;

[0050] The electrolyte described in step ① is a KOH electrolyte with a concentration of 0.5M to 5M; the CO 2 The gas flow chamber is made of stainless steel; the counter electrode described in step ① is Ni foam, Pt-plated titanium felt or IrO-plated 2 Titanium felt; the reference electrode in step ① is an Ag / AgCl electrode. The rest is the same as the eighth or ninth embodiment.

[0051] The following examples are used to verify the beneficial effects of the present invention:

[0052] Embodiment 1:

[0053] A method for preparing a carambola-shaped CuO / Cu-MOF electrocatalyst is carried out according to the following steps:

[0054] 1. Preparation of precursor solution:

[0055] Under the condition of stirring at a speed of 800 r / min, copper salt is added into water to dissolve to obtain a copper salt solution, and then under the condition of stirring at a speed of 800 r / min, a precipitant is added into the copper salt solution and mixed evenly, and finally under the condition of room temperature and stirring at a speed of 800 r / min, the reaction is stirred for 20 minutes to obtain a precursor solution;

[0056] 2. Hydrothermal reaction:

[0057] Under the condition of temperature of 100° C., the precursor solution is subjected to hydrothermal reaction for 12 hours, then cooled to room temperature, and finally separated, washed and dried in sequence to obtain a precursor;

[0058] 3. Roasting:

[0059] The precursor was calcined for 3 h in an air atmosphere at 300 °C to obtain a precursor CuO;

[0060] 4. In situ transformation:

[0061] The precursor CuO was added to a mixed solution of organic solvent and water to dissolve, and then trimesic acid was added. The mixture was stirred for 30 minutes at a stirring speed of 800 r / min. Finally, the mixture was hydrothermally reacted at a temperature of 120°C for 24 hours to obtain a carambola-shaped CuO / Cu-MOF electrocatalyst.

[0062] The copper salt described in step 1 is copper chloride; the precipitant described in step 1 is sodium hydroxide.

[0063] The concentration of copper salt in the copper salt solution described in step 1 is 5 mM; the molar ratio of the copper salt described in step 1 to the precipitant is 1:1.

[0064] The separation, washing and drying described in step 2 are specifically carried out according to the following steps: centrifuge for 2 minutes at a rotation speed of 4000 rpm to obtain particles, then use anhydrous ethanol and water as washing liquid to wash the particles until they are neutral, and finally dry the washed particles at a temperature of 60°C for 12 hours.

[0065] The mass ratio of the precursor CuO described in step 4 to the volume ratio of the mixed solution of organic solvent and water is 1g:280mL; the molar ratio of the precursor CuO described in step 4 to trimesic acid is 3:1; the volume ratio of the organic solvent to water in the mixed solution of organic solvent and water described in step 4 is 1:1, and the organic solvent is ethanol.

[0066] Application of the prepared carambola-shaped CuO / Cu-MOF electrocatalyst nanocatalyst. The carambola-shaped CuO / Cu-MOF electrocatalyst is used as a raw material to prepare a gas diffusion electrode for electrocatalytic CO 2 reduction;

[0067] The gas diffusion electrode is specifically prepared according to the following steps:

[0068] ① Add the carambola-shaped CuO / Cu-MOF electrocatalyst to a mixed solution of Nafion and isopropanol, and mix them ultrasonically for 20 minutes at a power of 300 W to obtain a catalyst ink;

[0069] The volume ratio of Nafion solution to isopropanol in the mixed solution of Nafion and isopropanol is 1:30; the concentration of the carambola-shaped CuO / Cu-MOF electrocatalyst in the catalyst ink is 8 mg / mL;

[0070] ② According to the loading amount of carambola-shaped CuO / Cu-MOF electrocatalyst is 1.0 mg / cm 2 , spraying the catalyst ink onto carbon paper at a temperature of 55°C, and finally drying to obtain a gas diffusion electrode;

[0071] The carbon paper is 28BC;

[0072] The electrocatalytic CO 2 The restoration is carried out according to the following steps:

[0073] ①Assembly: Using a flow-type electrolyzer, 2 A gas diffusion electrode is arranged between the gas flow chamber and the cathode chamber, and an anion exchange membrane is arranged between the cathode chamber and the anode chamber; a counter electrode is arranged in the anode chamber, a reference electrode is arranged in the cathode chamber, and a cathode liquid flow cell is connected to the cathode chamber through a conduit, and an anode liquid flow cell is connected to the anode chamber through a conduit, and an electrolyte is poured into the cathode liquid flow cell and the anode liquid flow cell, and finally a positive electrode of a power supply is connected to the counter electrode, and a negative electrode of a power supply is connected to the gas diffusion electrode;

[0074] The electrolyte is a KOH electrolyte with a concentration of 1M; the CO 2 The material of the gas flow chamber is stainless steel; the counter electrode described in step ① is foamed Ni; the reference electrode is an Ag / AgCl electrode; the anion exchange membrane is fumasep FAA-3-PK-130;

[0075] ②Electrocatalytic activation: CO 2 Gas into CO 2 Gas flow chamber, maintain CO 2 The catalyst was activated for 20 min under the condition of continuous flow and the potential applied to the gas diffusion electrode was -2.0 V vs Ag / AgCl.

[0076] ③Electrocatalytic CO 2Reduction: CO 2 Gas into CO 2 Gas flow chamber, maintain CO 2 The current density of the gas diffusion electrode was 50 mA cm -2 ~500mA·cm -2 Under the conditions of electrocatalytic CO 2 Reduction, collection of gas products, separation and purification of the electrolyte after the reaction, and the completion of electrocatalytic CO 2 reduction.

[0077] Example 2: This example is different from Example 1 in that the molar ratio of the copper salt to the precipitant in step 1 is 1:3. Others are the same as Example 1.

[0078] Embodiment 3: This embodiment is different from Embodiment 1 in that the organic solvent in step 4 is methanol. The rest is the same as Embodiment 1.

[0079] Embodiment 4: This embodiment is different from Embodiment 1 in that the volume ratio of the organic solvent to water in the mixed solution of the organic solvent and water in step 4 is 1:3. The rest is the same as Embodiment 1.

[0080] Embodiment 5: This embodiment is different from Embodiment 1 in that the molar ratio of trimesic acid to the precursor CuO in step 4 is 5:1. The rest is the same as Embodiment 1.

[0081] Figure 1 XRD images of the precursor CuO prepared in step 3 of Example 1 and the carambola-shaped CuO / Cu-MOF electrocatalyst prepared in step 4; it can be seen from the figure that the system without trimesic acid only shows the relevant diffraction peaks of CuO. The system with trimesic acid shows the relevant diffraction peaks of Cu-MOF in addition to the relevant diffraction peaks of CuO, indicating that CuO / Cu-MOF is formed after the addition of trimesic acid.

[0082] Figure 2 This is a scanning electron microscope image of the carambola-shaped CuO / Cu-MOF electrocatalyst prepared in Example 1; as can be seen from the figure, the prepared CuO / Cu-MOF has a carambola-like morphology.

[0083] Figure 3 The carambola-shaped CuO / Cu-MOF electrocatalyst CO prepared in Example 1 2 The selectivity of reduction products varies with the applied current density. As shown in the figure, as the applied current density gradually increases, the CuO / Cu-MOF nanocatalyst is the electrocatalytic CO 2 The main product of reduction is C 2 H4 , in CO 2 In the gas phase products of the reduction reaction, at a lower current density (<150 mA / cm 2 ) 2 H 4 The selectivity is lower than that at high current density (150mA / cm 2 ~500mA / cm 2 ) 2 H 4 Selectivity, at 300mA / cm 2 According to the relevant CO 2 Study on the reaction mechanism of reduction reaction: the *CO molecules adsorbed on the Cu surface form C 2 H 4 As the current density increases, the CO selectivity decreases, which means that more *CO undergoes CC coupling to form C 2 H 4 At the same time, as the current density gradually increases, H 2 The selectivity shows a trend of decreasing first and then increasing, indicating that at high current density, it is not conducive to C 2 H 4 form.

Claims

1. A method for preparing a carambola-shaped CuO / Cu-MOF electrocatalyst, characterized in that It is carried out in the following steps:

1. Preparation of precursor solution: Under stirring conditions, copper salt is added into water to dissolve to obtain a copper salt solution, and then under stirring conditions, a precipitant is added into the copper salt solution and mixed evenly, and finally under room temperature, the reaction is stirred for 5 minutes to 80 minutes to obtain a precursor solution; 2. Hydrothermal reaction: The precursor solution is subjected to a hydrothermal reaction, then cooled to room temperature, and finally separated, washed and dried in sequence to obtain a precursor; 3. Roasting: The precursor is calcined for 1 h to 4 h in an air or oxygen atmosphere at a temperature of 200° C. to 600° C. to obtain a precursor CuO; 4. In situ transformation: The precursor CuO is added to a mixed solution of an organic solvent and water to dissolve, and then trimesic acid is added and stirred for 10 to 60 minutes. Finally, a hydrothermal reaction is carried out at a temperature of 100°C to 180°C for 12 to 36 hours to obtain a carambola-shaped CuO / Cu-MOF electrocatalyst.

2. The method for preparing a carambola-shaped CuO / Cu-MOF electrocatalyst according to claim 1, characterized in that The copper salt described in step 1 is copper nitrate, copper chloride, copper sulfate or copper acetate; the precipitant described in step 1 is urea, sodium carbonate, sodium hydroxide, potassium hydroxide or hexamethylenetetramine.

3. The method for preparing a carambola-shaped CuO / Cu-MOF electrocatalyst according to claim 1, characterized in that In step 1, a copper salt is added to water and dissolved at a stirring speed of 200 r / min to 2000 r / min to obtain a copper salt solution, and then a precipitant is added to the copper salt solution and mixed evenly at a stirring speed of 200 r / min to 2000 r / min. Finally, the reaction is stirred for 5 min to 80 min at room temperature and a stirring speed of 200 r / min to 2000 r / min to obtain a precursor solution; The stirring speed described in step 4 is 200r / min~2000r / min.

4. The method for preparing a carambola-shaped CuO / Cu-MOF electrocatalyst according to claim 1, characterized in that The concentration of the copper salt in the copper salt solution described in step 1 is 1 mM to 1 M; the molar ratio of the copper salt to the precipitant described in step 1 is 1:(1 to 10).

5. The method for preparing a carambola-shaped CuO / Cu-MOF electrocatalyst according to claim 1, characterized in that The hydrothermal reaction in step 2 is specifically carried out at a temperature of 100° C. to 180° C. for 12 h to 36 h.

6. The method for preparing a carambola-shaped CuO / Cu-MOF electrocatalyst according to claim 1, characterized in that The separation, washing and drying described in step 2 are specifically carried out according to the following steps: centrifuge for 2min to 10min at a rotation speed of 4000rpm to 9000rpm to obtain particles, then use anhydrous ethanol and water as washing liquid to wash the particles until they are neutral, and finally dry the washed particles at a temperature of 40℃ to 100℃ for 12h to 24h.

7. The method for preparing a carambola-shaped CuO / Cu-MOF electrocatalyst according to claim 1, characterized in that The mass ratio of the precursor CuO described in step 4 to the volume ratio of the mixed solution of organic solvent and water is 1g:(150-400)mL; the molar ratio of the precursor CuO described in step 4 to trimesic acid is (1-5):1; the volume ratio of the organic solvent to water in the mixed solution of organic solvent and water described in step 4 is 1:(0.1-10), and the organic solvent is methanol, ethanol, propanol or isopropanol.

8. Use of a carambola-shaped CuO / Cu-MOF electrocatalyst prepared as claimed in claim 1, characterized in that The carambola-shaped CuO / Cu-MOF electrocatalyst was used as raw material to prepare gas diffusion electrodes for electrocatalytic CO2 reduction.

9. The use of a carambola-shaped CuO / Cu-MOF electrocatalyst according to claim 8, characterized in that The gas diffusion electrode is specifically prepared according to the following steps: ① Add the carambola-shaped CuO / Cu-MOF electrocatalyst to a mixed solution of Nafion and isopropanol, and mix them ultrasonically for 10 min to 60 min at a power of 100 W to 500 W to obtain a catalyst ink; The volume ratio of Nafion solution to isopropanol in the mixed solution of Nafion and isopropanol is 1:(10-30); the concentration of the carambola-shaped CuO / Cu-MOF electrocatalyst in the catalyst ink is 3 mg / mL-10 mg / mL; ② According to the loading amount of carambola-shaped CuO / Cu-MOF electrocatalyst is 0.5 mg / cm 2 ~2.0mg / cm 2 , the catalyst ink is sprayed onto carbon paper at a temperature of 35°C to 65°C, and finally dried to obtain a gas diffusion electrode.

10. The use of a carambola-shaped CuO / Cu-MOF electrocatalyst according to claim 9, characterized in that The electrocatalytic CO2 reduction is specifically carried out according to the following steps: ① Assembly: Using a flow-type electrolyzer, a gas diffusion electrode is set between the CO2 gas flow chamber and the cathode chamber, and an anion exchange membrane is set between the cathode chamber and the anode chamber; the counter electrode is set in the anode chamber, the reference electrode is set in the cathode chamber, and the cathode liquid flow cell is connected to the cathode chamber through a conduit, and the anode liquid flow cell is connected to the anode chamber through a conduit, and the electrolyte is poured into the cathode liquid flow cell and the anode liquid flow cell, and finally the positive electrode of the power supply is connected to the counter electrode, and the negative electrode of the power supply is connected to the gas diffusion electrode; ②Electrocatalytic activation: CO2 gas is introduced into the CO2 gas flow chamber at a flow rate of 1 mL / min to 50 mL / min, and CO2 is continuously introduced. Under the condition that the potential applied to the gas diffusion electrode is -1.0 V to -3.0 V vs Ag / AgCl, the catalyst is activated for 5 min to 60 min. ③Electrocatalytic CO2 reduction: CO2 gas is introduced into the CO2 gas flow chamber at a flow rate of 1 mL / min to 50 mL / min. CO2 is continuously introduced at a current density of 50 mA cm at the gas diffusion electrode. -2 ~900mA·cm -2 Electrocatalytic CO2 reduction is performed under the conditions of , collecting gas products, separating and purifying the electrolyte after the reaction, and thus completing the electrocatalytic CO2 reduction; The electrolyte described in step ① is a KOH electrolyte with a concentration of 0.5M to 5M; the material of the CO2 gas flow chamber described in step ① is stainless steel; the counter electrode described in step ① is foamed Ni, Pt-plated titanium felt or IrO2-plated titanium felt; the reference electrode described in step ① is an Ag / AgCl electrode.

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