An AgCl / CuO nanocatalyst and its preparation method

Abstract

The present invention relates to the technical field of nano-catalysts, and discloses a preparation method of an AgCl / CuO nano-catalyst, which comprises the following steps: using a copper source and a silver metal salt as raw materials, deionized water as a solvent, adding an alkali source, synthesizing an AgCl / Cu(OH)₂ nano-material, and then obtaining the AgCl / CuO nano-catalyst through calcination. The more specific steps are as follows: Step 1: Dissolve 0.2 mmol of copper chloride dihydrate in 25 mL of deionized water and stir evenly, then add 2 mL of 16 M alkali source to the previous solution, and stir well for 30 minutes to obtain a Cu(OH)₂ aqueous solution; Step 2: Dissolve 0.085 g of silver nitrate solid in 10 mL of deionized water to obtain a 0.05 M silver nitrate aqueous solution. The method for preparing the AgCl / CuO nano-catalyst provided by the present invention has a simple process, mild reaction conditions, and cheap raw materials. The prepared catalyst has a unique nano-ribbon morphology, can be synthesized in large quantities, and has a broad application prospect in actual large-scale industrial applications.

Description

Technical Field

[0001] The present invention relates to the technical field of nano-catalysts, and particularly to an AgCl / CuO nano-catalyst and a preparation method thereof. Background Art

[0002] The large emission of greenhouse gas carbon dioxide (CO2) has caused severe negative impacts on the global climate and energy economy. Therefore, the development of efficient and clean CO2 catalytic technologies to convert it into high-value chemical products has attracted extensive attention from scientific researchers. Using renewable electric energy to turn CO2 into a valuable resource provides an effective solution for carbon emission reduction and energy storage, and the core lies in how to develop efficient electrocatalysts.

[0003] Research shows that metal oxide electrocatalysts can selectively reduce carbon dioxide to C1 products, such as methanol, carbon monoxide, etc. However, for the production of C 2+ products, especially ethylene products with higher energy density, there are still problems such as low selectivity and poor stability. This is because the process of reducing CO2 to produce ethylene involves the generation of various reactive intermediates, which leads to the diversity of reduction products. Therefore, the development of metal oxide electrocatalysts with high ethylene selectivity is still challenging.

[0004] Currently, copper-based oxide nano-catalysts have become the most popular catalytic materials for electro-reducing CO2 to produce ethylene products due to their high CO2 conversion activity and suitable binding energy for carbon-containing intermediates. Recent research shows that the doping effect of other metal or non-metal components can optimize the electronic structure of copper oxide catalysts, stabilize the adsorption of intermediate *CO, and reduce the reaction barrier of C-C coupling, realizing the high-selectivity generation of C 2+ products. However, traditional copper oxide doping strategies often require harsh reaction conditions.

[0005] Therefore, the present invention proposes a simple, large-scale, and mild preparation method for an AgCl / CuO electrocatalyst. The special porous nanobelt morphology of CuO in the preparation process provides more space for the loading of AgCl, which is beneficial to the better adsorption of carbon dioxide molecules during the electrocatalysis of carbon dioxide, and is used for highly selectively and actively catalyzing the reduction of CO2 to produce ethylene. At the same time, the ethylene produced in the electro-reduction of CO2 has a Faraday efficiency as high as 72%. Summary of the Invention

[0006] To solve the technical problems proposed in the background art, the present invention provides a preparation method for an AgCl / CuO nano-catalyst.

[0007] The present invention is implemented by the following technical solutions: The preparation of an AgCl / CuO nanocatalyst, wherein: CuO exists in the form of nanobelts with a porous structure and a high grain boundary density, and AgCl nanoparticles are uniformly distributed on the CuO nanobelt support, which can expose more active sites. The raw materials of this catalyst are low in price, the preparation process is simple, the reaction conditions are mild, and the prepared catalyst shows excellent high activity, stability, and high selectivity (the Faraday efficiency of ethylene is as high as 72%) when applied to electrochemical ethylene production tests in a neutral electrolyte.

[0008] A method for preparing an AgCl / CuO nanocatalyst proposed by the present invention includes the following steps:

[0009] Using a copper source and a silver metal salt as raw materials, deionized water as a solvent, and adding a base source to synthesize an AgCl / Cu(OH)2 nanomaterial, and then obtaining the AgCl / CuO nanocatalyst through calcination.

[0010] The more specific steps are as follows:

[0011] Step 1: Dissolve 0.2 mmol of copper dichloride dihydrate or copper nitrate trihydrate in 25 mL of deionized water and stir evenly, then add 2 mL of 16 M base source to the previous solution and stir well for 30 minutes to obtain a Cu(OH)2 aqueous solution;

[0012] Step 2: Dissolve 0.085 g of silver nitrate solid in 10 mL of deionized water to obtain a 0.05 M silver nitrate aqueous solution;

[0013] Step 3: Add 1 mL of 0.05 M AgNO3 aqueous solution to the Cu(OH)2 solution prepared in Step 1. After reacting for 10 minutes, wash with deionized water, ethanol, and cyclohexane respectively, and then ultrasonically disperse it evenly in 5 mL of cyclohexane and perform freeze-drying overnight to obtain an AgCl / Cu(OH)2 precursor;

[0014] Step 4: Calcinate the obtained AgCl / Cu(OH)2 precursor at 250 °C for 10 min to obtain the AgCl / CuO nanocatalyst.

[0015] Preferably, the base source is taken from any one of potassium hydroxide, sodium hydroxide, and ethylenediamine.

[0016] Preferably, the copper dichloride dihydrate, copper nitrate trihydrate, silver nitrate, sodium hydroxide, potassium hydroxide, and ethylenediamine are all of analytical purity.

[0017] Preferably, the molar ratio of AgCl to CuO in the AgCl / CuO nanocatalyst is 1:4, that is, 25% AgCl / CuO.

[0018] Preferably, the washing method is to wash with deionized water, ethanol, cyclohexane, centrifuge, store in cyclohexane, and store after vacuum drying.

[0019] Preferably, in step 3, the mixing method of silver nitrate and copper hydroxide (i.e., copper source and base source) is the liquid-phase physical mixing method to prepare the required AgCl / Cu(OH)₂ precursor.

[0020] Preferably, the calcination is carried out in air, and the obtained catalyst material is stored under normal temperature and dry conditions.

[0021] The present invention also proposes a method for electrocatalytic water splitting to produce ethylene, and the specific steps are as follows:

[0022] Weigh 1 mg of the AgCl / CuO catalyst prepared by the above method and disperse it in 0.1 mL of a mixed solution containing isopropanol and naphthol with a volume ratio of 9:1, and ultrasonically disperse for 30 min to obtain a uniformly dispersed mixed solution;

[0023] Use a pipette gun with a measuring range of 10 μL to take 4 μL of the uniformly dispersed mixed solution and drop-coat it on a glassy carbon electrode with an area of 3 x 3 mm² in two times. The glassy carbon electrode coated with the catalyst is directly used as the working electrode after drying, and an Ag / AgCl electrode is used as the reference electrode, and a 1 x 1 cm² platinum sheet electrode is used as the counter electrode to form a three-electrode system, and electrocatalytic water splitting to produce ethylene is tested in an electrolyte of 0.5 M KHCO₃.

[0024] At the beginning of the test, specifically, the AgCl / CuO catalyst needs to be reconstructed at a potential of -1.1 V (vs. RHE) for 30 min before coating to obtain the Ag / Cu catalyst. In the test, linear sweep voltammetry (LSV) is used to explore the electrocatalytic activity of the catalyst, and the stability of the catalyst is illustrated by testing the change of current with time at a fixed potential through the potentiostatic method, and the performance of the catalyst prepared in the present invention is compared with the performance of other CuO-related catalysts.

[0025] Preferably, the mass of the catalyst loaded on the glassy carbon electrode is 0.04 mg, the scan rate of LSV is 10 mV / s, and the test potential range is -2 to 0 V.

[0026] Adopting the above technical solution, at room temperature, using a copper source (copper dichloride dihydrate, copper nitrate trihydrate) and a silver metal salt as raw materials, deionized water as a solvent, and adding a base source (such as potassium hydroxide, sodium hydroxide, ethylenediamine), an AgCl / Cu(OH)₂ nanomaterial is synthesized, and then an AgCl / CuO nanocatalyst is obtained through calcination.

[0027] The preparation process is simple and novel, with mild reaction conditions and short time consumption. The prepared composite catalyst has unique morphological characteristics; it can efficiently and rapidly reduce CO2 in the atmosphere to organic chemical raw materials such as carbon monoxide, methane, and ethylene, and shows excellent Faraday efficiency in the production of ethylene. Therefore, the synthesis method of this AgCl / CuO catalyst has important application value in large-scale industrial practical applications.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] The method for providing the AgCl / CuO nanocatalyst of the present invention has a simple process, mild reaction conditions, and cheap raw materials. The prepared catalyst has a unique nanobelt morphology, can be synthesized in large quantities, and has broad application prospects in large-scale industrial practical applications.

[0030] The catalyst prepared by the present invention is applied to the electrochemical production of ethylene in a neutral electrolyte and shows excellent high activity, stability, and high selectivity (the Faraday efficiency of ethylene is as high as 72%), and has great advantages over the catalytic CO2 reduction performance and selectivity of the currently reported CuO-related catalysts. Description of the Drawings

[0031] Figure 1 is a flow chart of a method for preparing an AgCl / CuO nanocatalyst proposed by the present invention;

[0032] Figure 2 is a synthesis picture of a 25% AgCl / Cu(OH)2 precursor nanomaterial with a molar ratio involved in the present invention;

[0033] Figure 3 is a transmission electron microscope (STEM-EDS) image of a 25% AgCl / Cu(OH)2 nanomaterial with a molar ratio involved in the present invention;

[0034] Figure 4 is a comparative transmission electron microscope (STEM-EDS) image of Cu(OH)2 powder and 25% AgCl / CuO powder with a molar ratio involved in the present invention;

[0035] Figure 5 is a transmission electron microscope (STEM-EDS) image of Ag / Cu powder after reconstruction for 30 min at -1.1 V (vs. RHE) of the catalyst involved in the present invention;

[0036] Figure 6 is a HRTEM image of 25% AgCl / CuO powder with a molar ratio involved in the present invention;

[0037] Figure 7These are the X-ray diffraction (XRD) patterns of the AgCl / CuO catalysts with molar ratios of 1%, 10%, 25%, 50%, and 100% respectively (corresponding to Sample 1, Sample 2, Sample 3, Sample 4, and Sample 5 in sequence) of the present invention;

[0038] Figure 8 These are the X-ray diffraction (XRD) patterns of the 25% AgCl / CuO catalyst and its precursor AgCl / Cu(OH)₂ with a molar ratio of the present invention;

[0039] Figure 9 These are the linear sweep voltammetry (LSV) curves of the AgCl / CuO powders with molar ratios of 1%, 10%, 25%, 50%, and 100% respectively (corresponding to Sample 1, Sample 2, Sample 3, Sample 4, and Sample 5 in sequence) of the present invention;

[0040] Figure 10 These are the linear sweep voltammetry (LSV) curves of the 25% AgCl / CuO powder synthesized from copper chloride dihydrate and copper nitrate trihydrate of the present invention;

[0041] Figure 11 These are the performance graphs of the AgCl / CuO powder catalysts with molar ratios of 1%, 10%, 25%, 50%, and 100% respectively (corresponding to Sample 1, Sample 2, Sample 3, Sample 4, and Sample 5 in sequence) of the present invention at -1 V (vs. RHE);

[0042] Figure 12 These are the performance graphs of the 25% AgCl / CuO powder with different potentials of the present invention;

[0043] Figure 13 These are the Fourier transform infrared spectroscopy (FT-IR) graphs of the 25% AgCl / CuO powder with a molar ratio of the present invention. Detailed implementation manners

[0044] Next, in combination with the accompanying drawings and specific implementation manners, the present invention will be further described. It should be noted that, on the premise of no conflict, any combination of the following described embodiments or technical features can form a new embodiment.

[0045] Example 1:

[0046] Referring to Figure 1 , a preparation method of an AgCl / CuO nanocatalyst proposed in this solution includes the following steps:

[0047] Step 1: Dissolve 0.2 mmol of copper chloride dihydrate in 25 mL of deionized water and stir evenly. Then, prepare 2 mL of 16 M aqueous sodium hydroxide solution and add it to the previous solution. Stir well for 30 minutes to obtain an aqueous solution of Cu(OH)₂.

[0048] Step 2: Dissolve 0.085 g of silver nitrate solid in 10 mL of deionized water to obtain a 0.05 M aqueous silver nitrate solution.

[0049] Step 3: Add 1 mL of 0.05 M AgNO₃ aqueous solution to the prepared Cu(OH)₂ solution above. After reacting for 10 minutes, wash it with deionized water, ethanol, and cyclohexane respectively, and then ultrasonically disperse it evenly in 5 mL of cyclohexane, followed by freeze-drying overnight to obtain the AgCl / Cu(OH)₂ precursor.

[0050] Step 4: Calcinate the obtained AgCl / Cu(OH)₂ precursor at 250 °C for 10 min to obtain the AgCl / CuO nanocatalyst.

[0051] Example 2:

[0052] A preparation method of an AgCl / CuO nanocatalyst proposed in this scheme includes the following steps:

[0053] Step 1: Dissolve 0.2 mmol of copper nitrate trihydrate in 25 mL of deionized water and stir evenly. Then, prepare 2 mL of 16 M aqueous sodium hydroxide solution and add it to the previous solution. Stir well for 30 minutes to obtain an aqueous solution of Cu(OH)₂.

[0054] Step 2: Dissolve 0.085 g of silver nitrate solid in 10 mL of deionized water to obtain a 0.05 M aqueous silver nitrate solution.

[0055] Step 3: Add 1 mL of 0.05 M AgNO₃ aqueous solution to the prepared Cu(OH)₂ solution above. After reacting for 10 minutes, wash it with deionized water, ethanol, and cyclohexane respectively, and then ultrasonically disperse it evenly in 5 mL of cyclohexane, followed by freeze-drying overnight to obtain the AgCl / Cu(OH)₂ precursor.

[0056] Step 4: Calcinate the obtained AgCl / Cu(OH)₂ precursor at 250 °C for 10 min to obtain the AgCl / CuO nanocatalyst.

[0057] Example 3:

[0058] A preparation method of an AgCl / CuO nanocatalyst proposed in this scheme includes the following steps:

[0059] Step 1: Dissolve 0.2 mmol of copper chloride dihydrate in 25 mL of deionized water and stir evenly. Then, prepare 2 mL of 16 M potassium hydroxide aqueous solution and add it to the previous solution. Stir well for 30 minutes to obtain an aqueous solution of Cu(OH)₂.

[0060] Step 2: Dissolve 0.085 g of silver nitrate solid in 10 mL of deionized water to obtain a 0.05 M silver nitrate aqueous solution.

[0061] Step 3: Add 1 mL of 0.05 M AgNO₃ aqueous solution to the prepared Cu(OH)₂ solution. After reacting for 10 minutes, wash it with deionized water, ethanol, and cyclohexane respectively, and then ultrasonically disperse it evenly in 5 mL of cyclohexane. Conduct freeze-drying overnight to obtain the AgCl / Cu(OH)₂ precursor.

[0062] Step 4: Calcinate the obtained AgCl / Cu(OH)₂ precursor at 250 °C for 10 min to obtain the AgCl / CuO nanocatalyst.

[0063] Example 4:

[0064] A preparation method of an AgCl / CuO nanocatalyst proposed in this scheme includes the following steps:

[0065] Step 1: Dissolve 0.2 mmol of copper chloride dihydrate in 25 mL of deionized water and stir evenly. Then, prepare 2 mL of 16 M ethylenediamine aqueous solution and add it to the previous solution. Stir well for 30 minutes to obtain an aqueous solution of Cu(OH)₂.

[0066] Step 2: Dissolve 0.085 g of silver nitrate solid in 10 mL of deionized water to obtain a 0.05 M silver nitrate aqueous solution.

[0067] Step 3: Add 1 mL of 0.05 M AgNO₃ aqueous solution to the prepared Cu(OH)₂ solution. After reacting for 10 minutes, wash it with deionized water, ethanol, and cyclohexane respectively, and then ultrasonically disperse it evenly in 5 mL of cyclohexane. Conduct freeze-drying overnight to obtain the AgCl / Cu(OH)₂ precursor.

[0068] Step 4: Calcinate the obtained AgCl / Cu(OH)₂ precursor at 250 °C for 10 min to obtain the AgCl / CuO nanocatalyst.

[0069] Test Example 1:

[0070] Use the AgCl / CuO nanocatalyst prepared in Example 1 for the test of electrocatalytic water splitting to produce ethylene.

[0071] First, pre-treat the glassy carbon electrode: Polish the glassy carbon electrode in an "8" shape on suede with alumina powder for 2 - 3 minutes, then wash the electrode surface with deionized water to remove the polishing residues. After that, the glassy carbon electrode needs to be activated by cyclic voltammetry in a 0.5 - 1 mol / L H2SO4 solution, with a scanning range of -1 to 1 V, and scanned repeatedly until a stable cyclic voltammogram is obtained.

[0072] Weigh 1 mg of the AgCl / CuO catalyst obtained in step 4 above, disperse it in 0.1 mL of a mixed solution containing isopropanol and naphthol with a volume ratio of 9:1, and ultrasonically disperse it for 30 min to obtain a uniformly dispersed mixed solution. Use a pipette with a measuring range of 10 μL to take 4 μL of the uniformly dispersed mixed solution and drop-coat it on the glassy carbon electrode with an area of 3 x 3 mm² in two times. The glassy carbon electrode coated with the catalyst is directly used as the working electrode after drying, with an Ag / AgCl electrode as the reference electrode and a 1 x 1 cm² platinum plate electrode as the counter electrode to form a three-electrode system, and electrocatalytic water splitting for ethylene production is tested in an electrolyte of 0.5 M KHCO3. At the beginning of the test, the catalyst needs to be reconstructed at a potential of -1.1 V (vs. RHE) for 30 min to obtain an Ag / Cu catalyst. Linear sweep voltammetry (LSV) is used in the test to explore the electrocatalytic activity of the catalyst, and the stability of the catalyst is illustrated by testing the change of current with time at a fixed potential through chronopotentiometry.

[0073] Test Example 2:

[0074] In this test example, electrocatalytic water splitting for ethylene production is tested. The implementation steps are the same as those in Test Example 1, except that the AgCl / CuO nanocatalyst prepared in Example 2 is used for testing, and the test results are close to those obtained in Test Example 1.

[0075] Test Example 3:

[0076] In this test example, electrocatalytic water splitting for ethylene production is tested. The implementation steps are the same as those in Test Example 1, except that the AgCl / CuO nanocatalyst prepared in Example 3 is used for testing, and the test results are close to those obtained in Test Example 1.

[0077] Test Example 4:

[0078] In this test example, electrocatalytic water splitting for ethylene production is tested. The implementation steps are the same as those in Test Example 1, except that the AgCl / CuO nanocatalyst prepared in Example 4 is used for testing, and the test results are close to those obtained in Test Example 1.

[0079] Test Example 5:

[0080] This test example conducts a test on the catalytic water splitting to produce ethylene. The implementation steps are the same as those in Test Example 1, except that the reconstruction potential in the test steps is -0.8 V (vs. RHE), and other conditions remain unchanged. The test results obtained are close to those obtained in Test Example 1.

[0081] The test results obtained in the above Test Examples 1 - 5 are: the Faraday efficiency of ethylene (i.e., the ratio between the actually produced ethylene and the theoretically produced ethylene during the electrochemical reduction of carbon dioxide).

[0082] Adopting the above technical solution, at room temperature, using copper sources (copper(II) chloride dihydrate, copper(II) nitrate trihydrate) and silver metal salts as raw materials, deionized water as the solvent, and adding an alkali source (such as potassium hydroxide, sodium hydroxide, ethylenediamine), AgCl / Cu(OH)₂ nanomaterials are synthesized, and then AgCl / CuO nanocatalysts are obtained through calcination. This preparation process is simple and novel, with mild reaction conditions and short time consumption. The prepared composite catalyst has unique morphological characteristics; it can efficiently and rapidly reduce carbon dioxide in the atmosphere to organic chemical raw materials, such as carbon monoxide, methane, and ethylene, and shows excellent Faraday efficiency in the production of ethylene. Therefore, the synthesis method of this AgCl / CuO catalyst has important application value in large-scale industrial practical applications.

[0083] In summary, the present invention provides a synthesis method of a special-shaped AgCl / CuO mixed catalyst for preparing ethylene. The catalyst has low raw material prices, a simple preparation process, and mild reaction conditions. The prepared catalyst is applied to the electrochemical production of ethylene test in a neutral electrolyte and shows excellent catalytic activity and stability, with an ethylene Faraday efficiency as high as 72%.

[0084] The further explanations regarding the drawings in the specification are as follows:

[0085] Figure 3 The transmission electron microscope (STEM - EDS) image corresponding to the 25% AgCl / Cu(OH)₂ nanomaterial in terms of molar ratio shows that AgCl nanoparticles with a size of about 10 nm are uniformly loaded on the Cu(OH)₂ porous nanobelts.

[0086] Figure 4 The transmission electron microscope (STEM - EDS) comparison image corresponding to Cu(OH)₂ powder and 25% AgCl / CuO powder in terms of molar ratio; among them: Figure 4 The left figure corresponds to the transmission electron microscope (STEM - EDS) image of Cu(OH)₂ powder, Figure 4The right figure corresponds to the transmission electron microscope (STEM-EDS) image of 25% AgCl / CuO in molar ratio; it can be seen from the comparison that there are mesoporous structures on the CuO nanobelts. As can be seen from the right figure, AgCl nanoparticles with a size of about 10 nm are uniformly loaded on the porous CuO nanobelts.

[0087] Figure 5 The transmission electron microscope (STEM-EDS) image of Ag / Cu powder after reconstructing for 30 min at -1.1 V (vs. RHE) for 25% AgCl / CuO shows that after the electrocatalytic carbon dioxide reaction, uniform Ag / Cu nanoparticles with a size of about 10 nm are formed.

[0088] Figure 6 This is the HRTEM image of the 25% AgCl / CuO powder according to the present invention. It can be seen that there are high grain boundary densities and the interlaced (200) crystal planes of AgCl and (111) and (002) crystal planes of CuO, indicating that AgCl is well loaded on the CuO nanobelts.

[0089] Figure 7 The XRD patterns corresponding to the AgCl / CuO catalysts with different molar ratios show that a series of AgCl / CuO catalysts with molar ratios of 1%, 10%, 25%, 50%, and 100% (denoted as sample 1, sample 2, sample 3, sample 4, and sample 5) are successfully prepared. It is found that as the AgCl loading increases, the diffraction peak intensity of AgCl gradually increases. The AgCl / CuO catalysts with molar ratios of 1%, 10%, 25%, 50%, and 100% are denoted as sample 1, sample 2, sample 3, sample 4, and sample 5 respectively, corresponding to Figure 5 AgCl / CuO-1, AgCl / CuO-2, AgCl / CuO-3, AgCl / CuO-4, and AgCl / CuO-5 in

[0090] Figure 8 The XRD patterns corresponding to 25% AgCl / CuO and its precursor. Calcining in air atmosphere at 250 °C for 10 min can effectively convert 25% AgCl / Cu(OH)2 into 25% AgCl / CuO.

[0091] Figure 9 The linear sweep voltammetry (LSV) curves corresponding to the AgCl / CuO powders with molar ratios of 1%, 10%, 25%, 50%, and 100% (denoted as sample 1, sample 2, sample 3, sample 4, and sample 5) show that at a potential of -1 V (vs. RHE), compared with the other 4 samples, the current density of 25% AgCl / CuO (sample 3) is the largest, reaching 140 mA / cm 2。

[0092] Figure 10 Corresponding to the linear sweep voltammetry (LSV) curves of 25% AgCl / CuO powders synthesized using different copper sources (copper(II) chloride dihydrate and copper(II) nitrate trihydrate), it can be seen that the 25% AgCl / CuO catalyst prepared with copper(II) chloride dihydrate as the copper source during the synthesis process has the largest current density, which can reach 140 mA / cm 2 。

[0093] Figure 11 Corresponding to the electrocatalytic carbon dioxide reduction performance diagrams of 1%, 10%, 25%, 50%, and 100% molar ratio AgCl / CuO powder catalysts (denoted as Sample 1, Sample 2, Sample 3, Sample 4, and Sample 5) at -1 V (vs. RHE) potential, it can be seen that the main reduction products are hydrogen, carbon monoxide, ethylene, and methane. Compared with the other 4 samples, 25% AgCl / CuO (Sample 3) has the highest ethylene Faraday efficiency (72%) and the lowest hydrogen Faraday efficiency (18%). The performance results show that the 25% AgCl / CuO (Sample 3) powder catalyst has the best activity for electroreduction of carbon dioxide to ethylene and can effectively inhibit the hydrogen evolution side reaction.

[0094] Figure 12 Corresponding to the electrocatalytic carbon dioxide performance diagrams of 25% AgCl / CuO powder at different potentials, it can be seen that the main reduction products are hydrogen, carbon monoxide, ethylene, and methane. Compared with other potentials, at -1 V (vs. RHE) potential, it has the highest ethylene Faraday efficiency (72%) and the lowest hydrogen Faraday efficiency (18%). The performance results show that at -1 V (vs. RHE) potential, it has the best activity for electroreduction of carbon dioxide to ethylene and can effectively inhibit the hydrogen evolution side reaction.

[0095] Figure 13 Corresponding to the infrared spectrum (FT-IR) of 25% AgCl / CuO powder, it can be seen that the characteristic peaks at wavenumbers 3447.79 and 1082.55 correspond to the Ag-Cl vibration mode, and the characteristic peaks at wavenumbers 1618.16 and 478.2 correspond to the Cu-O vibration mode.

[0096] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention fall within the scope of protection required by the present invention.

Claims

1. Application of an AgCl / CuO nanocatalyst, characterized in that, When applying it to the electrocatalytic reduction of CO₂ to ethylene, the preparation method of the AgCl / CuO nanocatalyst includes the following steps: using a copper source and a silver metal salt as raw materials, deionized water as a solvent, adding an alkali source, synthesizing an AgCl / Cu(OH)₂ nanomaterial, and then obtaining the AgCl / CuO nanocatalyst through calcination; The specific operations are as follows: Step 1: Dissolve 0.2 mmol of copper chloride dihydrate in 25 mL of deionized water and stir evenly, then add 2 mL of 16 M alkali source to the previous solution and stir well for 30 minutes to obtain a Cu(OH)₂ aqueous solution; Step 2: Dissolve 0.085 g of silver nitrate solid in 10 mL of deionized water to obtain a 0.05 M silver nitrate aqueous solution; Step 3: Add 1 mL of 0.05 M AgNO₃ solution to the Cu(OH)₂ solution prepared in Step 1. After reacting for 10 minutes, wash with deionized water, ethanol, and cyclohexane in sequence, then ultrasonically disperse evenly in 5 mL of cyclohexane, and perform freeze-drying overnight to obtain an AgCl / Cu(OH)₂ precursor; Step 4: Calcinate the obtained AgCl / Cu(OH)₂ precursor at 250 °C for 10 min to obtain the AgCl / CuO nanocatalyst.

2. The application of an AgCl / CuO nanocatalyst according to claim 1, characterized in that, The alkali source is taken from any one of potassium hydroxide, sodium hydroxide, and ethylenediamine.

3. The application of an AgCl / CuO nanocatalyst according to claim 1, characterized in that, In the AgCl / CuO nanocatalyst, the molar ratio of AgCl to CuO is 1:4, that is, 25% AgCl / CuO.

4. The application of an AgCl / CuO nanocatalyst as described in claim 1, wherein, In Step 3, the washing method is to wash with deionized water, ethanol, and cyclohexane in sequence. After each washing, centrifuge to collect the solid, and finally store the solid in cyclohexane for freeze-drying.

5. The application of an AgCl / CuO nanocatalyst according to claim 1, characterized in that, In Step 4, the calcination operation is carried out in air, and the obtained AgCl / CuO nanocatalyst is stored under normal temperature and dry conditions.

6. The application of an AgCl / CuO nanocatalyst as described in claim 1, wherein In the AgCl / CuO nanocatalyst: CuO exists in the form of nanobelts with a porous structure and rich in high grain boundary density, and AgCl nanoparticles are evenly distributed on the CuO nanobelt support to expose more carbon dioxide reduction active sites.

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