A copper oxide nanosheet catalyst supported on metal single-atom coordination compounds, its preparation method and application

Abstract

This invention provides a copper oxide nanosheet catalyst supported on metal single-atom coordination compounds, its preparation method, and its applications, belonging to the field of materials science and technology. This invention combines copper oxide nanosheets with molecules containing metal single atoms through molecular adsorption, thereby modifying the surface of the copper oxide nanosheets and forming a tandem structure of nitrogen-coordinated active sites and defective copper oxide. Compared with copper oxide nanosheet catalysts without added metal single-atom molecules, the adsorption of these molecules increases the surface roughness of the catalyst, exposing a large number of active sites on the surface, resulting in higher conductivity. At low overpotentials, the tandem synergy between the nitrogen-coordinated active sites and the defective structure effectively attracts and adsorbs *CO intermediates to the defective sites, facilitating the stable adsorption and aggregation of *CO intermediates on the copper oxide surface, promoting carbon-carbon coupling, and encouraging greater conversion of CO2 to C2H4.

Description

Technical Field

[0001] This invention relates to the field of materials science and technology, and in particular to a copper oxide nanosheet catalyst supported on metal single-atom coordination compounds, its preparation method, and its application. Background Technology

[0002] Rapid economic development has exacerbated the depletion of fossil resources, generating large amounts of carbon dioxide (CO2) and posing a serious threat to global warming. Therefore, using renewable and clean energy to reduce CO2 and utilize it as a resource is crucial for promoting sustainable human development. Electrochemical methods for CO2 reduction offer advantages such as environmental friendliness, high efficiency, and relatively low investment, and can convert CO2 into industrial resources such as ethylene.

[0003] Ethylene (C2H4) has long been an indispensable cornerstone of the chemical industry. In traditional industrial production, ethylene is typically produced by the steam cracking of petroleum under harsh high-temperature conditions. In recent years, the electrochemical catalytic reduction of CO2 to ethylene has attracted increasing attention, offering a mild and green synthetic route for ethylene production. Meanwhile, copper-based nanomaterials have found applications in many fields, particularly in CO2RR electrocatalysis.

[0004] Single-atom catalysts combine the homogeneous and singular active centers of homogeneous catalysts with the structural stability and ease of separation of heterogeneous catalysts, thus linking heterogeneous and homogeneous catalysis. Single-atom catalysts have been extensively studied in the field of electrocatalysis. They possess high catalytic activity and stability, but suffer from low selectivity for C2 products. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a copper oxide nanosheet catalyst supported on metal single-atom coordination sites, its preparation method, and its application. This invention utilizes the synergistic effect of the nitrogen coordination active sites on the metal single atom and the defects in copper oxide to stabilize the adsorption and aggregation of the intermediate *CO on the copper oxide surface, promote carbon-carbon coupling, enhance the catalyst's activity in carbon dioxide electroreduction, and improve selectivity for C2 products.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a copper oxide nanosheet catalyst supported on metal single-atom coordination compounds, comprising copper oxide nanosheets and molecules containing metal single atoms supported on the surface of the copper oxide nanosheets. The metal single-atom-containing molecules include one or more of the following: iron phthalocyanine, nickel phthalocyanine, cobalt phthalocyanine, copper phthalocyanine, zinc phthalocyanine, titanium phthalocyanine, manganese phthalocyanine, lead phthalocyanine, tin phthalocyanine, platinum phthalocyanine, vanadium phthalocyanine, magnesium phthalocyanine, indium phthalocyanine, bismuth phthalocyanine, aluminum phthalocyanine chloride, gallium phthalocyanine chloride, titanium phthalocyanine, vanadium phthalocyanine, tin dichlorophthalocyanine, cobalt phthalocyanine sulfonated, and their phthalocyanine metal derivatives.

[0008] Preferably, the copper oxide nanosheets are two-dimensional planar structures with an average thickness of 10–20 nm.

[0009] Preferably, the molecule containing a single metal atom includes iron phthalocyanine and cobalt phthalocyanine.

[0010] Preferably, the mass ratio of iron phthalocyanine to cobalt phthalocyanine is 1:1.

[0011] This invention also provides a method for preparing the copper oxide nanosheet catalyst supported on metal single-atom coordination structures as described above, comprising the following steps:

[0012] A precursor is obtained by mixing a copper salt solution, a strong alkaline solution, and a molecule containing a single metal atom.

[0013] The precursor was subjected to hydrothermal treatment followed by solid-liquid separation, washing, and freeze-drying to obtain the copper oxide nanosheet catalyst supported on metal single-atom coordination compounds.

[0014] Preferably, the molecule containing the metal single atom reacts with Cu in the copper salt solution. 2+ The molar ratio is 1:10 to 1:100000.

[0015] Preferably, the copper salt solution contains Cu 2+ With OH in strong alkaline solutions - The molar ratio is 1:2 to 1:20.

[0016] Preferably, the hydrothermal treatment is performed at a temperature of 60–120°C for a duration of 2–24 hours.

[0017] Preferably, the hydrothermal treatment is performed at a temperature of 90–100°C for 4–8 hours.

[0018] The present invention also provides the application of the copper oxide nanosheet catalyst supported on metal single-atom coordination compounds as described in the above technical solutions or the copper oxide nanosheet catalyst supported on metal single-atom coordination compounds prepared by the preparation method described in the above technical solutions in the field of carbon dioxide electroreduction catalysis.

[0019] This invention provides a copper oxide nanosheet catalyst supported on metal single-atom coordination compounds, comprising copper oxide nanosheets and molecules containing metal single atoms supported on the surface of the copper oxide nanosheets. The metal single-atom-containing molecules include one or more of the following: iron phthalocyanine, nickel phthalocyanine, cobalt phthalocyanine, copper phthalocyanine, zinc phthalocyanine, titanium phthalocyanine, manganese phthalocyanine, lead phthalocyanine, tin phthalocyanine, platinum phthalocyanine, vanadium phthalocyanine, magnesium phthalocyanine, indium phthalocyanine, bismuth phthalocyanine, aluminum phthalocyanine chloride, gallium phthalocyanine chloride, titanium phthalocyanine, vanadium phthalocyanine, tin dichlorophthalocyanine, cobalt phthalocyanine sulfonated, and their phthalocyanine metal derivatives.

[0020] This invention combines copper oxide nanosheets with molecules containing single metal atoms through molecular adsorption, thereby modifying the surface of the copper oxide nanosheets and forming a tandem structure of nitrogen-coordinated active sites and defective copper oxide. Compared with copper oxide nanosheet catalysts without the addition of molecules containing single metal atoms, the adsorption of molecules containing single metal atoms increases the surface roughness of the catalyst, exposing a large number of active sites on the surface, resulting in higher conductivity. At low overpotentials, the tandem synergy between the nitrogen-coordinated active sites and the defective structure can effectively attract and adsorb *CO intermediates to the defective sites, which is beneficial for stabilizing the adsorption and aggregation of intermediate *CO on the copper oxide surface, promoting carbon-carbon coupling, and facilitating the conversion of more CO2 into C2H4. This gives the catalyst excellent catalytic activity and selectivity for the electroreduction of carbon dioxide.

[0021] This invention also provides a method for preparing the copper oxide nanosheet catalyst supported on metal single-atom coordination compounds as described above. The method forms a structure in series between the nitrogen coordination active sites of metal single atoms and the defective copper oxide through a hydrothermal process. This method is simple, fast, and suitable for industrial applications. Attached Figure Description

[0022] Figure 1 These are scanning electron microscope (SEM) images of the catalyst obtained in Example 1 at different magnifications;

[0023] Figure 2 The elemental analysis (EDX) diagram of the catalyst obtained in Example 1;

[0024] Figure 3 The image shows the X-ray diffraction (XRD) pattern of the catalyst obtained in Example 1.

[0025] Figure 4 The graph shows the electroreduction catalytic performance of the catalyst obtained in Example 1 at different voltages.

[0026] Figure 5 The graph shows the electroreduction catalytic performance of copper oxide in Example 1 at different voltages.

[0027] Figure 6 The graph shows the electroreduction catalytic performance of single-atom copper oxide without nitrogen-coordinating active sites in Example 2 under different voltages. Detailed Implementation

[0028] This invention provides a copper oxide nanosheet catalyst supported on metal single-atom coordination compounds, comprising copper oxide nanosheets and molecules containing metal single atoms supported on the surface of the copper oxide nanosheets. The metal single-atom-containing molecules include one or more of the following: iron phthalocyanine, nickel phthalocyanine, cobalt phthalocyanine, copper phthalocyanine, zinc phthalocyanine, titanium phthalocyanine, manganese phthalocyanine, lead phthalocyanine, tin phthalocyanine, platinum phthalocyanine, vanadium phthalocyanine, magnesium phthalocyanine, indium phthalocyanine, bismuth phthalocyanine, aluminum phthalocyanine chloride, gallium phthalocyanine chloride, titanium phthalocyanine, vanadium phthalocyanine, tin dichlorophthalocyanine, cobalt phthalocyanine sulfonated, and their phthalocyanine metal derivatives.

[0029] The copper oxide nanosheet catalyst supported on metal single-atom coordination of the present invention combines molecules containing metal single atoms with copper oxide nanosheets. Through the synergistic effect of the nitrogen coordination active sites of the metal single atoms and the defects of copper oxide, it is beneficial to stabilize the adsorption and aggregation of intermediate *CO on the surface of copper oxide, promote carbon-carbon coupling, enhance the catalyst's catalytic activity for carbon dioxide electroreduction, and improve the selectivity for C2 products.

[0030] In this invention, the copper oxide nanosheets are preferably two-dimensional planar structures, and the average thickness of the two-dimensional planar structures is preferably 10-20 nm, more preferably 15 nm.

[0031] In this invention, the molecule containing a single metal atom preferably includes iron phthalocyanine and cobalt phthalocyanine.

[0032] In this invention, the mass ratio of iron phthalocyanine to cobalt phthalocyanine is preferably 1:1.

[0033] This invention also provides a method for preparing the copper oxide nanosheet catalyst supported on metal single-atom coordination structures as described above, comprising the following steps:

[0034] A precursor is obtained by mixing a copper salt solution, a strong alkaline solution, and a molecule containing a single metal atom.

[0035] The precursor was subjected to hydrothermal treatment followed by solid-liquid separation, washing, and freeze-drying to obtain the copper oxide nanosheet catalyst supported on metal single-atom coordination compounds.

[0036] Unless otherwise specified, all raw materials used in this invention are commercially available products in the field.

[0037] This invention involves mixing a copper salt solution, a strong alkaline solution, and a molecule containing a single metal atom to obtain a precursor.

[0038] In this invention, the molecule containing a single metal atom reacts with Cu in the copper salt solution. 2+ The preferred molar ratio is 1:10 to 1:100000.

[0039] In this invention, the copper salt in the copper salt solution preferably includes one or more of copper nitrate, copper sulfate, copper fluoride, copper chloride, copper bromide, and copper acetate.

[0040] In this invention, the copper salt solution contains Cu 2+ With OH in strong alkaline solutions - The preferred molar ratio is 1:2 to 1:20, and more preferably 1:4.

[0041] In this invention, the copper salt solution contains Cu 2+ The preferred molar concentration is 0.001–10 mol / L.

[0042] In this invention, the strong base in the strong base solution preferably includes one or more of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, and quaternary ammonium bases.

[0043] In this invention, the strong alkaline solution contains OH- - The preferred molar concentration is 0.001–10 mol / L.

[0044] In this invention, the mixing is preferably performed by stirring and sonication in sequence, the stirring time is preferably 0.1 to 12 hours, and the sonication time is preferably 0.5 to 24 hours.

[0045] After obtaining the precursor, the present invention performs hydrothermal treatment on the precursor and then sequentially performs solid-liquid separation, washing and freeze-drying to obtain the copper oxide nanosheet catalyst supported on metal single-atom coordination compounds.

[0046] In this invention, the temperature of the hydrothermal treatment is preferably 60-120°C, more preferably 90-100°C, and the time is preferably 2-24 hours, more preferably 4-8 hours.

[0047] In this invention, the solid-liquid separation is preferably performed by centrifugation.

[0048] The present invention does not impose any particular limitation on the specific methods of washing and freeze-drying, and any method known to those skilled in the art can be used.

[0049] The present invention also provides the application of the copper oxide nanosheet catalyst supported on metal single-atom coordination compounds as described in the above technical solutions or the copper oxide nanosheet catalyst supported on metal single-atom coordination compounds prepared by the preparation method described in the above technical solutions in the field of carbon dioxide electroreduction catalysis.

[0050] In this invention, carbon paper treated with copper oxide nanosheet catalyst supported on metal single-atom coordination compounds is preferably used as the working electrode, and CO2 is electro-reduced to C2 product through a three-electrode system.

[0051] To further illustrate the present invention, the following detailed description, in conjunction with examples, of the copper oxide nanosheet catalyst supported on metal single-atom coordination, its preparation method, and its application, is provided by the present invention, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0052] Example 1

[0053] The specific preparation steps are as follows:

[0054] Weigh out 0.85g of CuCl2·2H2O and 0.8g of NaOH (CuCl2·2H2O). 2+ With OH - The mixing molar ratio was 1:4. CuCl2·2H2O and NaOH were dissolved in 20 mL of deionized water to obtain the corresponding aqueous solutions. The CuCl2 solution was added to the NaOH solution, stirred and reacted at room temperature for 0.5 h to obtain a Cu(OH)2 precursor suspension. 0.005 g of sulfonated cobalt phthalocyanine (CoSPc) was added to the Cu(OH)2 suspension and stirred for 1 h, followed by sonication for 1 h. After sonication, the mixture was stirred again for 1 h. The mixture was then transferred to an autoclave, sealed, and heat-treated at 100 °C for 2 h. After cooling to room temperature, the mixture was removed. The product was washed repeatedly by centrifugation with deionized water and ethanol to remove residual alkali and salt. The product was then freeze-dried under vacuum to finally obtain the catalyst.

[0055] The catalyst prepared by the above method was applied to the electrocatalytic reduction of carbon dioxide to ethylene: An electrolytic cell divided into an anode and a cathode by a proton exchange membrane was used. The catalyst prepared by the above method was used as the working electrode (cathode), a platinum sheet as the counter electrode (anode), and a saturated calomel electrode as the reference electrode (cathode). A 0.1 mol / L KHCO3 electrolyte solution was added to both the anode and cathode cells. CO2 was introduced into the cathode cell until saturation. Then, under continuous CO2 introduction, CO2 was reduced at a constant potential. The potential control range for the constant potential reduction process was -1.2 to -2.0 V (vs. SCE). The Faraday efficiency for the electrocatalytic reduction of CO2 to C2H6 at a constant voltage of -1.8 V (vs. SCE) was 49.1%.

[0056] The catalyst prepared in Example 1 was subjected to morphological, structural, and compositional analysis, and the obtained spectra are shown in the figure. Figures 1-3 .

[0057] Figure 1 The images show scanning electron microscope (SEM) images of the catalyst obtained in Example 1 at different magnifications. As can be seen from the images, the prepared catalyst has a two-dimensional sheet-like structure with a relatively rough surface and some defects. The average thickness is 10-20 nm.

[0058] Figure 2The image shows the elemental analysis (EDX) diagram of the catalyst obtained in Example 1. As can be seen from the image, cobalt is evenly distributed in the catalyst.

[0059] Figure 3 The figure shows the X-ray diffraction (XRD) pattern of the catalyst obtained in Example 1. As can be seen from the figure, the XRD patterns of the catalyst and CuO are quite similar, and there are no obvious diffraction peaks of cobalt and its complexes, indicating that the cobalt content in the catalyst is low and it is distributed in single atoms.

[0060] Comparative Example 1

[0061] Copper oxide without single atoms was prepared according to the method of Example 1, with the specific operation steps being the same, except that cobalt sulfonated phthalocyanine (CoSPc) was not added, resulting in copper oxide of Comparative Example 1. Electrocatalytic testing was performed using the same method, and the Faraday efficiency for the electrocatalytic reduction of CO2 to C2H6 at a constant voltage of -1.8V (vs. SCE) was 17.8%.

[0062] Comparative Example 2

[0063] The specific operational steps for preparing nitrogen-free, coordinated-active-site-free single-atom copper oxide according to the method of Example 1 are the same, except that 0.005 g of sulfonated cobalt phthalocyanine (CoSPc) is replaced with 0.0015 g of CoCl2·6H2O, resulting in nitrogen-free, coordinated-active-site-free single-atom copper oxide as in Comparative Example 2. Electrocatalytic testing was performed using the same method, and the Faraday efficiency for the electrocatalytic reduction of CO2 to C2H6 at a constant voltage of -1.8 V (vs. SCE) was 25.7%.

[0064] Figure 4 The graph shows the electroreduction catalytic performance of the catalyst obtained in Example 1 at different voltages. Figure 5 The graph shows the electroreduction catalytic performance of copper oxide in Example 1 at different voltages. Figure 6 To compare the electroreduction catalytic performance of single-atom copper oxide without nitrogen-coordinating active sites in Example 2 under different voltages, the following was conducted: Figures 4-6 The comparison of product data shows that the electroreduction catalytic performance of the product prepared in Example 1 is significantly better than that of copper oxide without single-atom monoxide and copper oxide without nitrogen coordination active sites.

[0065] Example 2

[0066] Weigh out 0.85g of CuCl2·2H2O and 0.8g of NaOH (CuCl2·2H2O). 2+ With OH -The mixing molar ratio was 1:4. CuCl2·2H2O and NaOH were dissolved in 20 mL of deionized water to obtain the corresponding aqueous solutions. The CuCl2 solution was added to the NaOH solution, stirred and reacted at room temperature for 0.5 h to obtain a Cu(OH)2 precursor suspension. 0.005 g of sulfonated cobalt phthalocyanine (CoSPc) was added to the Cu(OH)2 suspension and stirred for 1 h, followed by sonication for 1 h. After sonication, the mixture was stirred again for 1 h. The mixture was then transferred to an autoclave, sealed, and heat-treated at 100 °C for 2 h. After cooling to room temperature, the mixture was removed. The product was washed repeatedly by centrifugation with deionized water and ethanol to remove residual alkali and salt. The product was then freeze-dried under vacuum to finally obtain the catalyst.

[0067] The catalyst prepared by the above method was applied to the electrocatalytic reduction of carbon dioxide to ethylene: An electrolytic cell divided into an anode and a cathode by a proton exchange membrane was used. The catalyst prepared by the above method was used as the working electrode (cathode), a platinum sheet as the counter electrode (anode), and a saturated calomel electrode as the reference electrode (cathode). A 0.1 mol / L KHCO3 electrolyte solution was added to both the anode and cathode cells. CO2 was introduced into the cathode cell until saturation. Then, under continuous CO2 introduction, CO2 was reduced at a constant potential. The potential control range for the constant potential reduction process was -1.2 to -2.0 V (vs. SCE). The Faraday efficiency for the electrocatalytic reduction of CO2 to C2H6 at a constant voltage of -1.8 V (vs. SCE) was 56.8%.

[0068] Example 3

[0069] The specific preparation method is as follows:

[0070] Weigh out 0.85g of CuCl2·2H2O and 0.8g of NaOH (CuCl2·2H2O). 2+ With OH - The mixing molar ratio was 1:4. CuCl2·2H2O and NaOH were dissolved in 20 mL of deionized water to obtain the corresponding aqueous solutions. The CuCl2 solution was added to the NaOH solution, stirred and reacted at room temperature for 0.5 h to obtain a Cu(OH)2 precursor suspension. 0.5 g of sulfonated cobalt phthalocyanine (CoSPc) was added to the Cu(OH)2 suspension and stirred for 1 h, followed by sonication for 1 h. After sonication, the mixture was stirred again for 1 h. The mixture was then transferred to an autoclave, sealed, and heat-treated at 100 °C for 2 h. After cooling to room temperature, the mixture was removed. The product was washed repeatedly by centrifugation with deionized water and ethanol to remove residual alkali and salt. The product was then freeze-dried under vacuum to finally obtain the catalyst.

[0071] The catalyst prepared by the above method was applied to the electrocatalytic reduction of carbon dioxide to ethylene: An electrolytic cell divided into an anode and a cathode by a proton exchange membrane was used. The catalyst prepared by the above method was used as the working electrode (cathode), a platinum sheet as the counter electrode (anode), and a saturated calomel electrode as the reference electrode (cathode). A 0.1 mol / L KHCO3 electrolyte solution was added to both the anode and cathode cells. CO2 was introduced into the cathode cell until saturation. Then, under continuous CO2 introduction, CO2 was reduced at a constant potential. The potential control range for the constant potential reduction process was -1.2 to -2.0 V (vs. SCE). The Faraday efficiency for the electrocatalytic reduction of CO2 to C2H6 at a constant voltage of -1.8 V (vs. SCE) was 61.2%.

[0072] Example 4

[0073] The specific preparation method is as follows:

[0074] Weigh out 0.85g of CuCl2·2H2O and 0.8g of NaOH (CuCl2·2H2O). 2+ With OH - The mixing molar ratio was 1:4. CuCl2·2H2O and NaOH were dissolved in 20 mL of deionized water to obtain the corresponding aqueous solutions. The CuCl2 solution was added to the NaOH solution, stirred and reacted at room temperature for 0.5 h to obtain a Cu(OH)2 precursor suspension. 1 g of sulfonated cobalt phthalocyanine (CoSPc) was added to the Cu(OH)2 suspension and stirred for 1 h, followed by sonication for 1 h. After sonication, the mixture was stirred again for 1 h. The mixture was then transferred to an autoclave, sealed, and heat-treated at 100 °C for 2 h. After cooling to room temperature, the mixture was removed. The product was washed repeatedly by centrifugation with deionized water and ethanol to remove residual alkali and salt. The product was then freeze-dried under vacuum to finally obtain the catalyst.

[0075] The catalyst prepared by the above method was applied to the electrocatalytic reduction of carbon dioxide to ethylene: An electrolytic cell divided into an anode and a cathode by a proton exchange membrane was used. The catalyst prepared by the above method was used as the working electrode (cathode), a platinum sheet as the counter electrode (anode), and a saturated calomel electrode as the reference electrode (cathode). A 0.1 mol / L KHCO3 electrolyte solution was added to both the anode and cathode cells. CO2 was introduced into the cathode cell until saturation. Then, under continuous CO2 introduction, CO2 was reduced at a constant potential. The potential control range for the constant potential reduction process was -1.2 to -2.0 V (vs. SCE). The Faraday efficiency for the electrocatalytic reduction of CO2 to C2H6 at a constant voltage of -1.8 V (vs. SCE) was 57.5%.

[0076] Example 5

[0077] The specific preparation method is as follows:

[0078] Weigh out 9.67g of Cu(NO3)2·3H2O and 22.44g of KOH(Cu) 2+ With OH - The mixing molar ratio of Cu(NO3)2·3H2O and KOH were dissolved in 50 mL of deionized water to obtain the corresponding aqueous solutions. The Cu(NO3)2 solution was added to the KOH solution, stirred and reacted at room temperature for 2 h to obtain a Cu(OH)2 precursor suspension. 0.01 g of iron phthalocyanine (FePc) was added to the Cu(OH)2 suspension and stirred for 1.5 h, followed by ultrasonic treatment for 1.5 h. After ultrasonic treatment, the mixture was stirred again for 1.5 h. The mixture was then transferred to an autoclave and sealed. It was heat-treated at 90 °C for 4 h and cooled to room temperature before being removed. The product was washed repeatedly by centrifugation with deionized water and ethanol to remove residual alkali and salt. The product was then freeze-dried under vacuum to finally obtain the catalyst.

[0079] The catalyst prepared by the above method was applied to the electrocatalytic reduction of carbon dioxide to ethylene: An electrolytic cell divided into an anode and a cathode by a proton exchange membrane was used. The catalyst prepared by the above method was used as the working electrode (cathode), a platinum sheet as the counter electrode (anode), and a saturated calomel electrode as the reference electrode (cathode). A 0.1 mol / L KHCO3 electrolyte solution was added to both the anode and cathode cells. CO2 was introduced into the cathode cell until saturation. Then, under continuous CO2 introduction, CO2 was reduced at a constant potential. The potential control range for the constant potential reduction process was -1.2 to -2.0 V (vs. SCE). The Faraday efficiency for the electrocatalytic reduction of CO2 to C2H6 at a constant voltage of -1.8 V (vs. SCE) was 55.3%.

[0080] Example 6

[0081] The specific preparation method is as follows:

[0082] Weigh out 62.5g of CuSO4·5H2O and 115g of LiOH(Cu) 2+ With OH -The mixing molar ratio was 1:20. CuSO4·5H2O and LiOH were dissolved in 200 mL of deionized water to obtain the corresponding aqueous solutions. The CuSO4 solution was added to the LiOH solution, stirred and reacted at room temperature for 5 h to obtain the precursor Cu(OH)2 suspension. 0.05 g of aluminum phthalocyanine chloride (AlClPc) was added to the Cu(OH)2 suspension and stirred for 3 h, followed by ultrasonic treatment for 2 h. After ultrasonic treatment, the mixture was stirred again for 3 h. The mixture was transferred to an autoclave and sealed. It was heat-treated at 120 °C for 8 h and then cooled to room temperature before being removed. The product was washed repeatedly by centrifugation with deionized water and ethanol to remove residual alkali and salt. The product was then freeze-dried under vacuum to finally obtain the catalyst.

[0083] The catalyst prepared by the above method was applied to the electrocatalytic reduction of carbon dioxide to ethylene: An electrolytic cell divided into an anode and a cathode by a proton exchange membrane was used. The catalyst prepared by the above method was used as the working electrode (cathode), a platinum sheet as the counter electrode (anode), and a saturated calomel electrode as the reference electrode (cathode). A 0.1 mol / L KHCO3 electrolyte solution was added to both the anode and cathode cells. CO2 was introduced into the cathode cell until saturation. Then, under continuous CO2 introduction, CO2 was reduced at a constant potential. The potential control range for the constant potential reduction process was -1.2 to -2.0 V (vs. SCE). The Faraday efficiency for the electrocatalytic reduction of CO2 to C2H6 at a constant voltage of -1.8 V (vs. SCE) was 52.2%.

[0084] Example 7

[0085] The specific preparation method is as follows:

[0086] Weigh out 9.67g of Cu(NO3)2·3H2O and 22.44g of KOH(Cu) 2+ With OH - The mixing molar ratio of Cu(NO3)2·3H2O and KOH were dissolved in 50 mL of deionized water to obtain the corresponding aqueous solutions. The Cu(NO3)2 solution was added to the KOH solution, stirred and reacted at room temperature for 2 h to obtain a Cu(OH)2 precursor suspension. 0.01 g of iron phthalocyanine (FePc) and 0.01 g of cobalt phthalocyanine (CoPc) were added to the Cu(OH)2 suspension and stirred for 1.5 h, followed by ultrasonic treatment for 1.5 h. After ultrasonic treatment, the mixture was stirred again for 1.5 h. The mixture was then transferred to an autoclave, sealed, and heat-treated at 90 °C for 4 h. After cooling to room temperature, the mixture was removed. The product was washed repeatedly by centrifugation with deionized water and ethanol to remove residual alkali and salt. The product was then freeze-dried under vacuum to finally obtain the catalyst.

[0087] The catalyst prepared by the above method was applied to the electrocatalytic reduction of carbon dioxide to ethylene: An electrolytic cell divided into an anode and a cathode by a proton exchange membrane was used. The catalyst prepared by the above method was used as the working electrode (cathode), a platinum sheet as the counter electrode (anode), and a saturated calomel electrode as the reference electrode (cathode). A 0.1 mol / L KHCO3 electrolyte solution was added to both the anode and cathode cells. CO2 was introduced into the cathode cell until saturation. Then, under continuous CO2 introduction, CO2 was reduced at a constant potential. The potential control range for the constant potential reduction process was -1.2 to -2.0 V (vs. SCE). The Faraday efficiency for the electrocatalytic reduction of CO2 to C2H6 at a constant voltage of -1.8 V (vs. SCE) was 56.7%.

[0088] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A copper oxide nanosheet catalyst supported on metal single-atom coordination compounds, characterized in that, The preparation method of the copper oxide nanosheet catalyst supported on metal single-atom coordination compounds includes the following steps: A copper salt solution, a strong alkaline solution, and sulfonated cobalt phthalocyanine were mixed to obtain the precursor; The precursor was subjected to hydrothermal treatment followed by solid-liquid separation, washing, and freeze-drying to obtain the copper oxide nanosheet catalyst supported on metal single-atom coordination compounds.

2. The copper oxide nanosheet catalyst supported on metal single-atom coordination compounds according to claim 1, characterized in that, The average thickness of the copper oxide nanosheets is 10~20 nm.

3. The copper oxide nanosheet catalyst supported on metal single-atom coordination structures according to claim 1, characterized in that, The copper salt in the copper salt solution is CuCl2·2H2O, the mass of CuCl2·2H2O is 0.85g, and the mass of sulfonated cobalt phthalocyanine is 0.5g.

4. A method for preparing a copper oxide nanosheet catalyst supported on metal single-atom coordination structures according to any one of claims 1 to 3, characterized in that, Includes the following steps: A copper salt solution, a strong alkaline solution, and sulfonated cobalt phthalocyanine were mixed to obtain the precursor; The precursor was subjected to hydrothermal treatment followed by solid-liquid separation, washing, and freeze-drying to obtain the copper oxide nanosheet catalyst supported on metal single-atom coordination compounds.

5. The preparation method according to claim 4, characterized in that, Cu in copper salt solution 2+ With OH in strong alkaline solutions - The molar ratio is 1:2 to 1:

20.

6. The preparation method according to claim 4, characterized in that, The hydrothermal treatment is performed at a temperature of 60~120 ℃ for a duration of 2~24 h.

7. The preparation method according to claim 4 or 6, characterized in that, The hydrothermal treatment is performed at a temperature of 90-100℃ for 4-8 hours.

8. The preparation method according to claim 4, characterized in that, The copper salt in the copper salt solution is CuCl2·2H2O, the mass of CuCl2·2H2O is 0.85g, and the mass of sulfonated cobalt phthalocyanine is 0.5g.

9. The application of the copper oxide nanosheet catalyst supported on metal single-atom coordination as described in any one of claims 1 to 3, or the copper oxide nanosheet catalyst supported on metal single-atom coordination as described in any one of claims 4 to 8, in the field of carbon dioxide electroreduction catalysis.

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