Indium-doped copper oxide electrode for electrocatalytic reduction of co2 and method for preparing the same
By doping indium into the copper oxide lattice, indium-doped copper oxide electrodes were prepared, solving the problems of complex catalyst products and high cost, and achieving the effect of highly selective reduction of CO2 to carbon monoxide.
Patent Information
- Application Number
- CN202411955865.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-28
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2044-12-28
AI Technical Summary
Existing catalysts produce complex products during the electrocatalytic reduction of CO2, making it difficult to selectively reduce a single product, and the use of precious metals increases costs.
Indium-doped copper oxide electrodes were prepared by doping indium into a copper oxide lattice, using copper chloride and indium nitrate as precursors, combined with sodium hydroxide as a precipitant, co-precipitating, heating and decomposing, centrifuging, washing and vacuum drying, and preparing a mixed ink which was then coated onto carbon paper.
This improved the stability and selectivity of the catalyst, suppressed the generation of competing product hydrogen, and reduced the preparation cost, thus achieving efficient electrocatalytic reduction of CO2 to carbon monoxide.
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Figure CN119663300B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electrocatalytic reduction technology, and in particular to an indium-doped copper oxide electrode for electrocatalytic reduction of CO2 and its preparation method. Background Technology
[0002] Since the beginning of the 21st century, the excessive use of fossil fuels has not only caused energy shortages but also led to a year-on-year increase in atmospheric carbon dioxide (CO2) levels, resulting in a series of harms such as the greenhouse effect and acid rain. Therefore, exploring new, alternative, and environmentally friendly energy sources and systems is of paramount importance. Currently, utilizing carbon dioxide reduction reactions to generate high-value-added energy products and forming a carbon cycle within a certain scope has broad application prospects. Carbon dioxide reduction includes photocatalysis, electrochemical catalysis, photoelectrocatalysis, and chemical conversion. Among these, electrochemical catalytic reduction technology has attracted extensive research, mainly because: 1) the operating conditions of electrocatalytic systems are relatively mild and do not cause environmental pollution; 2) by designing the catalyst and changing the reduction voltage, the types of catalytic products can be effectively controlled and the selectivity of products improved; 3) current technology can convert renewable and clean energy sources such as solar, wind, and tidal energy into electricity and can supply it in a timely manner by peak shaving.
[0003] The numerous reduction products of CO2 pose significant challenges to the separation of subsequent products, making it imperative to improve the selectivity and activity for specific products. Among these products, carbon monoxide (CO) offers the highest economic benefits and is a crucial raw material in Fischer-Tropsch synthesis. Copper has garnered widespread attention due to its excellent performance and low price; however, copper products are highly complex, making it difficult to obtain a single reduction product. Current techniques typically employ Au, Ag, and Cu to construct a two-phase interface, which not only yields less than optimal performance but also significantly increases the cost of electrolytic preparation due to the use of precious metals. By doping indium atoms into the copper oxide lattice, the adsorption of the intermediate *COOH can be enhanced while the adsorption of *CO can be reduced, significantly improving performance and greatly reducing electrode fabrication costs. Therefore, constructing an indium-doped copper oxide electrode material has significant economic and social implications. Summary of the Invention
[0004] The purpose of this invention is to provide an indium-doped copper oxide electrode for the electrocatalytic reduction of CO2 and its preparation method, solving the problem that existing catalysts have difficulty in selectively reducing a single product due to the complexity of CO2 reduction products. This invention, by adding indium, not only effectively suppresses hydrogen production but also improves the stability of the entire catalytic process. Therefore, constructing an indium-doped copper oxide electrode material has significant economic and social implications. The indium-doped copper oxide electrode for the electrocatalytic reduction of CO2 of this invention uses copper chloride and indium nitrate as precursors and sodium hydroxide as a precipitant. The precursor is co-precipitated, followed by vigorous stirring, heating and decomposition, centrifugation, washing, and vacuum drying to obtain the indium-doped copper oxide catalyst. A mixed ink is prepared by adding ethanol, water, and naphthol solution, which is then uniformly coated onto carbon paper and dried to obtain the indium-doped copper oxide electrode.
[0005] The above-mentioned objective of the present invention is achieved through the following technical solution:
[0006] A method for preparing an indium-doped copper oxide electrode for electrocatalytic reduction of CO2 includes the following steps:
[0007] Step (1) Take 25 mL of deionized water, add 1.785 g of copper chloride dihydrate to prepare a copper chloride aqueous solution, place it in a water bath and stir until completely dissolved;
[0008] Step (2) Prepare 25 mL of indium nitrate solution and add it dropwise to the reaction solution in step (1) under vigorous stirring. Stir at 30°C for 30 min.
[0009] Prepare 40 mL of sodium hydroxide solution. At a constant temperature of 30 °C, slowly add the sodium hydroxide solution dropwise to a mixed solution of copper chloride and indium nitrate while stirring continuously. The solution gradually turns dark blue. Then, raise the temperature to 80 °C and stir at a constant temperature until the solution turns black. Stop the reaction after 3 hours. After the solution cools to room temperature, collect it by initial centrifugation, wash it three times with deionized water and anhydrous ethanol, and dry it in a vacuum drying oven to obtain the indium-doped copper oxide catalyst.
[0010] In step (3), ethanol, deionized water and 5% naphthol solution were mixed in a volume ratio of 10:10:1. 2 mg of the indium-doped copper oxide catalyst obtained in step (2) was added and ultrasonically treated to obtain mixed ink. The ink solution was uniformly coated on carbon paper that had been pre-cut to 1 cm × 1 cm. After drying, an indium-doped copper oxide catalytic electrode for electrochemical catalytic CO2 reduction was prepared.
[0011] The concentration of the copper chloride solution mentioned in step (1) is 0.02 mol / L.
[0012] The concentration of the sodium hydroxide solution mentioned in step (2) is 2 mol / L; the concentration of the indium nitrate solution is 0.0006 mol / L.
[0013] In step (2), the vacuum drying temperature is 70℃ and the drying time is 24h.
[0014] The drying process described in step (3) involves rapidly drying the coated carbon paper working electrode in an infrared drying oven.
[0015] The indium-doped copper oxide electrode for the electrocatalytic reduction of CO2 prepared in this invention improves the catalytic performance of the electrode by doping indium into the copper oxide lattice. The indium atom doping effectively enhances the catalyst kinetics and accelerates the desorption of CO from the catalyst surface. Furthermore, a small amount of indium doping increases the stability of the catalytic process while suppressing the generation of the competing product, hydrogen.
[0016] The beneficial effects of this invention are as follows:
[0017] (1) Doping copper oxide with a small amount of indium can effectively improve the performance of the catalyst without the need for other precious metals, and can effectively improve the kinetics of the catalyst.
[0018] (2) The catalyst electrode prepared by the present invention not only improves the stability of the electrode catalytic process by doping a small amount of indium atoms into copper, but also suppresses the generation of competing product hydrogen.
[0019] (3) The indium-doped copper oxide electrode for electrocatalytic reduction of CO2 prepared in this invention has high selectivity for the product carbon monoxide while also having a large current density.
[0020] (4) The preparation method of the indium-doped copper oxide electrode for electrocatalytic reduction of CO2 provided by the present invention has a simple operation process, the raw materials are easy to obtain, there is no pollution, no need for expensive equipment, and it has broad application prospects. Attached Figure Description
[0021] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate the invention and are used to explain it, but do not constitute an undue limitation of the invention.
[0022] Figure 1 The image shows a scanning electron microscope (SEM) image of the indium-doped copper oxide catalyst prepared in Example 1 of the present invention.
[0023] Figure 2 The EDX elemental energy spectrum of the indium-doped copper oxide catalyst prepared in Example 1 of the present invention;
[0024] Figure 3The XRD diffraction pattern of the silver-modified cuprous oxide catalyst prepared in Example 1 of the present invention;
[0025] Figure 4 The catalytic electrode prepared for Example 1 of the present invention is the working electrode, the platinum sheet is the counter electrode, and the silver / silver chloride is the reference electrode. The current density-voltage curve was obtained in an H-type electrolytic cell with 0.1 mol / L saturated potassium bicarbonate electrolyte, under the conditions of CO2 flow rate of 30 mL / min and scan rate of 10 mV / s.
[0026] Figure 5 Examples 1-4 of the present invention show the Faraday efficiency of the product carbon monoxide at -0.8V vs. RHE. Detailed Implementation
[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0028] See Figures 1 to 5 As shown, the indium-doped copper oxide electrode for the electrocatalytic reduction of CO2 and its preparation method of the present invention use copper chloride and indium nitrate as raw materials and sodium hydroxide as a precipitant to co-precipitate and obtain a precursor. This precursor is then decomposed by heating, centrifuged, washed, and vacuum dried to obtain an indium-doped copper oxide catalyst. An ink is prepared by mixing water, ethanol, and a naphthol solution, uniformly coated onto carbon paper, and dried to obtain the indium-doped copper oxide electrode. The prepared indium-doped copper oxide electrode exhibits high catalytic activity and good stability. The presence of indium atoms doped into the copper oxide lattice improves the catalyst kinetics, accelerates the desorption of carbon monoxide from the surface, and enhances catalyst stability while suppressing the generation of competing product hydrogen. The present invention features a simple operation process, readily available raw materials, no pollution, and requires no expensive equipment, thus possessing broad application prospects. Example 1
[0029] A method for preparing an indium-doped copper oxide electrode for electrocatalytic reduction of CO2 includes the following steps:
[0030] (1) Take 25 mL of deionized water, add 1.785 g of copper chloride dihydrate to prepare a copper chloride aqueous solution, place it in a water bath and heat to 30 °C;
[0031] (2) Take 15.04 mg of indium nitrate, add 25 mL of deionized water, and add it dropwise to the reaction solution in step (1) under vigorous stirring. Take 8 g of sodium hydroxide, add 40 mL of deionized water, and slowly add the sodium hydroxide solution to the mixed solution of copper chloride and indium nitrate at a constant temperature of 30 °C. Continue stirring for 30 min, and the solution gradually turns dark blue. Then, raise the temperature to 80 °C, and the solution turns black. Stir for another 3 h at a constant temperature, stop the reaction, and wait for the solution to cool to room temperature. After the initial centrifugation, wash the solution three times with deionized water and anhydrous ethanol, and dry it in a vacuum drying oven at 70 °C for 24 h to obtain the indium-doped copper oxide catalyst.
[0032] (3) Take 100 μL of ethanol, 100 μL of deionized water and 10 μL of 5% naphthol solution to prepare a mixed solution, add 2 mg of indium-doped copper oxide catalyst obtained in step (2), and sonicate for 2 h to obtain mixed ink; take 100 μL of ink solution, coat it evenly on carbon paper that has been pre-cut to 1 cm × 1 cm, and dry it quickly in an infrared drying oven to prepare an indium-doped copper oxide catalytic electrode for electrochemical catalytic CO2 reduction.
[0033] The resulting catalytic electrode exhibited a selectivity of up to 66% for carbon monoxide at -0.8V vs. RHE. Example 2
[0034] A method for preparing an indium-doped copper oxide electrode for electrocatalytic reduction of CO2 includes the following steps:
[0035] (1) Take 25 mL of deionized water, add 1.785 g of copper chloride dihydrate to prepare a copper chloride aqueous solution, place it in a water bath and heat to 30 °C;
[0036] (2) Take 45.12 mg of indium nitrate, add 25 mL of deionized water, and add it dropwise to the reaction solution in step (1) under vigorous stirring. Take 8 g of sodium hydroxide, add 40 mL of deionized water, and slowly add the sodium hydroxide solution to the mixed solution of copper chloride and indium nitrate at a constant temperature of 30°C. Continue stirring for 30 min, and the solution gradually turns dark blue. Then, raise the temperature to 80°C, and the solution turns black. Stir for another 3 h at a constant temperature, stop the reaction, and wait for the solution to cool to room temperature. After the initial centrifugation, wash the solution three times with deionized water and anhydrous ethanol, and dry it in a vacuum drying oven at 70°C for 24 h to obtain the indium-doped copper oxide catalyst.
[0037] (3) Take 100 μL of ethanol, 100 μL of deionized water and 10 μL of 5% naphthol solution to prepare a mixed solution, add 2 mg of indium-doped copper oxide catalyst obtained in step (2), and sonicate for 2 h to obtain mixed ink; take 100 μL of ink solution, coat it evenly on carbon paper that has been pre-cut 1 cm 1 cm, and dry it quickly in an infrared drying oven to prepare an indium-doped copper oxide catalytic electrode for electrochemical catalytic CO2 reduction.
[0038] The resulting catalytic electrode exhibited a selectivity of up to 95% for carbon monoxide at -0.8V vs. RHE. Example 3
[0039] A method for preparing an indium-doped copper oxide electrode for electrocatalytic reduction of CO2 includes the following steps:
[0040] (1) Take 25 mL of deionized water, add 1.785 g of copper chloride dihydrate to prepare a copper chloride aqueous solution, place it in a water bath and heat to 30 °C;
[0041] (2) Take 75.2 mg of indium nitrate, add 25 mL of deionized water, and add it dropwise to the reaction solution in step (1) under vigorous stirring. Take 8 g of sodium hydroxide, add 40 mL of deionized water, and slowly add the sodium hydroxide solution to the mixed solution of copper chloride and indium nitrate at a constant temperature of 30 °C. Continue stirring for 30 min, and the solution gradually turns dark blue. Then, raise the temperature to 80 °C, and the solution turns black. Stir for another 3 h at a constant temperature, stop the reaction, and wait for the solution to cool to room temperature. After the initial centrifugation, wash the solution three times with deionized water and anhydrous ethanol, and dry it in a vacuum drying oven at 70 °C for 24 h to obtain the indium-doped copper oxide catalyst.
[0042] (3) Take 100 μL of ethanol, 100 μL of deionized water and 10 μL of 5% naphthol solution to prepare a mixed solution, add 2 mg of indium-doped copper oxide catalyst obtained in step (2), and sonicate for 2 h to obtain mixed ink; take 100 μL of ink solution, coat it evenly on carbon paper that has been pre-cut to 1 cm × 1 cm, and dry it quickly in an infrared drying oven to prepare an indium-doped copper oxide catalytic electrode for electrochemical catalytic CO2 reduction.
[0043] The resulting catalytic electrode exhibited a selectivity of up to 79% for carbon monoxide at -0.8V vs. RHE. Example 4
[0044] A method for preparing an indium-doped copper oxide electrode for electrocatalytic reduction of CO2 includes the following steps:
[0045] (1) Take 25 mL of deionized water, add 1.785 g of copper chloride dihydrate to prepare a copper chloride aqueous solution, place it in a water bath and heat to 30 °C;
[0046] (2) Take 150.4 mg of indium nitrate, add 25 mL of deionized water, and add it dropwise to the reaction solution in step (1) under vigorous stirring. Take 8 g of sodium hydroxide, add 40 mL of deionized water, and slowly add the sodium hydroxide solution to the mixed solution of copper chloride and indium nitrate at a constant temperature of 30 °C. Continue stirring for 30 min, and the solution gradually turns dark blue. Then, raise the temperature to 80 °C, and the solution turns black. Stir for another 3 h at a constant temperature, stop the reaction, and wait for the solution to cool to room temperature. After the initial centrifugation, wash the solution three times with deionized water and anhydrous ethanol, and dry it in a vacuum drying oven at 70 °C for 24 h to obtain the indium-doped copper oxide catalyst.
[0047] (3) Take 100 μL of ethanol, 100 μL of deionized water and 10 μL of 5% naphthol solution to prepare a mixed solution, add 2 mg of indium-doped copper oxide catalyst obtained in step (2), and sonicate for 2 h to obtain mixed ink; take 100 μL of ink solution, coat it evenly on carbon paper that has been pre-cut to 1 cm × 1 cm, and dry it quickly in an infrared drying oven to prepare an indium-doped copper oxide catalytic electrode for electrochemical catalytic CO2 reduction.
[0048] The resulting catalytic electrode exhibited a selectivity of up to 72% for carbon monoxide at -0.8V vs. RHE.
[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made to the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing an indium-doped copper oxide electrode for electrocatalytic reduction of CO2, characterized in that: Includes the following steps: Step 1: Take 25 mL of deionized water, add 1.785 g of copper chloride dihydrate to prepare a copper chloride aqueous solution, place it in a water bath and stir until completely dissolved; Step 2: Prepare 25 mL of indium nitrate solution, add it dropwise to the reaction solution in Step 1 under vigorous stirring, heat to 30 °C, and continue stirring for 30 min; Prepare 40 mL of sodium hydroxide solution. At a constant temperature of 30 °C, slowly add the sodium hydroxide solution dropwise to a mixed solution of copper chloride and indium nitrate while stirring continuously. The solution gradually turns dark blue. When heated to 80 °C, the solution turns black. Stir continuously at 80 °C for 3 hours and then stop the reaction. After the solution cools to room temperature, collect it by initial centrifugation, wash it three times with deionized water and anhydrous ethanol respectively, and dry it in a vacuum drying oven to obtain indium-doped copper oxide catalyst. Step 3: Prepare a mixed solution by mixing ethanol, deionized water and 5% naphthol solution in a volume ratio of 10:10:1, add 2 mg of indium-doped copper oxide catalyst obtained in step 2, and sonicate to obtain mixed ink; uniformly coat the mixed ink solution on 1 cm × 1 cm carbon paper, and dry it to prepare an indium-doped copper oxide catalytic electrode for electrochemical catalytic CO2 reduction.
2. The method for preparing the indium-doped copper oxide electrode for electrocatalytic reduction of CO2 according to claim 1, characterized in that: The concentration of the copper chloride solution mentioned in step (1) is 0.02 mol / L.
3. The method for preparing the indium-doped copper oxide electrode for electrocatalytic reduction of CO2 according to claim 1, characterized in that: The concentration of the sodium hydroxide solution mentioned in step (2) is 2 mol / L; the concentration of the indium nitrate solution is 0.0006 mol / L.
4. The method for preparing the indium-doped copper oxide electrode for electrocatalytic reduction of CO2 according to claim 1, characterized in that: In step (2), the vacuum drying temperature is 70℃ and the drying time is 24h.
5. The method for preparing the indium-doped copper oxide electrode for electrocatalytic reduction of CO2 according to claim 1, characterized in that: The drying process described in step (3) involves rapidly drying the coated carbon paper working electrode in an infrared drying oven.
6. An indium-doped copper oxide electrode for electrocatalytic reduction of CO2 obtained by the preparation method according to any one of claims 1-5, characterized in that: The electrode material exhibits a Faraday efficiency of 94–96% for carbon monoxide at a potential of -0.8 V vs. RHE.