Supported catalysts, methods of making and using the same, gas diffusion electrodes, methods of making the same, and methods of carbon dioxide reduction

Abstract

The application discloses a supported catalyst, wherein a carrier of the supported catalyst comprises copper-BTC, and an active component comprises copper clusters; the copper clusters / copper-BTC of the supported catalyst is used as an electrocatalyst to activate carbon dioxide gas and reduce a reaction energy barrier of a key intermediate, exhibits high activity and selectivity on electrocatalytic reduction of the carbon dioxide into multi-carbon products, and a preparation method of the supported catalyst is environment-friendly and easy to control, has the advantages of short reaction period, high yield, low cost, stable product quality and uniform morphology, and also provides a new way for a carbon dioxide electrochemical reduction system.

Description

Technical Field

[0001] This invention relates to the field of carbon neutrality technology, specifically to a supported catalyst and its preparation method and application, a gas diffusion electrode and its preparation method, and a method for carbon dioxide reduction. Background Technology

[0002] The global carbon balance is being affected, causing environmental problems and jeopardizing sustainable development. To alleviate the energy crisis and environmental issues, it is necessary to develop and utilize clean energy. The ever-increasing carbon dioxide emissions into the ambient atmosphere have led to worsening global warming and ocean acidification. The global carbon balance is being affected, causing environmental problems and jeopardizing sustainable development. To alleviate the energy crisis and environmental issues, it is necessary to develop and utilize clean energy.

[0003] Over the past few decades, carbon dioxide conversion has been considered an effective way to reduce atmospheric carbon dioxide concentration, aiming to sustain the carbon cycle of ecosystems. Inspired by natural photosynthesis, capturing and utilizing carbon dioxide through chemical reaction pathways has become a research hotspot in recent years, with advanced technologies and well-designed catalysts attracting widespread attention to maximize carbon dioxide conversion efficiency. Electricity, as a clean and renewable energy source, can drive carbon dioxide reduction reactions under mild reaction conditions (i.e., room temperature and ambient pressure) to achieve the production of value-added chemicals from carbon dioxide. Notably, carbon dioxide, as an inert molecule, requires an excess of energy input for activation, thus necessitating highly efficient catalysts to provide that activity. Furthermore, current carbon dioxide electroreduction reaction systems still face various problems and significant challenges, such as the competitive hydrogen evolution reaction and its low current density, as well as low selectivity, low stability, and ultra-low conversion rates for multi-carbon products, all of which greatly limit their future practical applications.

[0004] Therefore, designing an electrocatalyst and carbon dioxide electroreduction reaction system with high selectivity, catalytic activity and stability is of great significance for maintaining the carbon cycle of the ecosystem and solving the energy shortage problem. Summary of the Invention

[0005] The purpose of this invention is to provide a supported catalyst and its preparation method and application, a gas diffusion electrode and its preparation method, and a method for carbon dioxide reduction. The supported catalyst, copper clusters / copper-BTC, acts as an electrocatalyst to activate carbon dioxide gas and lower the reaction energy barrier of key intermediates, exhibiting high activity and selectivity in the electrocatalytic reduction of carbon dioxide to multi-carbon products. Furthermore, the preparation method of this supported catalyst is environmentally friendly, easy to control, and has the advantages of short reaction cycle, high yield, low cost, stable product quality, and uniform morphology. This supported catalyst can also be used to prepare a gas diffusion electrode, which can be used for the reduction reaction of carbon dioxide, providing a new approach for the electrochemical reduction system of carbon dioxide.

[0006] To achieve the above objectives, the first aspect of the present invention provides a supported catalyst, wherein the support of the supported catalyst comprises copper-BTC and the active component comprises copper clusters.

[0007] A second aspect of the present invention provides a method for preparing the supported catalyst as described above, the method comprising: 1) A copper cluster solution is obtained by first mixing the copper source, reducing agent, and solvent; 2) The copper cluster solution is mixed with copper salt solution and trimesic acid solution for the second time, the solvent is removed, the mixture is washed, and then vacuum dried.

[0008] The third aspect of this invention provides an application of the supported catalyst described in the first aspect in the preparation of a gas diffusion electrode.

[0009] A fourth aspect of the present invention provides a gas diffusion electrode comprising the supported catalyst described in the first aspect.

[0010] A fifth aspect of the present invention provides a method for preparing the above-mentioned gas diffusion electrode, the method comprising: 1) Disperse the supported catalyst in a dispersant and add a binder to obtain a mixture; 2) Load the mixture described in step 1) onto carbon paper to obtain the gas diffusion electrode.

[0011] A sixth aspect of the present invention provides a method for catalytic electrochemical reduction of carbon dioxide to multi-carbon products, the method comprising: assembling a gas diffusion electrode in a flow electrolytic cell using a three-electrode system, and introducing carbon dioxide gas and circulating electrolyte to carry out a carbon dioxide electroreduction reaction; The gas diffusion electrode is the gas diffusion electrode described in the fourth aspect of this invention.

[0012] In the above technical solution, the present invention first prepares a copper cluster solution by a simple solvent method, and then prepares two solutions required for the synthesis of copper-BTC. The copper clusters are then coated by the copper-BTC formation process to obtain a supported catalyst copper cluster / copper-BTC.

[0013] This invention, for the first time, proposes using copper clusters / copper-BTC materials as electrocatalysts for the reduction of carbon dioxide to multi-carbon products, providing a novel approach for copper clusters / copper-BTC materials and the electrochemical reduction system of carbon dioxide. The copper clusters / copper-BTC materials exhibit high catalytic efficiency in the carbon dioxide reduction process, along with very low competing hydrogen production (Faraday efficiency of approximately 8%) and high multi-carbon product conversion rates (Faraday efficiency approaching 85%). Furthermore, the copper clusters / copper-BTC materials are uniformly loaded on carbon paper, allowing carbon dioxide gas to pass through the porous layer of the carbon paper to reach the catalyst surface and undergo a reduction reaction with the electrolyte, enabling a gas-liquid-solid three-phase reaction. This allows the highly efficient electrocatalytic carbon dioxide reduction method provided by this invention to be applied in complex electrochemical environments, with low cost and high selectivity, exhibiting significant competitive advantages.

[0014] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0015] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a transmission electron microscope image of the supported catalyst copper cluster / copper-BTC material B1 prepared in Example 1, magnified 30,000 times. Figure 2 This is a transmission electron microscope (TEM) image of the supported catalyst copper cluster / copper-BTC material B5 prepared in Example 5, magnified 50,000 times. Figure 3 This is a transmission electron microscope image of copper-BTC material D1 prepared in Comparative Example 1, magnified 10,000 times. Figure 4 The images show the XRD patterns of the supported catalyst copper cluster / copper-BTC material B1 prepared in Example 1 and the copper-BTC material D1 prepared in Comparative Example 1 at 2θ angles of 5-80°. Figure 5 This is a graph showing the relationship between the Faraday efficiency and current density of various products obtained from the B1 test of the supported catalyst copper cluster / copper-BTC material B1 prepared in Example 1. Figure 6This is a graph showing the relationship between partial Radie efficiency and partial current density and current density obtained from the B1 test of the supported catalyst copper cluster / copper-BTC material B1 prepared in Example 1; Figure 7 This is a graph showing the relationship between the Faraday efficiency and current density of various products obtained from the test of copper-BTC material D1 prepared in Comparative Example 1. Figure 8 This is a graph showing the relationship between partial Radius efficiency and partial current density and current density obtained from the D1 test of the copper-BTC material prepared in Comparative Example 1. Figure 9 This is a transmission electron microscope (TEM) image of the supported catalyst copper cluster / copper-BTC material B1 prepared in Example 1, magnified 40,000 times after a carbon dioxide reduction test. Detailed Implementation

[0016] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0017] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] The first aspect of the present invention provides a supported catalyst, wherein the support of the supported catalyst comprises copper-BTC and the active component comprises copper clusters.

[0019] The gas diffusion electrode prepared by the supported catalyst copper cluster / copper-BTC of the present invention provides a great promoting effect on the deep reduction of carbon dioxide, and exhibits high conversion efficiency and selectivity.

[0020] In a preferred embodiment of the present invention, the active component in the catalyst is coated with a support, forming a core-shell structure.

[0021] In a preferred embodiment of the present invention, the size of the copper cluster is 3-6 nm.

[0022] In a preferred embodiment of the present invention, the copper-BTC has an octahedral structure.

[0023] In a preferred embodiment of the present invention, the copper-BTC has a size of 100-250 nm.

[0024] In a preferred embodiment of the present invention, the size of the copper-BTC is 100-200nm.

[0025] In a preferred embodiment of the present invention, in the supported catalyst, the molar ratio of copper clusters to copper-BTC is 1:5-15, based on copper atoms.

[0026] A second aspect of the present invention provides a method for preparing the supported catalyst as described above, the method comprising: 1) A copper cluster solution is obtained by first mixing the copper source, reducing agent, and solvent; 2) The copper cluster solution is mixed with copper salt solution and trimesic acid solution for the second time, the solvent is removed, the mixture is washed, and then vacuum dried.

[0027] This invention provides a simple preparation method for obtaining supported catalyst copper clusters / copper-BTC. This preparation method is environmentally friendly, easy to control, has a short reaction cycle, high yield, low cost, and produces products with stable quality and uniform morphology.

[0028] In a preferred embodiment of the present invention, in step 1), the type of copper salt can be selected from a wide range. However, in order to make the obtained copper cluster solution have better catalytic activity, in step 1), the copper source is at least one of copper nitrate, acetate, sulfate and halide salt.

[0029] In a preferred embodiment of the present invention, in step 1), the type of copper salt can be selected from a wide range, but in order to make the obtained copper cluster solution have better catalytic activity, the copper salt is selected from at least one of copper nitrate, copper acetate, copper sulfate, and copper chloride.

[0030] In a preferred embodiment of the present invention, in step 1), the type of copper salt can be selected from a wide range, but in order to make the obtained copper cluster solution have better catalytic activity, the copper salt is copper nitrate.

[0031] In a preferred embodiment of the present invention, in step 1), the type of reducing agent can be selected from a wide range, but in order to make the formed copper cluster solution have better properties, the reducing agent is selected from at least one of ascorbic acid, sodium borohydride and potassium borohydride.

[0032] In a preferred embodiment of the present invention, in step 1), the type of solvent can be selected from a wide range, but in order to allow the copper salt and the reducing agent to react more fully and without producing other byproducts, the solvent is at least one of ultrapure water, ethanol, methanol and N,N-dimethylamide.

[0033] In a preferred embodiment of the present invention, in step 1), the mass ratio of the copper salt, reducing agent and solvent can be selected within a wide range. However, in order to make the formed copper cluster solution have better properties, the mass ratio of the copper source, reducing agent and solvent (calculated as copper element) is 1:5-10:0.5-2.

[0034] In a preferred embodiment of the present invention, in step 1), the conditions for the first mixing can be selected within a wide range, but in order to allow the copper salt and reducing agent to react more fully, the conditions for the first mixing include: a time of 0.5-1.5 h and a temperature of 15-30 °C.

[0035] In a preferred embodiment of the present invention, in step 1), the first mixing method can be a conventional choice in the art, such as stirring. According to the present invention, the stirring conditions include a rotation speed of 500-1000 rpm.

[0036] In a preferred embodiment of the present invention, in step 2), the solvent of the copper salt solution can be selected from a wide range. However, in order to ensure that the reactants can react smoothly and to avoid the occurrence of side reactions, in step 2), the solvent of the copper salt solution is selected from at least one of water, ethanol, methanol and N,N-dimethylamide.

[0037] In a preferred embodiment of the present invention, in step 2), the type of copper salt in the copper salt solution can be selected from a wide range. However, in order to ensure that the reactants can react smoothly and to avoid the occurrence of side reactions, in step 2), the copper salt in the copper salt solution is selected from at least one of copper nitrate, copper acetate, copper sulfate, and copper chloride.

[0038] In a preferred embodiment of the present invention, in step 2), the type of copper salt in the copper salt solution can be selected from a wide range. However, in order to ensure that the reactants can react smoothly and to avoid the occurrence of side reactions, in step 2), the copper salt in the copper salt solution is copper nitrate.

[0039] In a preferred embodiment of the present invention, the mass ratio of copper salt to solvent in the copper salt solution can be selected within a wide range. However, in order to obtain a supported catalyst with better catalytic performance, the mass ratio of copper salt to solvent in the copper salt solution is 1:25-55.

[0040] In a preferred embodiment of the present invention, the solvent of the pyromellitic acid solution can be selected from a wide range of types. However, in order to ensure that the reactants can react smoothly and to avoid the occurrence of side reactions, the solvent of the pyromellitic acid solution is selected from at least one of water, ethanol, methanol and N,N-dimethylamide.

[0041] In a preferred embodiment of the present invention, the mass ratio of trimellitic acid to solvent in the trimellitic acid solution can be selected within a wide range. However, in order to obtain a supported catalyst with better catalytic performance, the mass ratio of trimellitic acid to solvent in the trimellitic acid solution is 1:15-60.

[0042] In a preferred embodiment of the present invention, the dissolution methods of the copper salt and trimellitic acid can be selected within a wide range. However, in order to make the copper salt and trimellitic acid more uniformly dispersed, the copper salt is ultrasonically dissolved in ultrapure water and the trimellitic acid is ultrasonically dissolved in anhydrous ethanol.

[0043] In a preferred embodiment of the present invention, in step 2), the volume ratio of the copper cluster solution, copper salt solution and trimesic acid solution can be selected within a wide range. However, in order to obtain a supported catalyst with better catalytic performance, in step 2), the volume ratio of the copper cluster solution, copper salt solution and trimesic acid solution is 15-30:15-25:15-25.

[0044] In a preferred embodiment of the present invention, in step 2), the conditions for the second mixing can be selected within a wide range. However, in order to ensure that the copper cluster solution, copper salt solution and trimesic acid solution react fully and to quickly prepare the supported catalyst, the conditions for the second mixing in step 2) include: a time of 0.5-1.0 h and a temperature of 15-30 °C.

[0045] In this invention, the second mixing method can be a conventional choice in the art, such as stirring. According to this invention, the stirring conditions include a rotation speed of 500-1000 rpm.

[0046] In a preferred embodiment of the present invention, the second mixing method can be selected within a wide range. However, in order to enable the copper clusters of the supported catalyst to be better coated by copper-BTC, the second mixing method is to first add a copper cluster solution, then add a copper salt solution, and finally add a trimesic acid solution.

[0047] In a preferred embodiment of the present invention, the solvent removal method can be selected from a wide range, but in order to ensure the smooth progress of subsequent steps, the solvent removal method includes vacuum filtration.

[0048] In a preferred embodiment of the present invention, the filtration method can be selected within a wide range, but in order to ensure the smooth progress of subsequent steps, the filter should be left to stand for 2-15 minutes before filtration.

[0049] In a preferred embodiment of the present invention, the washing conditions can be selected within a wide range. However, in order to wash the reactants clean and reduce losses, the washing is performed by centrifugation, filtration and washing 3-5 times with ultrapure water and ethanol, respectively.

[0050] In a preferred embodiment of the present invention, the conditions for vacuum drying can be selected within a wide range, but in order to protect the structure and properties of the reactants from change, the temperature for vacuum drying is 50-90°C and the time is 8-20 hours.

[0051] A third aspect of the present invention provides the application of the supported catalyst as described in the first aspect in the preparation of a gas diffusion electrode.

[0052] A fourth aspect of the present invention provides a gas diffusion electrode comprising the supported catalyst described in the first aspect.

[0053] A fifth aspect of the present invention provides a method for preparing the gas diffusion electrode described in the fourth aspect, the method comprising: 1) Disperse the supported catalyst in a dispersant and add a binder to obtain a mixture; 2) Load the mixture onto carbon paper to obtain the gas diffusion electrode.

[0054] In a preferred embodiment of the present invention, the type of dispersant can be selected from a wide range, but in order to make the supported catalyst more uniformly dispersed and the electrode with better conductivity, the dispersant is a mixed solution of water and ethanol.

[0055] In a preferred embodiment of the present invention, the proportion of the dispersant can be selected within a wide range. However, in order to make the supported catalyst more uniformly dispersed and to make the gas diffusion electrode with better conductivity, the volume ratio of water to ethanol in the dispersant is 1:1-10.

[0056] In a preferred embodiment of the present invention, the type of binder can be selected from a wide range, but in order to ensure the conductivity of the obtained gas diffusion electrode, the binder is selected from at least one of perfluorinated resin solution, polyvinyl alcohol and polyvinylidene fluoride.

[0057] In a preferred embodiment of the present invention, the ratio of the supported catalyst, dispersant and binder can be selected within a wide range. However, in order to improve the conductivity of the gas diffusion electrode, the ratio of the supported catalyst, dispersant and binder is 2-15 mg: 0.45-1.9 mL: 10-100 μL.

[0058] The sixth aspect of the present invention provides a method for catalytic electrochemical reduction of carbon dioxide to multi-carbon products, the method comprising: assembling a gas diffusion electrode in a flow electrolytic cell using a three-electrode system, and introducing carbon dioxide gas and circulating electrolyte to carry out a carbon dioxide electroreduction reaction; The gas diffusion electrode is the gas diffusion electrode described in the fourth aspect.

[0059] This invention utilizes supported catalyst copper clusters / copper-BTC as an electrocatalyst to promote the electrochemical reduction of carbon dioxide. In a fluid dynamic electrolytic cell, the gas diffusion electrode prepared by copper clusters / copper-BTC material provides a great promoting effect on the deep reduction of carbon dioxide, exhibiting high conversion efficiency and selectivity.

[0060] In a preferred embodiment of the present invention, the type of electrolyte can be selected from a wide range, but in order to ensure electron transport efficiency, the electrolyte is selected from at least one of potassium hydroxide, potassium bicarbonate, potassium sulfate, and potassium chloride.

[0061] The present invention will be described in detail below through examples, but the scope of protection of the present invention is not limited thereto. In the following examples, the drugs and pharmaceuticals are all conventional commercially available products.

[0062] Example 1 (1) Dissolve 50 mg of copper nitrate completely in 15 mL of ultrapure water at 25 °C, then add 400 mg of ascorbic acid while stirring evenly, mix evenly and stir for 1.5 h to obtain copper cluster solution; (2) Dissolve 0.6g of copper nitrate in 22mL of ultrapure water and 0.6g of trimesic acid in 20mL of anhydrous ethanol, and then sonicate each solution to obtain a homogeneous solution. Then, the copper cluster solution, copper nitrate solution and trimesic acid solution were mixed sequentially and stirred at 25°C and 1000 rpm for 0.5 h. (3) After the stirring reaction is completed, let it stand for 5 minutes, filter the resulting mixed solution, and wash the solid material obtained by vacuum filtration with ultrapure water and anhydrous ethanol 4 times each, and then put it into a vacuum drying oven and dry it at 60°C for 18 hours to obtain the supported catalyst copper cluster / copper-BTC material, denoted as B1.

[0063] Example 2 (1) Dissolve 50 mg of copper nitrate completely in 15 mL of ultrapure water at 15 °C, then add 200 mg of ascorbic acid while stirring evenly, mix evenly and stir for 1.5 h to obtain copper cluster solution; (2) Dissolve 0.4g of copper nitrate in 20mL of ultrapure water and 0.4g of trimesic acid in 20mL of anhydrous ethanol, and then sonicate each solution to obtain a homogeneous solution. Then, the copper cluster solution, copper nitrate solution and trimesic acid solution were mixed sequentially and stirred at 15°C and 800 rpm for 1 hour. (3) After the stirring reaction is completed, let it stand for 2 minutes, filter the resulting mixed solution, and wash the solid material obtained by vacuum filtration with ultrapure water and anhydrous ethanol 4 times each, and then put it into a vacuum drying oven and dry it at 50°C for 20 hours to obtain the supported catalyst copper cluster / copper-BTC material, denoted as B2.

[0064] Example 3 (1) Dissolve 70 mg of copper nitrate completely in 20 mL of ultrapure water at 30 °C, then add 400 mg of ascorbic acid under uniform stirring, mix well and stir for 1 h to obtain copper cluster solution; (2) Dissolve 0.5g of copper nitrate in 20mL of ultrapure water and 0.4g of pyromellitic acid in 15mL of anhydrous ethanol, and then sonicate each solution to obtain a homogeneous solution. Then, the copper cluster solution, copper nitrate solution and trimesic acid solution were mixed sequentially and stirred at 30°C and 800 rpm for 1 hour. (3) After the stirring reaction is completed, let it stand for 7 minutes, filter the resulting mixed solution, and wash the solid material obtained by vacuum filtration with ultrapure water and anhydrous ethanol 4 times each, and then put it into a vacuum drying oven and dry it at 70°C for 14 hours to obtain the supported catalyst copper cluster / copper-BTC material, denoted as B3.

[0065] Example 4 (1) Dissolve 70 mg of copper nitrate completely in 30 mL of ultrapure water at 25 °C, then add 450 mg of ascorbic acid under uniform stirring, mix well and stir for 1.5 h to obtain copper cluster solution; (2) Dissolve 0.5g of copper nitrate in 15mL of ultrapure water and 0.8g of pyromellitic acid in 25mL of anhydrous ethanol, and then sonicate each solution to obtain a homogeneous solution. Then, the copper cluster solution, copper nitrate solution and trimesic acid solution were mixed sequentially and stirred at 25°C and 800 rpm for 1 hour. (3) After the stirring reaction is completed, let it stand for 15 minutes, filter the resulting mixed solution, and wash the solid material obtained by vacuum filtration with ultrapure water and anhydrous ethanol 5 times each, and then put it into a vacuum drying oven and dry it at 90°C for 8 hours to obtain the supported catalyst copper cluster / copper-BTC material, denoted as B4.

[0066] Example 5 (1) Dissolve 50 mg of copper acetate completely in 15 mL of ultrapure water at 25 °C, then add 400 mg of ascorbic acid while stirring evenly, mix evenly and stir for 1.5 h to obtain copper cluster solution; (2) Dissolve 0.6g of copper acetate in 22mL of ultrapure water and 0.6g of pyromellitic acid in 20mL of anhydrous ethanol, and then sonicate each solution to obtain a homogeneous solution. Then, the copper cluster solution, copper acetate solution, and trimesic acid solution were mixed sequentially and stirred at 25°C and 1000 rpm for 0.5 h. (3) After the stirring reaction is completed, let it stand for 5 minutes, filter the resulting mixed solution, and wash the solid material obtained by vacuum filtration with ultrapure water and anhydrous ethanol 4 times each, and then put it into a vacuum drying oven and dry it at 60°C for 18 hours to obtain the supported catalyst copper cluster / copper-BTC material, denoted as B5.

[0067] Example 6 (1) Dissolve 50 mg of copper sulfate completely in 15 mL of ultrapure water at 25 °C, then add 400 mg of ascorbic acid while stirring evenly, mix evenly and stir for 1.5 h to obtain copper cluster solution; (2) Dissolve 0.6g of copper sulfate in 22mL of ultrapure water and 0.6g of trimesic acid in 20mL of anhydrous ethanol, and then sonicate each solution to obtain a homogeneous solution. Then, the copper cluster solution, copper sulfate solution, and trimesic acid solution were mixed sequentially and stirred at 25°C and 800 rpm for 0.5 h. (3) After the stirring reaction is completed, let it stand for 5 minutes, filter the resulting mixed solution, and wash the solid material obtained by vacuum filtration with ultrapure water and anhydrous ethanol 4 times each, and then put it into a vacuum drying oven and dry it at 60°C for 18 hours to obtain the supported catalyst copper cluster / copper-BTC material, denoted as B6.

[0068] Comparative Example 1 (1) At 25℃, 0.6g of copper nitrate was dissolved in 22mL of ultrapure water and 0.6g of trimesic acid was dissolved in 20mL of anhydrous ethanol. The solutions were then sonicated to obtain homogeneous solutions. Then, the copper nitrate solution and the trimellitic acid solution were mixed sequentially and stirred at 25°C and 1000 rpm for 0.5 h. (2) After the stirring reaction is completed, let it stand for 5 minutes, filter the resulting mixed solution, and wash the solid material obtained by vacuum filtration with ultrapure water and anhydrous ethanol 4 times each, and then put it into a vacuum drying oven and dry it at 60°C for 18 hours to obtain copper-BTC material, denoted as D1.

[0069] Comparative Example 2 (1) At 25℃, 0.6g of copper acetate was dissolved in 22mL of ultrapure water and 0.6g of pyromellitic acid was dissolved in 20mL of anhydrous ethanol, and each was sonicated to obtain a homogeneous solution. Then, the copper acetate solution and the trimesic acid solution were mixed sequentially and stirred at 25°C and 1000 rpm for 0.5 h. (2) After the stirring reaction is completed, let it stand for 5 minutes, filter the resulting mixed solution, and wash the solid material obtained by vacuum filtration with ultrapure water and anhydrous ethanol 4 times each, and then put it into a vacuum drying oven and dry it at 60°C for 18 hours to obtain copper-BTC material, denoted as D2.

[0070] Detection Example 1 The materials prepared in Examples 1, 5, and Comparative Example 1 were examined by transmission electron microscopy. Specific results are shown in […]. Figure 1-3 .

[0071] Depend on Figure 1 As can be seen from the TEM image, the supported catalyst copper cluster / copper-BTC material B1 prepared in Example 1 is composed of copper-BTC with a size of 100-200 nm covering copper clusters of 3-6 nm. The octahedral structure of copper-BTC provides sufficient space for the tiny copper clusters and prevents the copper clusters from agglomerating.

[0072] Depend on Figure 2 As can be seen from the TEM image, the supported catalyst copper cluster / copper-BTC material B5 prepared in Example 5 consists of copper clusters coated with larger octahedral copper-BTC, with an overall size of approximately 150-250 nm.

[0073] Depend on Figure 3 The TEM image shows that the copper-BTC material D1 prepared in Comparative Example 1 is composed of octahedrons with a size of 250-400 nm, and the presence of copper clusters is not clearly observed.

[0074] Detection Example 2 The materials prepared in Example 1 and Comparative Example 1 were subjected to XRD analysis. Specific results are shown in [Figure 1]. Figure 4 .

[0075] Depend on Figure 4 The XRD patterns reveal the material composition of the supported catalyst copper cluster / copper-BTC material B1 prepared in Example 1 and the copper-BTC material D1 prepared in Comparative Example 1. Standard card analysis shows that the supported catalyst copper cluster / copper-BTC material B1 prepared in Example 1 is mainly composed of copper-BTC and copper clusters, while the copper-BTC material D1 prepared in Comparative Example 1 contains only copper-BTC.

[0076] Application Example 1 1. Preparation of diffusion electrode: Add 5 mg of material to 2 mL of a mixture of water and ethanol (volume ratio 2:1), and add 50 µL of perfluorinated resin solution. After uniform dispersion, coat the resulting ink onto carbon paper and let it dry for later use.

[0077] 2. Assembly of flowing electrolytic cells: The anode and cathode electrolysis chambers of the flowing electrolyzer are separated by anion exchange membranes and connected to the leachate pipes of the anode and cathode electrolysis chambers according to the "bottom in, top out" principle. Carbon dioxide gas is also connected from one side of the gas chamber according to the same "bottom in, top out" principle. This ultimately forms a flowing electrolyzer for three-phase reactions, with electrolyte circulation and a constant gas flow rate.

[0078] 3. Carbon dioxide electroreduction test: The carbon dioxide electroreduction test employs a three-electrode system: a working electrode, a reference electrode, and a counter electrode. The electrochemical process is continuously carried out at a constant negative potential, causing the carbon dioxide gas to undergo an electrochemical reduction reaction in the cathode chamber.

[0079] After the reaction stabilized, the products were collected and analyzed. The gaseous and liquid phase products were analyzed by gas chromatography and proton nuclear magnetic resonance spectroscopy, respectively. The test results are as follows: Figure 5 As shown.

[0080] Depend on Figure 5 It can be seen that the supported catalyst copper cluster / copper-BTC material B1 prepared in Example 1 achieves a current density of 300 mA·cm⁻¹ in a neutral electrolyte. -2 At that time, the yield of hydrogen in the competing reaction was extremely low, with a Faraday efficiency (FE) of only 8%, while carbon dioxide exhibited extremely high selectivity, with an FE of approximately 92%. Among these, the multi-carbon products (i.e., C in the figure) yielded very little. 2+ FE > 80%.

[0081] Depend on Figure 6 It can be seen that the supported catalyst copper cluster / copper-BTC material B1 prepared in Example 1 exhibits excellent selectivity in the partial FE and partial current density of the electrolytic products during electroreduction, showing that carbon dioxide electroreduction to multi-carbon products is clearly observed.

[0082] Depend on Figure 7 It can be seen that when the copper-BTC material D1 prepared in Comparative Example 1 was tested under the same conditions as the supported catalyst copper cluster / copper-BTC material B1 prepared in Example 1, the results showed that the yield of competing hydrogen was increased and the FE of multi-carbon products decreased significantly, to less than 70%.

[0083] Depend on Figure 8 It can be seen that the copper-BTC material D1 prepared in Comparative Example 1 exhibits lower selectivity for partial FE and partial current density of electrolytic products and multi-carbon products during electroreduction compared to the supported catalyst copper cluster / copper-BTC material B1 prepared in Example 1.

[0084] Detection Example 4 Material structural stability assessment: The material prepared in Example 1 underwent electrochemical testing, followed by structural stability studies. Specific results are shown below. Figure 9 .

[0085] pass Figure 9 As can be seen from the TEM images, after the supported catalyst copper cluster / copper-BTC material B1 prepared in Example 1 was subjected to a constant potential test with a certain negative value in the electrolyte, the microstructure of the material did not collapse, and the copper clusters inside the octahedral copper-BTC did not agglomerate, indicating that the supported catalyst copper cluster / copper-BTC material prepared in this invention has good structural stability.

[0086] The supported catalysts B2-B6 prepared in this invention were subjected to the same tests as described above, and the results of B2-B6 were basically consistent with those of B1. The material D2 prepared in Comparative Example 2 of the present invention was also subjected to the above tests, and the results were consistent with those of D1.

[0087] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0088] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0089] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A supported catalyst, characterized in that, The supported catalyst comprises copper-BTC, and the active component comprises copper clusters; The active component in the catalyst is encapsulated by a support, forming a core-shell structure. The size of the copper clusters is 3-6 nm; The copper-BTC has an octahedral structure; The copper-BTC has a size of 100-250nm; In the supported catalyst, the molar ratio of copper clusters to copper-BTC is 1:5-15, based on copper atoms.

2. The supported catalyst according to claim 1, characterized in that, The copper-BTC has a size of 100-200nm.

3. A method for preparing a supported catalyst as described in claim 1 or 2, characterized in that, The preparation method includes: 1) A copper cluster solution is obtained by first mixing the copper source, reducing agent, and solvent; 2) The copper cluster solution is mixed with copper salt solution and trimesic acid solution for the second time, the solvent is removed, the mixture is washed, and then vacuum dried; In step 1), the copper source is selected from at least one of copper nitrates, acetates, sulfates, and halides; In step 1), the reducing agent is selected from at least one of ascorbic acid, sodium borohydride, and potassium borohydride; In step 1), the solvent is at least one of ultrapure water, ethanol, methanol, and N,N-dimethylamide; In step 1), the conditions for the first mixing include: a time of 0.5-1.5 h and a temperature of 15-30 °C; In step 2), the solvent in the copper salt solution is at least one of water, ethanol, methanol, and N,N-dimethylamide; In step 2), the copper salt in the copper salt solution is selected from at least one of copper nitrate, copper acetate, copper sulfate, and copper chloride; In step 2), the mass ratio of copper salt to solvent in the copper salt solution is 1:25-55; In step 2), the solvent in the pyromellitic acid solution is at least one of water, ethanol, methanol, and N,N-dimethylamide; In step 2), the mass ratio of trimesic acid to solvent in the trimesic acid solution is 1:15-60; In step 2), the volume ratio of the copper cluster solution, copper salt solution, and trimesic acid solution is 15-30:15-25:15-25; In step 2), the conditions for the second mixing include: a time of 0.5-1.0 h and a temperature of 15-30 °C; In step 2), the second mixing method is to first add a copper cluster solution, then add a copper salt solution, and finally add a trimesic acid solution; In step 2), the solvent removal method includes vacuum filtration.

4. The preparation method according to claim 3, wherein, In step 1), the copper source is selected from at least one of copper nitrate, copper acetate, copper sulfate, and copper chloride.

5. The preparation method according to claim 4, wherein, In step 1), the copper source is copper nitrate.

6. The preparation method according to claim 3, wherein, In step 2), the copper salt in the copper salt solution is copper nitrate.

7. The preparation method according to claim 3, wherein, The filtration process also includes allowing the sample to stand for 2-15 minutes before filtration. In step 2), the washing conditions include: filtration with ultrapure water and ethanol, and washing 3-5 times respectively; In step 2), the vacuum drying conditions include: a drying temperature of 50-90℃ and a drying time of 8-20h.

8. The application of a supported catalyst as described in claim 1 or 2 in the preparation of a gas diffusion electrode.

9. A gas diffusion electrode, characterized in that, The gas diffusion electrode comprises the supported catalyst as described in claim 1 or 2.

10. A method for preparing the gas diffusion electrode according to claim 9, characterized in that, The method includes: 1) Disperse the supported catalyst in a dispersant and add a binder to obtain a mixture; 2) Loading the mixture onto carbon paper yields the gas diffusion electrode; The dispersant is a mixed solution of water and ethanol, wherein the volume ratio of water to ethanol in the mixed solution is 1:1-10; The adhesive is selected from at least one of perfluorinated resin solution, polyvinyl alcohol, and polyvinylidene fluoride; The ratio of the supported catalyst, dispersant, and binder is 2-15 mg: 0.45-1.9 mL: 10-100 μL.

11. A method for catalytic electrochemical reduction of carbon dioxide to multi-carbon products, characterized in that, The method includes: assembling a gas diffusion electrode in a flowing electrolytic cell using a three-electrode system, and introducing carbon dioxide gas and circulating electrolyte to carry out a carbon dioxide electroreduction reaction; Wherein, the gas diffusion electrode is the gas diffusion electrode according to claim 9; The electrolyte is selected from at least one of potassium hydroxide, potassium bicarbonate, potassium sulfate, and potassium chloride.

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