A high C 2+ Preparation method, product and application of selective carbon dioxide electro-reduction catalyst Ag / AgBr / Cu2O

Abstract

The present application provides a kind of high C 2+ The application discloses a preparation method, product and application of a selective carbon dioxide electro-reduction catalyst Ag / AgBr / Cu2O. The preparation method adopts a one-pot solvothermal reduction method, and by controlling the reaction conditions, silver species is synchronously generated in the form of metallic silver and silver bromide and firmly combined with a cuprous oxide substrate. The method route is simple, the reaction conditions are mild, and the product is controllable. When the obtained catalyst is applied to a carbon dioxide electro-reduction reaction, the introduction of Ag and the doping of Br in the catalyst produce a synergistic catalytic effect, effectively promote the C-C coupling path, and significantly improve the C 2+ product selectivity, the C 2+ product faraday efficiency reaches 82.7%, and the local current density reaches 121.7 mA·cm ‑2 -2. At the same time, the hydrogen evolution side reaction is effectively inhibited. The research provides a new idea for designing a high-performance CO2 conversion catalyst, and has important scientific value and industrial application potential.

Description

Technical Field

[0001] This invention belongs to the field of carbon dioxide electrochemical reduction technology, specifically relating to a high C... 2+ Preparation methods, products and applications of selective carbon dioxide electroreduction catalysts Ag / AgBr / Cu2O. Background Technology

[0002] With the acceleration of global industrialization, the massive consumption of fossil fuels has led to a continuous rise in atmospheric carbon dioxide (CO2) concentrations, triggering severe environmental problems such as global warming and extreme weather events. Simultaneously, the depletion of traditional energy reserves is driving the urgent development of sustainable energy conversion technologies. Against this backdrop, electrocatalytic CO2 reduction reaction (CO2RR), with its unique advantages of being driven by renewable electricity, having easily controllable products, and achieving a "carbon cycle," has become a promising approach for converting CO2 into high-value-added, multi-carbon (C2) products such as ethylene and ethanol. 2+ The core technology direction of chemical products provides an important solution for alleviating the dual crises of environment and energy. Among many CO2RR catalysts, copper (Cu)-based materials stand out because they can break the C-C coupling energy barrier in CO2 reduction, enabling the conversion from C1 intermediates to C2. 2+ The conversion of products has made it the only metal catalyst currently capable of efficiently generating multi-carbon products, and it is widely considered one of the most promising CO2RR catalytic systems; however, its adsorption strength for key intermediates is difficult to control, it easily generates C1 products such as CO or methane, and its stability is poor. Silver (Ag) can efficiently catalyze the conversion of CO2 to CO and inhibit the hydrogen evolution reaction. By constructing a heterostructure with Cu, it can promote the migration of *CO to Cu sites and enhance C-C coupling. In addition, halide ions (such as Br₂) can also be used to catalyze the conversion of CO2 to CO. - Doping with α can further regulate the microenvironment and electronic structure of the catalyst surface, suppress hydrogen evolution side reactions, and optimize the reaction pathway, but its mechanism of action in the Ag-Cu system is still unclear.

[0003] A search revealed that in the field of copper-based catalysts for improving the electroreduction of CO2 to multi-carbon products, existing technologies have explored optimizing reaction pathways by constructing copper-silver heterostructures. For example, patent application CN202111337226.7 discloses a method for preparing an Ag@Cu2O core-shell nanosphere catalyst. This catalyst uses silver nanospheres as the core and porous cuprous oxide as the shell, achieving tandem catalysis between copper and silver through the core-shell structure. This increases the interfacial contact area to promote electron transfer, and the coating structure exposes more copper active sites, thereby promoting the adsorption of *CO intermediates and CC coupling, improving selectivity for multi-carbon products. 2+The Faraday efficiency can reach up to 74.4%. Its preparation method specifically includes: 1) reducing silver salt in PVA aqueous solution to obtain a silver nanosphere dispersion; 2) adding copper salt to the dispersion and changing its copper-silver ratio, reducing again, and obtaining core-shell structured catalysts with different copper-silver ratios after centrifugation, washing, and drying. Although this catalyst significantly improves the selectivity for multi-carbon products, the core-shell structured catalyst and its preparation method still have certain limitations. On the one hand, its synthesis requires stepwise steps, and the process is relatively cumbersome, which is not conducive to large-scale production; on the other hand, its core-shell morphology may cause some silver active sites to be completely coated, limiting the efficiency of silver in providing *CO in continuous reactions.

[0004] Therefore, it is necessary to develop highly selective C2O3 with high efficiency, stability, and ease of preparation. 2+ Product catalysts are of vital importance for promoting the industrial application of electrocatalytic CO2 reduction to produce high-value-added chemicals. Summary of the Invention

[0005] Regarding the existing technology of copper-based catalysts for the reduction of carbon dioxide to C 2+ The present invention addresses the problems of low product selectivity, high reaction overpotential, and easy catalyst remodeling. It employs a simple one-pot solvothermal reduction method. First, a precursor solution is formed by mixing silver and copper salts in an aqueous solution of hexadecyltrimethylammonium bromide (CTAB). Then, a one-pot reaction is carried out via ascorbic acid reduction and alkaline precipitation to directly prepare an Ag / AgBr / Cu₂O heterostructure nanocatalyst, which can be used as a catalyst for the electrochemical reduction of carbon dioxide to C₂. 2+ The product serves as an electrode catalyst. The above preparation method requires only simple heating and stirring equipment, has a simple operation process, mild reaction conditions, is suitable for scale-up production, and meets the requirements of green and sustainable development. The Ag / AgBr / Cu2O catalyst prepared by this method contains a metal multi-element heterojunction and a bromine component; these three components significantly improve the C2O content through synergistic effects. 2+ The high selectivity of the product (up to 82.7%) reduces the Faraday efficiency of hydrogen, but has good application prospects.

[0006] A type with high C 2+ A method for preparing the selective carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O includes the following steps:

[0007] (1) Dissolve the silver salt and copper salt separately in an aqueous solution of a surfactant and stir until completely dissolved to obtain a precursor solution;

[0008] (2) The reducing agent is dissolved in water and mixed with the precursor solution to carry out a co-reduction reaction. An alkaline solution is added during the reaction. After the reaction is completed, the carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O is obtained through post-treatment.

[0009] In step (1) above:

[0010] Preferably, the silver salt is silver nitrate.

[0011] Preferably, the copper salt is copper sulfate pentahydrate.

[0012] Preferably, the molar ratio of silver salt to copper salt is (0.2~0.4):1. More preferably, it is 0.3:1.

[0013] Preferably, the surfactant is hexadecyltrimethylammonium bromide (CTAB).

[0014] Preferably, the concentration of the surfactant aqueous solution is 0.05~0.2 mol / L. More preferably, it is 0.1 mol / L.

[0015] Preferably, the molar ratio of copper salt to surfactant is (0.01~0.03):1. More preferably, it is 0.02:1.

[0016] Preferably, the stirring and dissolving are carried out under heating conditions, with a heating temperature of 35 to 45 °C. More preferably, it is 40 °C.

[0017] Preferably, the stirring speed is 500~1000 rpm. More preferably, it is 600 rpm.

[0018] In step (2) above:

[0019] As a preferred reducing agent, ascorbic acid (AA) is used.

[0020] Preferably, the molar ratio of the reducing agent to the copper salt is (4~6):1. More preferably, it is 5.1:1.

[0021] Preferably, the alkaline solution is an aqueous solution of sodium hydroxide (NaOH).

[0022] Preferably, the concentration of the alkaline solution is 0.15 ~ 0.25 mmol / L. More preferably, it is 0.2 mmol / L.

[0023] Preferably, the molar ratio of copper salt to alkali in the alkaline solution is 1:(0.005~0.02). More preferably, it is 1:0.01.

[0024] Preferably, the co-reduction reaction after adding the reducing agent is carried out at a temperature of 55-65 °C. More preferably, it is 58-62 °C. As an even more preferred option, the reaction temperature is 60 °C.

[0025] Preferably, the alkaline solution is added after the co-reduction reaction has proceeded for 15 to 25 minutes. More preferably, it is carried out for 18 to 22 minutes. Even more preferably, it is carried out for 20 minutes.

[0026] Preferably, the reaction temperature after adding the alkaline solution is 55~65℃. More preferably, it is 60℃.

[0027] Preferably, the reaction time after adding the alkaline solution is 8-12 minutes. More preferably, it is 10 minutes.

[0028] Preferably, after the reaction with added alkaline solution is complete, the following post-treatment is performed:

[0029] The reaction solution was centrifuged, and the obtained product was washed by centrifugation with a mixed solution of ethanol and deionized water, and then vacuum dried to obtain the carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O.

[0030] As a further preferred embodiment, in the mixed solution of ethanol and deionized water, the volume ratio of ethanol to deionized water is 1:(1~3). Even more preferred is 1:2.

[0031] As a further preferred option, the centrifugation speed for the reaction solution is 8000~12000 rpm, and the centrifugation time is 3~7 min. As an even more preferred option, the centrifugation speed is 10000 rpm, and the centrifugation time is 5 min.

[0032] As a further preferred option, the drying process is carried out in a vacuum oven at a temperature of 55–65 °C for 3–7 h. Even more preferred is a drying temperature of 60 °C for 5 h.

[0033] The present invention also provides a high C 2+ The selective carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O is prepared by any of the methods described above. The carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O of the present invention, when applied in the carbon dioxide electroreduction reaction, exhibits high Cg content. 2+ With product selectivity (up to 82.7%) and low hydrogen Faraday efficiency, it is suitable for using renewable electricity to convert greenhouse gas carbon dioxide into high-value-added multi-carbon chemicals such as ethylene and ethanol, providing key technological support for achieving carbon cycle and sustainable energy development.

[0034] The present invention also provides the above-mentioned high C 2+ Application of selective carbon dioxide electroreduction catalysts Ag / AgBr / Cu2O in the electrocatalytic reduction of carbon dioxide.

[0035] Specifically, the Ag / AgBr / Cu2O catalyst is sprayed onto the surface of a gas diffusion electrode and used as the working electrode. A flow electrolytic cell is used, with a silver / silver chloride (Ag / AgCl) electrode as the reference electrode, nickel foam as the counter electrode, and potassium hydroxide (KOH) solution as the electrolyte, to carry out the electrocatalytic reduction of carbon dioxide.

[0036] Preferably, the concentration of the potassium hydroxide (KOH) solution in the electrolyte is 0.5~2 mol / L. More preferably, it is 1 mol / L.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] (1) The present invention has high C 2+ A selective Ag / AgBr / Cu2O catalyst preparation method employs a one-pot solvothermal reduction process. This method features a simple flow, mild reaction conditions (≤60℃), and requires only conventional heating and stirring equipment, avoiding complex high-temperature and high-pressure processes. The reagents used are inexpensive and environmentally friendly, and the entire preparation process meets the requirements of green chemistry, demonstrating good reproducibility and potential for large-scale production.

[0039] (2) The present invention has high C 2+ The selective Ag / AgBr / Cu2O catalyst exhibits excellent electrocatalytic CO2 reduction performance in an alkaline flow electrolyzer, displaying extremely high selectivity for multi-carbon products. The optimal catalyst at -1.0 V (vs. RHE) shows C2... 2+ The product's Faraday efficiency can reach up to 82.7%, while C 2+ The local current density of the product is as high as 121.7 mA·cm. -2 .

[0040] (3) The present invention has high C 2+ A selective Ag / AgBr / Cu₂O catalyst and its preparation method are presented for the first time, combining metallic Ag, AgBr, and Cu₂O, and experimental results confirm a significant synergistic effect among the three. Specifically, the Ag site efficiently generates the *CO intermediate, and the Br₂O in AgBr... - The component not only optimizes the electronic structure of the catalyst surface and enhances the adsorption and stability of CO intermediates, but more importantly, it significantly lowers the reaction energy barrier for the key steps of *CO hydrogenation to *CHO and subsequent CC coupling, thereby greatly promoting C… 2+ The product generation path.

[0041] The preparation method and product of this invention provide new ideas for designing high-performance CO2 conversion catalysts, and have significant scientific value and industrial application potential. Attached Figure Description

[0042] Figure 1 The XRD patterns are shown for the Cu2O NPs, pm-Ag / Cu2O, and Ag / AgBr / Cu2O catalysts prepared in Comparative Example 1, Comparative Example 2, and Example 1.

[0043] Figure 2 The image shows a SEM image of the Ag / AgBr / Cu2O catalyst prepared in Example 1.

[0044] Figure 3 The image shows the EDS elemental distribution of the Ag / AgBr / Cu2O catalyst prepared in Example 1.

[0045] Figure 4 The graph shows the electrochemical carbon dioxide reduction performance of the Ag / AgBr / Cu2O catalyst prepared in Example 1.

[0046] Figure 5 The image shows a SEM image of the Cu2O catalyst prepared in Comparative Example 1.

[0047] Figure 6 The graph shows the electrochemical carbon dioxide reduction performance of the Cu2O catalyst prepared in Comparative Example 1.

[0048] Figure 7 TEM image of the pm-Ag / Cu2O catalyst prepared in Comparative Example 2;

[0049] Figure 8 The graph shows the electrochemical reduction performance of carbon dioxide by the pm-Ag / Cu2O catalyst prepared in Comparative Example 2. Detailed Implementation

[0050] The present invention will be further described in detail below through specific embodiments.

[0051] Example 1:

[0052] (1) Preparation of precursor solution: Dissolve 0.0102 g (0.06 mmol) silver nitrate and 0.05 g (0.2 mmol) copper sulfate pentahydrate in 100 mL (containing 0.01 mol CTAB) hexadecyltrimethylammonium bromide aqueous solution, heat to 40 °C and stir at 600 rpm until completely dissolved to obtain S1 solution (precursor solution) for later use.

[0053] Preparation of reducing agent solution: Dissolve 0.18 g (1.02 mmol) of ascorbic acid in 10 mL of deionized water to obtain S2 solution.

[0054] (2) Synthesis of Ag / AgBr / Cu2O heterostructure catalyst: Under oil bath conditions of 40℃, the above S2 solution was added to the S1 solution, the temperature was raised to 60℃ and maintained at this temperature for 20 min. Then, 10 mL of sodium hydroxide solution (containing 0.002 mmol NaOH) was added dropwise to the system, and a gray-green precipitate was observed to form. The reaction was continued at 60℃ for 10 min. After the reaction was completed, the product was collected by centrifugation and separated by centrifugation 4 to 5 times with a mixed solution of ethanol and deionized water (the volume ratio of ethanol to deionized water was 1:2) at a speed of 10000 rpm for 5 min. Finally, the washed product was dried in a vacuum drying oven at 60℃ for 5 h to obtain the Ag / AgBr / Cu2O catalyst.

[0055] Structural characterization:

[0056] X-ray diffraction (XRD) analysis was performed on the Ag / AgBr / Cu2O catalyst prepared in Example 1 above, and the results are as follows: Figure 1 As shown. By Figure 1 It can be seen that the diffraction peaks at 36.4° and 42.3° in the XRD pattern of Ag / AgBr / Cu2O nanoparticles correspond to the (111) and (200) crystal planes of cubic Cu2O, respectively. The diffraction peaks at 38.1° and 44.3° correspond to the (111) and (200) crystal planes of face-centered cubic Ag, respectively. Furthermore, the diffraction peak of Ag / AgBr / Cu2O at 30.96° corresponds to the (200) crystal plane of AgBr, indicating that AgBr was successfully generated during the synthesis process.

[0057] Figure 2 The above-prepared Ag / AgBr / Cu2O catalyst is shown in the SEM image. Figure 2 It can be seen that the prepared Ag / AgBr / Cu2O has a unique heterostructure nanosphere morphology, in which Cu2O nanospheres with a size of about 250 nm serve as the substrate, and multiple Ag / AgBr nanoparticles with a size of about 40 nm and a rough surface are uniformly attached to their surface.

[0058] Figure 3 The EDS elemental distribution diagram of the Ag / AgBr / Cu2O catalyst prepared above is shown below. Figure 3 It can be seen that the four elements Cu, Ag, Br and O are clearly distributed in the heterostructured nanospheres. The signals of Cu and O elements originate from Cu2O nanospheres, while the signals of Ag and Br elements are highly overlapping and mainly concentrated on the external attached particles, which confirms the successful formation of AgBr and its recombination with Cu2O.

[0059] application:

[0060] The Ag / AgBr / Cu2O catalyst was sprayed onto the surface of a gas diffusion electrode using a spray gun and used as the working electrode. Electrocatalytic performance of carbon dioxide was tested using a three-electrode system. Simultaneously, a flow electrolyzer was employed, with nickel foam as the counter electrode and a silver / silver chloride electrode (Ag / AgCl) as the reference electrode. The cathode and anode chambers were separated by a cation exchange membrane (Nafion 117), and the electrolyte was a 1 mol / L KOH solution. The resulting gaseous products were detected by gas chromatography (GC), and the liquid products were analyzed using... 1 H-nuclear magnetic resonance (NMR) 1 H-NMR) detection.

[0061] Figure 4 The electrocatalytic performance of the Ag / AgBr / Cu2O catalyst prepared above in the voltage range of -0.8 ~ -1.4 V (vs. RHE) for carbon dioxide can be seen from the results. 2+ The product exhibits high selectivity while effectively suppressing the hydrogen evolution side reaction. Specifically, under -1.0 V (vs. RHE) conditions, C 2+ The product exhibits a Faraday efficiency of 82.7%, corresponding to a local current density of 121.7 mA·cm⁻¹. -2 The Faraday efficiency of hydrogen is only 7.8%. At -1.3 V (vs. RHE), C 2+ The local current density reached a maximum of 168.2 mA·cm. -2 .

[0062] Comparative Example 1:

[0063] (1) Preparation of precursor solution: Dissolve 0.05 g (0.2 mmol) copper sulfate pentahydrate in 100 mL (containing 0.01 mol CTAB) hexadecyltrimethylammonium bromide aqueous solution, heat to 40 °C and stir at 600 rpm until completely dissolved to obtain S1 solution, which is ready for use.

[0064] (2) Preparation of reducing agent solution: Dissolve 0.18 g (1.02 mmol) of ascorbic acid in 10 mL of deionized water to obtain S2 solution.

[0065] (3) Synthesis of Cu2O catalyst: Under oil bath conditions of 40℃, the above S2 solution was added to the S1 solution, the temperature was raised to 60℃ and maintained at this temperature for 20 min. Then, 10 mL of sodium hydroxide solution (containing 0.002 mmol NaOH) was added dropwise to the system, and a yellow precipitate was observed to form. The reaction was continued at 60℃ for 10 min. After the reaction was completed, the product was collected by centrifugation and separated by centrifugation 4 to 5 times with a mixed solution of ethanol and deionized water (the volume ratio of ethanol to deionized water was 1:2) at a speed of 10000 rpm for 5 min. Finally, the washed product was dried in a vacuum drying oven at 60℃ for 5 h to obtain pure Cu2O NPs.

[0066] Figure 5 The morphology and structure diagram of Cu2O NPs are shown below. Figure 5 It can be seen that Cu₂O NPs exhibit a highly uniform three-dimensional spherical structure with a narrow particle size distribution and an average diameter of approximately 180 nm. These nanospheres have smooth surfaces and regular morphologies, which contrasts sharply with the heterogeneous structure formed after the introduction of Ag.

[0067] application:

[0068] The Cu₂O NPs catalyst was sprayed onto the surface of a gas diffusion electrode using a spray gun and used as the working electrode. Electrocatalytic performance of carbon dioxide was tested using a three-electrode system. Simultaneously, a flow electrolytic cell was employed, with nickel foam as the counter electrode and a silver / silver chloride electrode (Ag / AgCl) as the reference electrode. The cathode and anode chambers were separated by a cation exchange membrane (Nafion 117), and the electrolyte was a 1 mol / L KOH solution. The obtained gaseous products were detected by gas chromatography (GC), and the liquid products were analyzed using... 1 H-nuclear magnetic resonance (NMR) 1 H-NMR) detection.

[0069] Figure 6 The electrocatalytic performance of Cu2O NPs for carbon dioxide in the voltage range of -0.8 ~ -1.4V (vs. RHE) shows that it is comparable to that of Ag / AgBr / Cu2O ( Figure 4 Compared to Cu2O NPs, the C 2+ The product selectivity was lower than that of Ag / AgBr / Cu2O throughout the entire test potential window, accompanied by a relatively significant hydrogen evolution side reaction. Specifically, under -1.2 V (vs. RHE) conditions, C 2+ The highest Faraday efficiency was 65.0% for the product and 9.7% for hydrogen, indicating that the Cu2O NPs catalyst exhibits good performance for C. 2+ The product's selectivity and ability to suppress the hydrogen evolution reaction are limited, further indicating that the introduction of Ag and the doping of Br synergistically promote C2+ Product formation.

[0070] Comparative Example 2:

[0071] (1) Preparation of precursor solution: Dissolve 0.05 g (0.2 mmol) copper sulfate pentahydrate in 100 mL (containing 0.01 mol CTAB) hexadecyltrimethylammonium bromide aqueous solution, heat to 40 °C and stir at 600 rpm until completely dissolved to obtain S1 solution, which is ready for use.

[0072] (2) Preparation of reducing agent solution: Dissolve 0.18 g (1.02 mmol) of ascorbic acid in 10 mL of deionized water to obtain S2 solution.

[0073] (3) Synthesis of Cu2O catalyst: Under oil bath conditions of 40℃, the above S2 solution was added to the S1 solution, the temperature was raised to 60℃ and maintained at this temperature for 20 min. Then, 10 mL of sodium hydroxide solution (containing 0.002 mmol NaOH) was added dropwise to the system, and a yellow precipitate was observed to form. The reaction was continued at 60℃ for 10 min. After the reaction was completed, the product was collected by centrifugation and separated by centrifugation 4 to 5 times with a mixed solution of ethanol and deionized water at a speed of 10000 rpm for 5 min. Finally, the washed product was dried in a vacuum drying oven at 60℃ for 5 h to obtain pure Cu2O catalyst.

[0074] (4) Preparation of Ag / Cu2O physical mixture: 2.7 mg of silver powder and 7.3 mg of pure Cu2O catalyst were physically mixed, ultrasonicated with ethanol for 10 min, and after mixing evenly, the product was collected by centrifugation. The mixture was then centrifuged 4 to 5 times with a mixed solution of ethanol and deionized water (the volume ratio of ethanol to deionized water was 1:2) at a speed of 10,000 rpm for 5 min. Finally, the washed product was dried in a vacuum drying oven at 60℃ for 5 h to obtain the Ag / Cu2O physical mixture pm-Ag / Cu2O.

[0075] Figure 7 The image shows a TEM image of the pm-Ag / Cu2O catalyst prepared in Comparative Example 2 above. The TEM image reveals a clear physical gap between the commercial Ag nanoparticles (silver powder) and the Cu2O nanospheres, lacking a tight interfacial bond. This contrasts sharply with the Ag / AgBr / Cu2O catalyst, further demonstrating its physically mixed nature.

[0076] Application: The above-mentioned pm-Ag / Cu2O catalyst was sprayed onto the surface of a gas diffusion electrode using a spray gun and used as the working electrode. Electrocatalytic performance of carbon dioxide was tested using a three-electrode system. Simultaneously, a flow electrolyzer was employed, with nickel foam as the counter electrode and a silver / silver chloride electrode (Ag / AgCl) as the reference electrode. The cathode and anode chambers were separated by a cation exchange membrane (Nafion 117), and the electrolyte was a 1 mol / L KOH solution. The obtained gaseous products were detected by gas chromatography (GC), and the liquid products were analyzed using... 1 H-nuclear magnetic resonance (NMR) 1 H-NMR) detection.

[0077] Figure 8 The electrocatalytic performance of pm-Ag / Cu2O catalyst for carbon dioxide in the voltage range of -0.8 to -1.4 V (vs. RHE) shows that compared with pure Cu2O NPs, its hydrogen evolution reaction (HER) is effectively suppressed, and the hydrogen Faradaic efficiency is less than 10%. However, under the condition of -1.4 V (vs. RHE), its C 2+ The product achieved a maximum Faraday efficiency of 71.0%, which, while better than the highest value of pure Cu₂O, is significantly lower than that of the Ag / AgBr / Cu₂O catalyst (82.7%). This result indicates that simply introducing Ag can suppress hydrogen evolution and locally increase C₂ efficiency. 2+ It exhibits product selectivity but lacks the regulatory effect of Br, thus failing to maximize CC coupling efficiency.

Claims

1. A type of high C 2+ A method for preparing a selective carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O, characterized in that, Includes the following steps: (1) Dissolve the silver salt and copper salt separately in an aqueous solution of a surfactant and stir until completely dissolved to obtain a precursor solution; (2) The reducing agent is dissolved in water and mixed with the precursor solution to carry out a co-reduction reaction. An alkaline solution is added during the reaction. After the reaction is completed, the carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O is obtained through post-treatment.

2. The high C content according to claim 1 2+ A method for preparing a selective carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O, characterized in that, The silver salt is silver nitrate; The copper salt is copper sulfate pentahydrate; The molar ratio of silver salt to copper salt is (0.2~0.4):

1.

3. The high C content according to claim 1 2+ A method for preparing a selective carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O, characterized in that, The surfactant is hexadecyltrimethylammonium bromide; The molar ratio of copper salt to surfactant is (0.01~0.03):

1.

4. The high C content according to claim 1 2+ A method for preparing a selective carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O, characterized in that, The reducing agent is ascorbic acid; The molar ratio of reducing agent to copper salt is (4~6):

1.

5. The high C content according to claim 1 2+ A method for preparing a selective carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O, characterized in that, The alkaline solution is an aqueous solution of sodium hydroxide; The molar ratio of copper salt to alkali in the alkaline solution is 1:(0.005~0.02).

6. The high C content according to claim 1 2+ A method for preparing a selective carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O, characterized in that, In step (2), the reaction temperature of the co-reduction reaction after adding the reducing agent is 55 ~ 65 ℃; the alkaline solution is added after the co-reduction reaction has been carried out for 15 ~ 25 min.

7. The high C content according to claim 1 2+ A method for preparing a selective carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O, characterized in that, The reaction temperature after adding the alkaline solution is 55~65℃; the reaction time is 8~12min.

8. The high C content according to claim 1 2+ A method for preparing a selective carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O, characterized in that, In step (2), after the reaction with added alkaline solution is complete, the following post-treatment is performed: The reaction solution was centrifuged, and the obtained product was washed by centrifugation with a mixed solution of ethanol and deionized water, and then vacuum dried to obtain the carbon dioxide electroreduction catalyst.

9. A type of high C 2+ The selective carbon dioxide electroreduction catalyst Ag / AgBr / Cu2O is characterized by, It is prepared by the preparation method according to any one of claims 1 to 8.

10. A high C as described in claim 9 2+ Application of selective carbon dioxide electroreduction catalysts Ag / AgBr / Cu2O in the electrocatalytic reduction of carbon dioxide.

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