阅读说明：本技术 一种用于co2电还原制乙醇的铜催化剂及其制备方法与应用 (For CO2Copper catalyst for preparing ethanol by electroreduction and preparation method and application thereof ) 是由 肖睿 徐维聪 刘超 巩峰 孙向阳 于 2021-08-23 设计创作，主要内容包括：本发明公开了一种用于CO-(2)电还原制乙醇的铜催化剂及其制备方法与应用,属于电催化领域；本发明所述的通过控制铜表面生长的垂直石墨烯实现催化剂表面阶梯状位点纵向深度和数量的可控调节,并能够将铜表面原有的低表面能Cu(100)、Cu(111)晶面重组为高表面能Cu(110)、Cu(210)、Cu(310)晶面,表现出高表面能所特有的原子排列特性；表面呈周期性阶梯状的铜催化剂具有较低的C-C偶联势垒和较好的乙醇反应路径,可实现电催化CO-(2)还原制备乙醇燃料,并具有较高的选择性。(The invention discloses a method for preparing CO 2 A copper catalyst for preparing ethanol by electroreduction, a preparation method and application thereof, belonging to the field of electrocatalysis; according to the invention, the longitudinal depth and the number of the stepped sites on the surface of the catalyst can be controllably adjusted by controlling the vertical graphene grown on the surface of copper, and the original low surface energy Cu (100) and Cu (111) crystal planes on the surface of copper can be recombined into high surface energy Cu (110), Cu (210) and Cu (310) crystal planes, so that the characteristic of atomic arrangement of high surface energy is shown; the copper catalyst with the surface in the periodic step shape has lower C-C coupling potential barrier and better ethanol reaction path, and can realize the electrocatalysis of CO 2 Reduction for preparing ethanol fuel, and hasHas higher selectivity.)

1. For CO₂The copper catalyst for preparing ethanol by electroreduction is characterized in that metal copper is used as a main body of the catalyst, stepped sites with high surface energy are used as active sites, the longitudinal depth and the number of the stepped sites with high surface energy can be controllably adjusted, and the longitudinal depth is 0.1-20 nm.

2. A process for CO according to claim 1₂The copper catalyst for preparing ethanol by electroreduction is characterized in that the high surface energy stepThe active sites are Cu (110), Cu (210) and Cu (310) crystal planes.

3. A process for CO according to claim 1₂The copper catalyst for preparing ethanol by electroreduction is characterized in that the main body of the metal copper is one of copper foil or foam copper.

4. Use according to any of claims 1 to 3 for CO₂The preparation method of the copper catalyst for preparing ethanol by electroreduction is characterized by comprising the following specific operation steps:

step 1, carrying out acid cleaning on the polished copper to remove surface impurities and an oxide layer;

step 2, growing vertical graphene with different sizes on the surface of the pickled copper by using a plasma enhanced vapor chemical deposition method, and regulating and controlling the surface of the copper to generate high surface energy stepped sites with different longitudinal depths and different quantities according to the thermal expansion energy difference of the vertical graphene and the pickled copper;

and 3, putting copper growing vertical graphene into electrolyte for electrolysis, stripping graphene attached to the surface, washing with deionized water, and drying with nitrogen to obtain the catalyst.

5. A process for CO according to claim 4₂The preparation method of the copper catalyst for preparing ethanol by electroreduction is characterized in that in the step 2, ethylene is used as reaction gas in the plasma enhanced gas phase chemical deposition, the reaction temperature is 600-700 ℃, the reaction time is 60-300 min, the radio frequency power is 150-400W, and the height of the grown vertical graphene is 0.1-10 mu m.

6. A process for CO according to claim 4₂The preparation method of the copper catalyst for preparing ethanol by electroreduction is characterized in that the solution in the step 3 is KHCO₃The concentration of the solution is 0.1-1 mol/L, the electrolysis time is 50-600 s, and the electrolysis voltage is-2 to-0.5V.

7. Use according to any of claims 1 to 6 for CO₂Copper catalyst for preparing ethanol by electroreduction in CO₂The application of electroreduction in ethanol preparation is characterized in that copper containing controllable high-surface-energy stepped active sites is used as a catalyst and a working electrode, and the copper catalyst can efficiently catalyze CO in electrolyte₂Reducing the ethanol into ethanol by the following specific operation steps:

step a, putting a copper catalyst containing a controllable high-surface-energy stepped active site into a catholyte with a certain concentration;

step b, sealing the electrolytic cell, and introducing CO into the cathode electrolytic cell₂Presaturating the electrolyte and activating the working electrode;

step c, after the activation is finished, continuously introducing CO₂Under the condition of (1), constant potential electrolysis is adopted to obtain the ethanol.

8. A process for CO according to claim 7₂Copper catalyst for preparing ethanol by electroreduction in CO₂The application of electroreduction in ethanol preparation is characterized in that the catholyte in the step a is KHCO₃One of the solution or KCl solution with the concentration of 0.1-1 mol/L.

9. A process for CO according to claim 7₂Copper catalyst for preparing ethanol by electroreduction in CO₂The application of electroreduction to ethanol production is characterized in that CO is introduced into the cathode electrolytic cell in the step b₂The presaturation time of the electrolyte is 10-40 min.

10. A process for CO according to claim 7₂Copper catalyst for preparing ethanol by electroreduction in CO₂The application of electroreduction in ethanol preparation is characterized in that the constant potential in the step c is-1.0 to-0.8V, and the electrolysis time is 40 to 240 min.

Technical Field

The invention belongs to the field of electrochemistry and new energy materials, relates to a copper catalyst, a preparation method and application thereof, and particularly relates to a copper catalyst containing controllable high-surface-energy stepped active sites, a preparation method thereof and a catalyst prepared by the methodO₂Application in preparing ethanol by electroreduction.

Background

With the growing energy and environmental concerns, the recycling of "hazardous" resources has become a more pressing task for mankind. CO2₂As a main gas of the greenhouse effect, the compound is converted into valuable chemicals and has huge development potential. At present, researchers have proposed various COs₂Such as catalytic hydrogenation, electrochemical reduction, biotransformation, etc. Among them, electrocatalysis is one of the methods with development prospect because of controllable reaction rate, high product selectivity, mild reaction conditions, easy modularization and capability of amplifying reaction ratio as required to meet industrial requirements. Among the catalytic materials, copper is unique in that it is capable of donating CO to₂Reduction to valuable multi-carbon products, e.g. ethylene (C)₂H₄) Ethanol (C)₂H₅OH), etc., but copper-based catalysts are being obtained with high Faraday efficiency and high current density C₂At the same time as the product, Hydrogen Evolution Reaction (HER) is liable to occur so that the faradaic efficiency of the product is lowered. By now, most of the relevant research is focused on the stepped active sites of the copper catalyst with specific longitudinal depth, the coupling of key intermediates CHO and CO is too single for research, so the longitudinal depth and the number of the stepped sites on the surface of the copper catalyst can be controlled and adjusted, and the coupling of the key intermediates CHO and CO and the generation of C are further researched₂The influence of the product is significant. The current research and simulation results based on single crystals show that the Cu (100) and Cu (111) crystal faces with low surface energy step-shaped sites are not favorable for C-C bond coupling to form C₂The product, which does not have the optimal converted gibbs free energy at low surface energy stepped sites, has a higher energy barrier for binding to intermediates or adsorbates, resulting in desorption of intermediates CO from the catalyst surface to CO, resulting in a generally lower selectivity for ethanol. On the contrary, the high surface energy stepped site has the best conversion Gibbs free energy, the stepped site has lower coordination number, the energy barrier of the combined intermediate or adsorbate is lower, and the coupling of key intermediates such as CHO and CO is facilitated to form C₂And (3) obtaining the product. Therefore, the development of a copper-based catalyst having stepped sites with high surface energy having a specific atomic arrangement and in which the longitudinal depth and number of the stepped sites can be controllably adjusted is now being used for CO₂One of the key points of the research on the preparation of ethanol by electroreduction.

Disclosure of Invention

The present invention aims to overcome the defects of the prior art and provide a method for CO₂A copper catalyst for preparing ethanol by electroreduction, a preparation method and application thereof.

In order to solve the problems, the technical scheme adopted by the invention is as follows:

the invention aims to provide a copper catalyst containing controllable high-surface-energy stepped active sites.

For CO₂The copper catalyst for preparing ethanol by electroreduction takes metal copper as a main body and takes stepped sites with high surface energy as active sites, wherein the longitudinal depth and the number of the stepped sites with high surface energy can be controllably adjusted, and the longitudinal depth is 0.1-20 nm.

Furthermore, the high surface energy stepped active sites are Cu (110), Cu (210) and Cu (310) crystal planes.

Further, the metal copper is one of copper foil or foam copper.

The invention also aims to provide a preparation method of the copper catalyst with controllable high surface energy step-shaped active sites.

For CO₂The preparation method of the copper catalyst for preparing ethanol by electroreduction comprises the following steps:

step 1, carrying out acid cleaning on the polished copper to remove surface impurities and an oxide layer;

step 2, growing vertical graphene with different sizes on the surface of the pickled copper by using a plasma enhanced vapor chemical deposition method, and regulating and controlling the surface of the copper to generate high surface energy stepped sites with different longitudinal depths and different quantities according to the thermal expansion energy difference of the vertical graphene and the pickled copper;

and 3, putting the copper with the vertical graphene growth into an electrolyte for electrolysis, stripping the graphene attached to the surface, washing with deionized water, and drying with nitrogen to obtain the copper catalyst.

Further, in the step 2, ethylene is used as reaction gas in the plasma enhanced vapor phase chemical deposition, the reaction temperature is 600-700 ℃, the reaction time is 60-300 min, the radio frequency power is 150-400W, and the height of the grown vertical graphene is 0.1-10 mu m.

Further, in the step 3, the electrolyte is KHCO₃The concentration of the solution is 0.1-1 mol/L, the electrolysis time is 50-600 s, and the electrolysis voltage is-2 to-0.5V.

The invention also aims to provide a copper catalyst based on the controllable high-surface-energy stepped active sites on CO₂An application method in preparing ethanol by electroreduction.

For CO₂Copper catalyst for preparing ethanol by electroreduction in CO₂The application of preparing ethanol by electroreduction takes copper containing controllable high surface energy step-shaped active sites as a catalyst and a working electrode, and the copper catalyst can efficiently catalyze CO in electrolyte₂Reducing the ethanol into ethanol by the following specific operation steps:

step a, putting a catalyst containing a controllable high-surface-energy stepped active site into a catholyte with a certain concentration;

step b, sealing the electrolytic cell, and introducing CO into the cathode electrolytic cell₂Presaturating the electrolyte and activating the working electrode;

step c, after the activation is finished, continuously introducing CO₂Under the condition of (1), electrolyzing at constant potential and normal temperature to obtain the ethanol.

Further, the catholyte in the step a is KHCO₃One of the solution or KCl solution with the concentration of 0.1-1 mol/L.

Further, introducing CO into the cathode electrolytic cell in the step b₂The presaturation time of the electrolyte is 10-40 min.

Further, the constant potential in the step c is-1.0 to-0.8V, and the electrolysis time is 40 to 240 min.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:

1. the catalyst can adjust the generation of high surface energy stepped sites on the surface of the catalyst and the longitudinal depth and the number of the high surface energy stepped sites by controlling the vertical graphene grown on the surface of copper, and the high surface energy stepped sites are used as active sites, so that the method for manufacturing the high surface energy stepped sites is simple in operation, controllable in process, low in cost and easy for large-scale production; 2. the surface of the catalyst obtained by the invention has sharp periodic stepped sites, mainly consists of Cu (110), Cu (210) and Cu (310) atoms in an arrangement mode, and provides stepped sites with high surface energy; 3. the periodic stepped copper surface obtained by the method has a lower C-C coupling potential barrier and a better ethanol reaction path, and can realize the electrocatalysis of CO on the basis of the nano copper₂Reducing to prepare ethanol with high yield; 4. copper with a periodically stepped surface also exhibits suitable CO binding energy for further reaction to form a polycarbonic product, such as C₂H₄And C₂、C₃Alcohols capable of stabilizing the production of C in a C-C dimerization step₂H₅Specific intermediates involved in OH.

Detailed Description

The following examples further describe embodiments of the present invention in detail. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

Example 1

Firstly, acid cleaning is carried out on polished copper foam, surface impurities and an oxide layer are removed, under the conditions that the reaction temperature is 600 ℃, the reaction time is 60min and the radio frequency power is 150W, the height of vertical graphene grown on the surface of the acid cleaned copper foam (0.3mm multiplied by 1cm) by using ethylene as reaction gas through plasma enhanced gas phase chemical deposition is 0.1 mu m, and the copper foam for growing the vertical graphene is obtained and is marked as A1.

Placing A1 into 0.1mol/L KHCO₃In the electrolyte, A1 is electrolyzed for 50s by a constant potential electrolysis method under the condition of-0.5 (V vs. Ag/AgCl) to strip graphene vertically grown on copper, the graphene is washed by deionized water after separation, and is dried by nitrogen to obtain the foam copper catalyst B1 with the surface step-shaped locus and the longitudinal depth of 0.1 nm.

Example 2

Firstly, acid cleaning is carried out on polished copper foam, surface impurities and an oxide layer are removed, under the conditions that the reaction temperature is 650 ℃, the reaction time is 180min and the radio frequency power is 275W, the height of vertical graphene grown on the surface of the acid cleaned copper foam (0.3mm multiplied by 1cm) by using ethylene as reaction gas through plasma enhanced gas phase chemical deposition is 5 mu m, and the copper foam for growing the vertical graphene is obtained and is marked as A2.

Placing A2 into 0.5mol/L KHCO₃In the electrolyte, A2 is electrolyzed for 300s by adopting a constant potential electrolysis method under the condition of-1.5 (V vs. Ag/AgCl) to strip graphene vertically grown on copper, the graphene is washed by deionized water after separation, and is dried by nitrogen to obtain the foam copper catalyst B2 with the surface step-shaped locus and the longitudinal depth of 10 nm.

Example 3

Firstly, acid cleaning is carried out on polished copper foam, surface impurities and an oxide layer are removed, under the conditions that the reaction temperature is 700 ℃, the reaction time is 300min and the radio frequency power is 400W, the height of vertical graphene grown on the surface of the acid cleaned copper foam (0.3mm multiplied by 1cm) by using ethylene as reaction gas through plasma enhanced vapor phase chemical deposition is 10 mu m, and the copper foam for growing the vertical graphene is obtained and is marked as A3.

Placing A3 into 1mol/L KHCO₃In the electrolyte, A3 is electrolyzed for 600s by a constant potential electrolysis method under the condition of-2 (V vs. Ag/AgCl) to strip graphene vertically grown on copper, the graphene is washed by deionized water after separation, and is dried by nitrogen to obtain the foam copper catalyst B3 with the surface step-shaped sites and the longitudinal depth of 20 nm.

Example 4

Firstly, carrying out acid cleaning on a polished copper foil to remove surface impurities and an oxidation layer, and under the conditions of a reaction temperature of 600 ℃, a reaction time of 60min and a radio frequency power of 150W, utilizing plasma enhanced vapor phase chemical deposition to take ethylene as a reaction gas, wherein the height of vertical graphene grown on the surface of the copper foil (0.25mm multiplied by 1cm) after acid cleaning is 0.1 mu m, and obtaining the copper foil with the vertical graphene grown, which is marked as A4.

Placing A4 into 0.1mol/L KHCO₃In the electrolyte, constant current is adoptedAnd (3) stripping graphene vertically grown on copper from A4 by using an in-situ electrolysis method for 50s under the condition of-0.5 (V vs. Ag/AgCl), washing with deionized water after separation, and drying with nitrogen to obtain the copper foil catalyst B4 with the surface stepped sites having the longitudinal depth of 0.1 nm.

Example 5

Firstly, carrying out acid cleaning on a polished copper foil to remove surface impurities and an oxidation layer, and under the conditions of reaction temperature of 650 ℃, reaction time of 180min and radio frequency power of 275W, utilizing plasma enhanced vapor phase chemical deposition to take ethylene as reaction gas, wherein the height of vertical graphene grown on the surface of the copper foil (0.25mm multiplied by 1cm) after acid cleaning is 5 mu m, and obtaining the copper foil with the vertical graphene grown, which is marked as A5.

Placing A5 into 0.5mol/L KHCO₃In the electrolyte, A5 is electrolyzed for 300s by adopting a constant potential electrolysis method under the condition of-1.5 (V vs. Ag/AgCl) to strip graphene vertically grown on copper, the graphene is washed by deionized water after separation, and is dried by nitrogen to obtain the copper foil catalyst B5 with the surface step-shaped locus and the longitudinal depth of 10 nm.

Example 6

Firstly, carrying out acid cleaning on a polished copper foil to remove surface impurities and an oxidation layer, and under the conditions of a reaction temperature of 700 ℃, a reaction time of 300min and a radio frequency power of 400W, utilizing plasma enhanced vapor phase chemical deposition to take ethylene as a reaction gas, wherein the height of vertical graphene grown on the surface of the copper foil (0.25mm multiplied by 1cm) after acid cleaning is 10 mu m, so as to obtain the copper foil with the vertical graphene grown, and the copper foil is marked as A6.

Placing A6 into 1mol/L KHCO₃In the electrolyte, A6 is electrolyzed for 600s by a constant potential electrolysis method under the condition of-2 (V vs. Ag/AgCl) to strip graphene vertically grown on copper, the graphene is washed by deionized water after separation, and is dried by nitrogen to obtain the copper foil catalyst B6 with the surface step-shaped sites and the longitudinal depth of 20 nm.

The following examples are the CO catalysis of the copper foams and foils containing the controlled high surface energy stepped active sites described above₂Application example of the electroreduction to ethanol.

Example 7

Catalyst (0.3)mm × 1cm × 1cm) B1 was pre-saturated with CO2 for 10min at a concentration of 0.1mol/LKHCO₃In an H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.8 (V vs. RHE)₂Reducing for 40 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 13.1%.

Example 8

Catalyst (0.3mm × 1cm × 1cm) B1 was placed in a container containing CO₂Pre-saturated for 20min 0.5mol/L KHCO₃In an H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.8 (V vs. RHE)₂And reducing for 120 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 16.0%.

Example 9

Catalyst (0.3mm × 1cm × 1cm) B1 was placed in a container containing CO₂Presaturation of 1mol/L KHCO for 40min₃In an H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.8 (V vs. RHE)₂Reducing for 240 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 16.8%.

Example 10

Catalyst (0.3mm × 1cm × 1cm) B1 was placed in a container containing CO₂Presaturating for 10min in 0.1mol/L KCl H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.8 (V vs. RHE)₂Reducing for 40 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 18.3%.

Example 11

Catalyst (0.3mm × 1cm × 1cm) B1 was placed in a container containing CO₂Presaturating for 20min in 0.5mol/L KCl H-type electrolytic cell, continuously introducing CO₂And adopts a constant-potential electrolysis method,electrocatalysis of CO at-0.8 (V vs. RHE) voltage₂And reducing for 120 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 21.4%.

Example 12

Catalyst (0.3mm × 1cm × 1cm) B1 was placed in a container containing CO₂Presaturating for 40min in an H-type electrolytic cell of 1mol/L KCl, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.8 (V vs. RHE)₂Reducing for 240 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 22.0%.

Example 13

Catalyst (0.3mm × 1cm × 1cm) B2 was placed in a container containing CO₂0.1mol/L KHCO presaturated for 10min₃In an H-type electrolytic cell, continuously introducing CO₂And adopting a constant potential electrolysis method to electrocatalysis CO under the voltage condition of-1 (V vs. RHE)₂Reducing for 40 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 13.6%.

Example 14

Catalyst (0.3mm × 1cm × 1cm) B2 was placed in a container containing CO₂Pre-saturated for 20min 0.5mol/L KHCO₃In an H-type electrolytic cell, continuously introducing CO₂And adopting a constant potential electrolysis method to electrocatalysis CO under the voltage condition of-1 (V vs. RHE)₂And reducing for 120 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 15.7%.

Example 15

Catalyst (0.3mm × 1cm × 1cm) B2 was placed in a container containing CO₂Presaturation of 1mol/L KHCO for 40min₃In an H-type electrolytic cell, continuously introducing CO₂And adopting a constant potential electrolysis method to electrocatalysis CO under the voltage condition of-1 (V vs. RHE)₂Reducing for 240 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR measurement of the product compositionDividing; the result is: the ethanol faradaic efficiency was 17.8%.

Example 16

Catalyst (0.3mm × 1cm × 1cm) B2 was placed in a container containing CO₂Presaturating for 10min in 0.1mol/L KCl H-type electrolytic cell, continuously introducing CO₂And adopting a constant potential electrolysis method to electrocatalysis CO under the voltage condition of-1 (V vs. RHE)₂Reducing for 40 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 18.9%.

Example 17

Catalyst (0.3mm × 1cm × 1cm) B2 was placed in a container containing CO₂Presaturating for 20min in 0.5mol/L KCl H-type electrolytic cell, continuously introducing CO₂And adopting a constant potential electrolysis method to electrocatalysis CO under the voltage condition of-1 (V vs. RHE)₂And reducing for 120 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 22.4%.

Example 18

Catalyst (0.3mm × 1cm × 1cm) B2 was placed in a container containing CO₂Presaturating for 40min in an H-type electrolytic cell of 1mol/L KCl, continuously introducing CO₂And adopting a constant potential electrolysis method to electrocatalysis CO under the voltage condition of-1 (V vs. RHE)₂Reducing for 240 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 23.9%.

Example 19

Catalyst (0.3mm × 1cm × 1cm) B3 was placed in a container containing CO₂0.1mol/L KHCO presaturated for 10min₃In an H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.9 (V vs. RHE)₂Reducing for 40 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 13.7%.

Example 20

Placing catalyst (0.3mm × 1cm × 1cm) B3 into the containerWith the passage of CO₂Pre-saturated for 20min 0.5mol/L KHCO₃Continuously introducing CO2 into the H-type electrolytic cell, and electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.9 (V vs. RHE)₂And reducing for 120 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 17%.

Example 21

Catalyst (0.3mm × 1cm × 1cm) B3 was placed in a container containing CO₂Presaturation of 1mol/L KHCO for 40min₃In an H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.9 (V vs. RHE)₂Reducing for 240 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 19.0%.

Example 22

Catalyst (0.3mm × 1cm × 1cm) B3 was placed in a container containing CO₂Presaturating for 10min in 0.1mol/L KCl H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.9 (V vs. RHE)₂Reducing for 40 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 20.0%.

Example 23

Catalyst (0.3mm × 1cm × 1cm) B3 was placed in a container containing CO₂Presaturating for 20min in 0.5mol/L KCl H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.9 (V vs. RHE)₂And reducing for 120 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 24.0%.

Example 24

Catalyst (0.3mm × 1cm × 1cm) B3 was placed in a container containing CO₂Presaturating for 40min in an H-type electrolytic cell of 1mol/L KCl, continuously introducing CO₂And adopts a constant potential electrolysis method to perform electrocatalysis under the voltage condition of-0.9 (V vs. RHE)To convert CO₂Reducing for 240 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 27.0%.

Example 25

Catalyst (0.25 mm. times.1 cm) B4 was placed in a container containing CO₂Presaturation for 10min of 0.1mol/LKHCO₃In an H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.8 (V vs. RHE)₂Reducing for 40 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 12.3%.

Example 26

Catalyst (0.25 mm. times.1 cm) B4 was placed in a container containing CO₂Presaturation for 20min of 0.5mol/LKHCO₃In an H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.8 (V vs. RHE)₂And reducing for 120 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 15.7%.

Example 27

Catalyst (0.25 mm. times.1 cm) B4 was placed in a container containing CO₂Presaturation of 1mol/L KHCO for 40min₃In an H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.8 (V vs. RHE)₂Reducing for 240 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 16.4%.

Example 28

Catalyst (0.25 mm. times.1 cm) B4 was placed in a container containing CO₂Presaturating for 10min in 0.1mol/L KCl H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.8 (V vs. RHE)₂Reducing for 40 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: ethanol processThe pull-to-third efficiency was 17.8%.

Example 29

Catalyst (0.25 mm. times.1 cm) B4 was placed in a container containing CO₂Presaturating for 20min in 0.5mol/L KCl H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.8 (V vs. RHE)₂And reducing for 120 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 20.6%.

Example 30

Catalyst (0.25 mm. times.1 cm) B4 was placed in a container containing CO₂Presaturating for 40min in an H-type electrolytic cell of 1mol/L KCl, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.8 (V vs. RHE)₂Reducing for 240 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 21.3%.

Example 31

Catalyst (0.25 mm. times.1 cm) B5 was placed in a container containing CO₂Presaturation for 10min of 0.1mol/LKHCO₃In an H-type electrolytic cell, continuously introducing CO₂And adopting a constant potential electrolysis method to electrocatalysis CO under the voltage condition of-1 (V vs. RHE)₂Reducing for 40 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 13.4%.

Example 32

Catalyst (0.25 mm. times.1 cm) B5 was placed in a container containing CO₂Presaturation for 20min of 0.5mol/LKHCO₃In an H-type electrolytic cell, continuously introducing CO₂And adopting a constant potential electrolysis method to electrocatalysis CO under the voltage condition of-1 (V vs. RHE)₂And reducing for 120 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 15.2%.

Example 33

Placing catalyst (0.25mm × 1cm × 1cm) B5 in a container containing catalyst CO₂Presaturation of 1mol/L KHCO for 40min₃In an H-type electrolytic cell, continuously introducing CO₂And adopting a constant potential electrolysis method to electrocatalysis CO under the voltage condition of-1 (V vs. RHE)₂Reducing for 240 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 16%.

Example 34

Catalyst (0.25 mm. times.1 cm) B5 was placed in a container containing CO₂Presaturating for 10min in 0.1mol/L KCl H-type electrolytic cell, continuously introducing CO₂And adopting a constant potential electrolysis method to electrocatalysis CO under the voltage condition of-1 (V vs. RHE)₂Reducing for 40 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 16.3%.

Example 35

Catalyst (0.25 mm. times.1 cm) B5 was placed in a container containing CO₂Presaturating for 20min in 0.5mol/L KCl H-type electrolytic cell, continuously introducing CO₂And adopting a constant potential electrolysis method to electrocatalysis CO under the voltage condition of-1 (V vs. RHE)₂And reducing for 120 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 21.7%.

Example 36

Catalyst (0.25 mm. times.1 cm) B5 was placed in a container containing CO₂Presaturating for 40min in an H-type electrolytic cell of 1mol/L KCl, continuously introducing CO₂And adopting a constant potential electrolysis method to electrocatalysis CO under the voltage condition of-1 (V vs. RHE)₂Reducing for 240 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 22.3%.

Example 37

Catalyst (0.25 mm. times.1 cm) B6 was placed in a container containing CO₂Presaturation for 10min of 0.1mol/LKHCO₃In an H-type electrolytic cell, continuously introducing CO₂And electrocatalysis is carried out under the voltage condition of-0.9 (V vs. RHE) by adopting a constant potential electrolysis methodCO₂Reducing for 40 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 13.5%.

Example 38

Catalyst (0.25 mm. times.1 cm) B6 was placed in a container containing CO₂Presaturation for 20min of 0.5mol/LKHCO₃In an H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.9 (V vs. RHE)₂And reducing for 120 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 16.7%.

Example 39

Catalyst (0.25 mm. times.1 cm) B6 was placed in a container containing CO₂Presaturation of 1mol/L KHCO for 40min₃In an H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.9 (V vs. RHE)₂Reducing for 240 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 17.6%.

Example 40

Catalyst (0.25 mm. times.1 cm) B6 was placed in a container containing CO₂Presaturating for 10min in 0.1mol/L KCl H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.9 (V vs. RHE)₂Reducing for 40 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 18.9%.

EXAMPLE 41

Catalyst (0.25 mm. times.1 cm) B6 was placed in a container containing CO₂Presaturating for 20min in 0.5mol/L KCl H-type electrolytic cell, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.9 (V vs. RHE)₂And reducing for 120 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: faraday efficiency of ethanol of23.1％。

Example 42

Catalyst (0.25 mm. times.1 cm) B6 was placed in a container containing CO₂Presaturating for 40min in an H-type electrolytic cell of 1mol/L KCl, continuously introducing CO₂And electrocatalysis of CO by adopting a constant potential electrolysis method under the voltage condition of-0.9 (V vs. RHE)₂Reducing for 240 min. After the reaction is finished, collecting liquid-phase product, and making it pass through¹H-NMR to determine the product composition; the result is: the ethanol faradaic efficiency was 26.3%.

To summarize: from the above embodiments, it can be found that as the height of the vertical graphene grown on the copper surface increases, the longitudinal depth of the stepped sites with high surface energy generated on the surface of the catalyst gradually increases, and the faradaic efficiency of ethanol also gradually increases. Therefore, the longitudinal depth of the high surface energy stepped sites on the surface of the catalyst is controlled, so that the energy barrier of the bound intermediate or adsorbate can be effectively reduced, and the key intermediates CHO and CO are coupled to generate an ethanol product.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.