Preparation method and application of CuO / hollow structure CeO2 electrocatalyst

Abstract

The invention discloses a preparation method and application of a CuO / hollow structure CeO2 electrocatalyst, and relates to a preparation method and application of an electrocatalyst. The invention aims to solve the problems of low selectivity of a CO2 reduction product CH4 and low applied current density in the existing electrocatalytic CO2 reduction technology. The method comprises the following steps: 1, preparing a precursor solution; 2, separating, washing and drying; 3, roasting; (4) etching; and 5, dipping. According to the application, the CuO / hollow structure CeO2 electrocatalyst is used as a raw material for preparing a gas diffusion electrode and is used for electrocatalytic CO2 reduction. The preparation method is used for preparation and application of the CuO / hollow structure CeO2 electrocatalyst.

Description

Technical Field

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

[0002] Electrocatalytic CO2 reduction technology converts carbon dioxide into useful chemicals and fuels, such as methane and ethylene, through electrochemical reactions. It can not only effectively reduce the carbon dioxide content in the atmosphere, but also provide new ideas for the recycling of sustainable energy. The core of this technology lies in the development of efficient catalysts to improve the selectivity and conversion rate of the reaction.

[0003] In the electrocatalytic reduction of CO2, copper (Cu) has been widely studied as a catalyst material with outstanding performance. Copper can efficiently reduce CO2 to multi-carbon products, such as ethylene and ethanol. However, pure Cu catalysts still have room for improvement in activity and stability. Therefore, many researchers are committed to developing new copper-based composite catalysts to further optimize catalytic performance. However, there are still problems such as low selectivity of CO2 reduction product CH4 and low applied current density. Summary of the invention

[0004] The present invention aims to solve the problems of low selectivity of CO2 reduction product CH4 and low applied current density in the existing electrocatalytic CO2 reduction technology, and further provide a preparation method and application of a CuO / hollow structure CeO2 electrocatalyst.

[0005] A method for preparing a CuO / hollow structure CeO2 electrocatalyst is carried out according to the following steps:

[0006] 1. Preparation of precursor solution:

[0007] Spherical SiO2 is added to water for ultrasonic dispersion to obtain SiO2 dispersion, and then cerium salt, precipitant and surfactant are added to the SiO2 dispersion under stirring conditions and mixed evenly, and finally stirred for reaction at a temperature of 60°C to 150°C for 3h to 24h to obtain a precursor solution;

[0008] 2. Separation, washing and drying:

[0009] Separating, washing and drying the precursor solution in sequence to obtain a precursor;

[0010] 3. Roasting:

[0011] The precursor is calcined for 1 h to 4 h in an air atmosphere at a temperature of 200° C. to obtain a precursor SiO2@CeO2;

[0012] 4. Etching:

[0013] The precursor SiO2@CeO2 is added to the etchant, and the etching is performed for 12 hours to 36 hours at room temperature and a rotation speed of 400 r / min to 1200 r / min, and then washed and dried to obtain a hollow structure CeO2;

[0014] 5. Impregnation:

[0015] The hollow structure CeO2 is added into the copper salt solution and stirred and mixed, and then calcined for 3h to 6h at a temperature of 473K to 873K to obtain a CuO / hollow structure CeO2 electrocatalyst.

[0016] The invention discloses an application of a CuO / hollow structure CeO2 electrocatalyst. The CuO / hollow structure CeO2 electrocatalyst is used as a raw material to prepare a gas diffusion electrode for electrocatalytic CO2 reduction.

[0017] The beneficial effects of the present invention are:

[0018] The CuO / hollow structure CeO2 electrocatalyst prepared by the present invention exhibits excellent electrocatalytic CO2 reduction performance. -2 The selectivity of CH4 reached 44% at a current density of 1.54 W.

[0019] The CuO / hollow structure CeO2 electrocatalyst prepared by the present invention has a simple process, good scalability, and can be mass-produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 XRD images of the hollow structure CeO2 prepared in step 4 of Example 1 and the CuO / hollow structure CeO2 electrocatalyst prepared in step 5;

[0021] Figure 2 This is a scanning electron microscope image of the hollow structure CeO2 prepared in step 4 of Example 1;

[0022] Figure 3 This is a scanning electron microscope image of the CuO / hollow structure CeO2 electrocatalyst prepared in Example 1;

[0023] Figure 4 This is the XPS image of the CuO / hollow structure CeO2 electrocatalyst prepared in Example 1;

[0024] Figure 5 This is the curve of CO2 reduction product selectivity of the CuO / hollow structure CeO2 electrocatalyst prepared in Example 1 as a function of applied current density. DETAILED DESCRIPTION

[0025] Specific implementation method 1: This implementation method is a method for preparing a CuO / hollow structure CeO2 electrocatalyst, which is carried out according to the following steps:

[0026] 1. Preparation of precursor solution:

[0027] Spherical SiO2 is added to water for ultrasonic dispersion to obtain SiO2 dispersion, and then cerium salt, precipitant and surfactant are added to the SiO2 dispersion under stirring conditions and mixed evenly, and finally stirred for reaction at a temperature of 60°C to 150°C for 3h to 24h to obtain a precursor solution;

[0028] 2. Separation, washing and drying:

[0029] Separating, washing and drying the precursor solution in sequence to obtain a precursor;

[0030] 3. Roasting:

[0031] The precursor is calcined for 1 h to 4 h in an air atmosphere at a temperature of 200° C. to obtain a precursor SiO2@CeO2;

[0032] 4. Etching:

[0033] The precursor SiO2@CeO2 is added to the etchant, and the etching is performed for 12 hours to 36 hours at room temperature and a rotation speed of 400 r / min to 1200 r / min, and then washed and dried to obtain a hollow structure CeO2;

[0034] 5. Impregnation:

[0035] The hollow structure CeO2 is added into the copper salt solution and stirred and mixed, and then calcined for 3h to 6h at a temperature of 473K to 873K to obtain a CuO / hollow structure CeO2 electrocatalyst.

[0036] In this specific embodiment, copper oxide is loaded on cerium oxide (H-CeO2) with a hollow structure, which can significantly improve the activity and stability of the catalyst. The hollow structure provides a larger specific surface area and more active sites, while the oxygen storage capacity of H-CeO2 helps to regulate the redox environment during the reaction process, thereby promoting the efficient conduct of the CO2 reduction reaction.

[0037] The beneficial effects of this embodiment are:

[0038] The CuO / hollow structure CeO2 electrocatalyst prepared in this embodiment exhibits excellent electrocatalytic CO2 reduction performance. -2 The selectivity of CH4 reached 44% at a current density of 1.54 W.

[0039] The CuO / hollow structure CeO2 electrocatalyst prepared in this embodiment has a simple process, good scalability, and can be mass-produced.

[0040] Specific embodiment 2: This embodiment is different from specific embodiment 1 in that: the particle size of the spherical SiO2 described in step 1 is 100nm to 500nm; the cerium salt described in step 1 is cerium nitrate or cerium chloride; the precipitant described in step 1 is sodium carbonate, sodium bicarbonate, urea or hexamethylenetetramine; the surfactant described in step 1 is polyvinyl pyrrolidone, N-methylpyrrolidone, octadecyltrimethylammonium bromide or sodium secondary alkyl sulfonate. The rest is the same as specific embodiment 1.

[0041] Specific embodiment 3: This embodiment differs from specific embodiment 1 or 2 in that: the concentration of spherical SiO2 in the SiO2 dispersion described in step 1 is 0.1 mg / mL to 10 mg / mL; the molar ratio of spherical SiO2 to cerium salt described in step 1 is 1:(0.2 to 1); the molar ratio of spherical SiO2 to precipitant described in step 1 is 1:(0.2 to 1); the mass ratio of spherical SiO2 to surfactant described in step 1 is 1:(5 to 20). Others are the same as specific embodiment 1 or 2.

[0042] Specific implementation method 4: This implementation method is different from specific implementation methods 1 to 3 in that the separation, washing and drying described in step 2 are specifically carried out according to the following steps: centrifugation for 2min to 10min at a rotation speed of 4000rpm to 9000rpm to obtain particles, and then using anhydrous ethanol and water as washing liquid to wash until the foam of the solution disappears, and finally drying the washed particles for 12h to 24h at a temperature of 40℃ to 90℃; the washing and drying described in step 4 are specifically using anhydrous ethanol and water as washing liquid to wash until neutral, and then drying for 12h to 24h at a temperature of 40℃ to 90℃. The rest is the same as specific implementation method 3.

[0043] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that: the mass ratio of the precursor SiO2@CeO2 to the etchant in step 4 is 1 g: (30-150) mL; the etchant in step 4 is a NaOH solution or a KOH solution; the concentration of the etchant in step 4 is 1 M to 15 M. Others are the same as specific embodiments 1 to 4.

[0044] Specific embodiment 6: This embodiment is different from specific embodiments 1 to 5 in that: the copper salt solution described in step 5 is a copper chloride solution or a copper nitrate solution; the concentration of the copper salt solution described in step 5 is 1 mg / mL to 50 mg / mL; the molar ratio of the hollow structure CeO2 described in step 5 to the copper salt in the copper salt solution is 1:(0.2 to 2). Others are the same as specific embodiments 1 to 5.

[0045] Specific implementation method seven: This implementation method is an application of CuO / hollow structure CeO2 electrocatalyst. The CuO / hollow structure CeO2 electrocatalyst is used as a raw material to prepare a gas diffusion electrode for electrocatalytic CO2 reduction.

[0046] Specific embodiment eight: This embodiment differs from specific embodiment seven in that: the gas diffusion electrode is prepared according to the following steps:

[0047] ① Add the CuO / hollow structure CeO2 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;

[0048] The volume ratio of Nafion solution to isopropanol in the mixed solution of Nafion and isopropanol is 1:(10-35); the concentration of CuO / hollow structure CeO2 electrocatalyst in the catalyst ink is 3mg / mL-10mg / mL;

[0049] ② According to the loading amount of CuO / hollow structure CeO2 electrocatalyst is 0.5mg / 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 seventh embodiment.

[0050] The preparation of the gas diffusion electrode in this embodiment is simple to operate, and the CuO / hollow structure CeO2 electrocatalyst does not need to be pretreated. The CuO / hollow structure CeO2 electrocatalyst is a stable oxide and exists stably in an air atmosphere, and there is no need to consider the problem of air oxidation.

[0051] Specific embodiment 9: This embodiment is different from specific embodiment 7 or 8 in that: the electrocatalytic CO2 reduction is specifically carried out according to the following steps:

[0052] 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;

[0053] 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.

[0054] 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 ~1A·cm -2 Under the conditions of , the electrocatalytic CO2 reduction is carried out, the gas product is collected, and the electrolyte after the reaction is separated and purified, so as to complete the electrocatalytic CO2 reduction. The rest is the same as the specific embodiment seven or eight.

[0055] Specific embodiment 10: This embodiment differs from specific embodiments 7 to 9 in that: the electrolyte described in step ① is a KOH electrolyte with a concentration of 0.5M to 3M; 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. Others are the same as specific embodiments 7 to 9.

[0056] The following examples are used to verify the beneficial effects of the present invention:

[0057] Embodiment 1:

[0058] A method for preparing a CuO / hollow structure CeO2 electrocatalyst is carried out according to the following steps:

[0059] 1. Preparation of precursor solution:

[0060] Spherical SiO2 was added to water, and ultrasonically dispersed for 20 minutes at a power of 300 W to obtain a SiO2 dispersion, and then cerium salt, precipitant and surfactant were added to the SiO2 dispersion at a stirring speed of 800 r / min and mixed evenly, and finally stirred for 8 hours at a temperature of 100°C and a stirring speed of 800 r / min to obtain a precursor solution;

[0061] 2. Separation, washing and drying:

[0062] Separating, washing and drying the precursor solution in sequence to obtain a precursor;

[0063] 3. Roasting:

[0064] The precursor was calcined for 2 h in an air atmosphere at 400 °C to obtain the precursor SiO2@CeO2;

[0065] 4. Etching:

[0066] The precursor SiO2@CeO2 was added into the etchant, and etched for 24 h at room temperature and a rotation speed of 800 r / min, and then washed and dried to obtain a hollow structure CeO2;

[0067] 5. Impregnation:

[0068] Under the condition of stirring speed of 800r / min, the hollow structure CeO2 was added into the copper salt solution and stirred for 180min, and then calcined at a temperature of 400°C for 5h to obtain the CuO / hollow structure CeO2 electrocatalyst.

[0069] The average particle size of the spherical SiO2 described in step one is 300nm; the cerium salt described in step one is cerium nitrate; the precipitant described in step one is hexamethylenetetramine; the surfactant described in step one is polyvinyl pyrrolidone.

[0070] The concentration of spherical SiO2 in the SiO2 dispersion described in step one is 2 mg / mL; the molar ratio of spherical SiO2 to cerium salt described in step one is 1:0.5; the molar ratio of spherical SiO2 to precipitant described in step one is 1:0.5; the mass ratio of spherical SiO2 to surfactant described in step one is 1:10.

[0071] The separation, washing and drying described in step 2 are specifically carried out according to the following steps: centrifugation for 5 minutes at a rotation speed of 8000rpm to obtain particles, and then using anhydrous ethanol and water as washing liquids to wash until the foam in the solution disappears, and finally drying the washed particles at a temperature of 60°C for 12 hours; the washing and drying described in step 4 are specifically carried out using anhydrous ethanol and water as washing liquids to wash until neutral, and then drying at a temperature of 60°C for 12 hours.

[0072] The mass ratio of the precursor SiO2@CeO2 described in step 4 to the volume ratio of the etchant is 1g:75mL; the etchant described in step 4 is NaOH solution; the concentration of the etchant described in step 4 is 3M.

[0073] The copper salt solution described in step five is a copper nitrate solution; the concentration of the copper salt solution described in step five is 10 mg / mL; the molar ratio of the hollow structure CeO2 described in step five to the copper salt in the copper salt solution is 1:0.2.

[0074] Application of the CuO / hollow structure CeO2 electrocatalyst prepared as above, the CuO / hollow structure CeO2 electrocatalyst is used as a raw material to prepare a gas diffusion electrode for electrocatalytic CO2 reduction;

[0075] The gas diffusion electrode is specifically prepared according to the following steps:

[0076] ① Add the CuO / hollow structure CeO2 electrocatalyst to the mixed solution of Nafion and isopropanol, and mix them ultrasonically for 20 minutes at a power of 300 W to obtain catalyst ink;

[0077] The volume ratio of Nafion solution to isopropanol in the mixed solution of Nafion and isopropanol is 1:30; the concentration of CuO / hollow structure CeO2 electrocatalyst in the catalyst ink is 7 mg / mL;

[0078] ② According to the loading amount of CuO / hollow structure CeO2 electrocatalyst is 1.0mg / cm 2 , spraying the catalyst ink onto carbon paper at a temperature of 55°C, and finally drying to obtain a gas diffusion electrode;

[0079] The carbon paper is 28BC;

[0080] The electrocatalytic CO2 reduction is specifically carried out according to the following steps:

[0081] 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;

[0082] The electrolyte is a KOH electrolyte with a concentration of 1M; the material of the CO2 gas flow chamber is stainless steel; the counter electrode is foamed Ni; the reference electrode is an Ag / AgCl electrode; the anion exchange membrane is fumasepFAA-3-PK-130;

[0083] ②Electrocatalytic activation: CO2 gas was introduced into the CO2 gas flow chamber at a flow rate of 30 mL / min, and the CO2 was continuously introduced. The catalyst was activated for 20 min under the condition that the potential applied to the gas diffusion electrode was -2.0 V vs Ag / AgCl;

[0084] ③Electrocatalytic CO2 reduction: CO2 gas was introduced into the CO2 gas flow chamber at a flow rate of 30 mL / min. CO2 was continuously introduced at a current density of 50 mA cm at the gas diffusion electrode. -2 ~300mA·cm -2 The electrocatalytic CO2 reduction is completed by electrocatalytically reducing CO2 under the conditions of , collecting the gas product, separating and purifying the electrolyte after the reaction.

[0085] Figure 1 XRD images of the hollow CeO2 prepared in step 4 of Example 1 and the CuO / hollow CeO2 electrocatalyst prepared in step 5; it can be seen from the figure that the system without copper salt impregnation only shows the relevant diffraction peak of CeO2. The system impregnated with copper salt does not show the relevant diffraction peak of CuO, which may be due to the small particle size of the generated CuO.

[0086] Figure 2 This is a scanning electron microscope image of the hollow structure CeO2 prepared in step 4 of Example 1; Figure 3 This is a scanning electron microscope image of the CuO / hollow structure CeO2 electrocatalyst prepared in Example 1; it can be seen from the figure that before the copper salt is impregnated, CeO2 only shows a spherical morphology. After the copper salt is impregnated, the heterogeneous particles observed on the surface of CeO2 are the impregnated CuO.

[0087] Figure 4This is the XPS image of the CuO / hollow structure CeO2 electrocatalyst prepared in Example 1; as can be seen from the figure, no Cu peak was observed on CeO2 before copper salt was impregnated. After copper salt was impregnated, +2 valence Cu was observed on the surface of CeO2, further indicating the formation of CuO.

[0088] Figure 5 The curve of CO2 reduction product selectivity of the CuO / hollow CeO2 electrocatalyst prepared in Example 1 as a function of applied current density. As can be seen from the figure, as the applied current density of the CuO / hollow CeO2 electrocatalyst gradually increases, the CO selectivity gradually decreases, while the CH4 selectivity gradually increases. -2 The selectivity of CH4 reached 44% at a current density of 1.34%, indicating that at high current density, *CO was hydrogenated to generate CH4. At the same time, as the current density gradually increased, the selectivity of H2 showed a trend of first decreasing and then increasing, indicating that at high current density, *H promoted the formation of CH4. Excessive H* easily formed H2, resulting in an increase in H2 selectivity.

Claims

1. A method for preparing a CuO / hollow structure CeO2 electrocatalyst, characterized in that It is carried out in the following steps:

1. Preparation of precursor solution: Spherical SiO2 is added to water for ultrasonic dispersion to obtain SiO2 dispersion, and then cerium salt, precipitant and surfactant are added to the SiO2 dispersion under stirring conditions and mixed evenly, and finally stirred for reaction at a temperature of 60°C to 150°C for 3h to 24h to obtain a precursor solution; 2. Separation, washing and drying: Separating, washing and drying the precursor solution in sequence to obtain a precursor; 3. Roasting: The precursor is calcined for 1 h to 4 h in an air atmosphere at a temperature of 200° C. to obtain a precursor SiO2@CeO2; 4. Etching: The precursor SiO2@CeO2 is added to the etchant, and the etching is performed for 12 hours to 36 hours at room temperature and a rotation speed of 400 r / min to 1200 r / min, and then washed and dried to obtain a hollow structure CeO2; 5. Impregnation: The hollow structure CeO2 is added into the copper salt solution and stirred and mixed, and then calcined for 3h to 6h at a temperature of 473K to 873K to obtain a CuO / hollow structure CeO2 electrocatalyst.

2. The method for preparing a CuO / hollow structure CeO2 electrocatalyst according to claim 1, characterized in that The particle size of the spherical SiO2 described in step one is 100nm to 500nm; the cerium salt described in step one is cerium nitrate or cerium chloride; the precipitant described in step one is sodium carbonate, sodium bicarbonate, urea or hexamethylenetetramine; the surfactant described in step one is polyvinylpyrrolidone, N-methylpyrrolidone, octadecyltrimethylammonium bromide or sodium secondary alkyl sulfonate.

3. The method for preparing a CuO / hollow structure CeO2 electrocatalyst according to claim 1, characterized in that The concentration of spherical SiO2 in the SiO2 dispersion described in step one is 0.1 mg / mL~10 mg / mL; the molar ratio of spherical SiO2 to cerium salt described in step one is 1:(0.2~1); the molar ratio of spherical SiO2 to precipitant described in step one is 1:(0.2~1); the mass ratio of spherical SiO2 to surfactant described in step one is 1:(5~20).

4. The method for preparing a CuO / hollow structure CeO2 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: centrifugation for 2min to 10min at a rotation speed of 4000rpm to 9000rpm to obtain particles, and then using anhydrous ethanol and water as washing liquids to wash until the foam of the solution disappears, and finally drying the washed particles at a temperature of 40℃ to 90℃ for 12h to 24h; the washing and drying described in step 4 are specifically using anhydrous ethanol and water as washing liquids to wash until neutral, and then drying at a temperature of 40℃ to 90℃ for 12h to 24h.

5. The method for preparing a CuO / hollow structure CeO2 electrocatalyst according to claim 1, characterized in that The volume ratio of the mass of the precursor SiO2@CeO2 described in step 4 to the etchant is 1g:(30-150)mL; the etchant described in step 4 is NaOH solution or KOH solution; the concentration of the etchant described in step 4 is 1M-15M.

6. The method for preparing a CuO / hollow structure CeO2 electrocatalyst according to claim 1, characterized in that The copper salt solution described in step five is a copper chloride solution or a copper nitrate solution; the concentration of the copper salt solution described in step five is 1 mg / mL to 50 mg / mL; the molar ratio of the hollow structure CeO2 described in step five to the copper salt in the copper salt solution is 1:(0.2 to 2).

7. Use of a CuO / hollow structure CeO2 electrocatalyst prepared as claimed in claim 1, characterized in that CuO / hollow structure CeO2 electrocatalyst was used as raw material to prepare gas diffusion electrode for electrocatalytic CO2 reduction.

8. The use of a CuO / hollow structure CeO2 electrocatalyst according to claim 7, characterized in that The gas diffusion electrode is specifically prepared according to the following steps: ① Add the CuO / hollow structure CeO2 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:(10-35); the concentration of CuO / hollow structure CeO2 electrocatalyst in the catalyst ink is 3mg / mL-10mg / mL; ② According to the loading amount of CuO / hollow structure CeO2 electrocatalyst is 0.5mg / 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.

9. The use of a CuO / hollow structure CeO2 electrocatalyst according to claim 8, 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 and the current density at the gas diffusion electrode is 50 mA cm -2 ~1A·cm -2 The electrocatalytic CO2 reduction is completed by electrocatalytically reducing CO2 under the conditions of , collecting the gas product, separating and purifying the electrolyte after the reaction.

10. The use of a CuO / hollow structure CeO2 electrocatalyst according to claim 9, characterized in that The electrolyte described in step ① is a KOH electrolyte with a concentration of 0.5M to 3M; 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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