Cu-Ag-Ni multi-site electro-catalytic material as well as preparation method and application thereof

Abstract

The invention relates to a Cu-Ag-Ni multi-site electro-catalytic material and a preparation method and application thereof, and relates to the field of the preparation method and application of the Cu-Ag-Ni multi-site electro-catalytic material. According to the method, the Cu-Ag-Ni multi-site electro-catalytic material is prepared by a sodium borohydride co-reduction method, and the method comprises the following specific steps: dissolving copper salt, silver salt and nickel salt in a molar ratio of 40: 1: 1 in deionized water to form a uniform solution; injecting the solution into a 1M sodium borohydride solution, and stirring in an ice bath for 2 hours; and after the reaction, centrifuging to obtain a precipitate, alternately washing with ethanol and water, and carrying out vacuum drying at room temperature for 12 hours to obtain the Cu-Ag-Ni electro-catalytic material. The electrocatalytic material shows excellent performance in the aspect of electrocatalytic conversion of carbon dioxide at room temperature. In addition, the preparation method of the Cu-Ag-Ni multi-site electro-catalytic material has the remarkable advantages that the reaction condition is mild, the energy consumption is low, the technological process is simple and convenient, the cost benefit is high, and the preparation method is very suitable for large-scale industrial production and application.

Description

Technical Field

[0001] The present invention belongs to the field of catalyst preparation, and specifically relates to a Cu-Ag-Ni multi-site electrocatalytic material and a preparation method and application thereof, and in particular relates to a preparation method of a Cu-Ag-Ni multi-site electrocatalytic material and an application thereof in preparing multi-carbon products by electrocatalytic carbon dioxide reduction. Background Art

[0002] Carbon dioxide (CO2), as a greenhouse gas, has a profound impact on the global climate, but it is also regarded as a rich source of carbon. Through electrocatalytic reduction technology, CO2 can be converted into high-value chemicals and fuels such as methanol, ethanol, and ethylene, which are widely used in the chemical, energy, and transportation fields, and are of great significance to the sustainable development of society. In the electrocatalytic process, metal catalysts play a core role, and different metals have a significant effect on the reduction path and product distribution of CO2. For example, copper (Cu) and nickel (Ni) can catalyze the generation of multi-carbon products, while gold, silver (Ag) and lead (Pb) mainly generate single-carbon products such as carbon monoxide (CO) or formic acid (HCOOH). However, this field still faces many challenges, such as the complex process of multi-carbon product generation, the need for high energy input and precise control of reaction conditions, and the difficulty of metal catalysts to simultaneously meet the requirements of high activity and high selectivity. Stability and regeneration are also key constraints for industrial applications.

[0003] In order to improve the performance of metal catalysts in the electrocatalytic reduction of CO2 to prepare multi-carbon products, researchers have conducted a lot of exploration. By regulating the surface structure and composition of metal catalysts, such as constructing nanostructures, alloying or surface modification, their adsorption and activation capabilities for CO2 can be optimized, and the catalytic activity and selectivity can be improved. At the same time, optimizing the electrocatalytic reaction conditions, such as electrolyte type, concentration, temperature and pressure, can also further regulate the reaction path and product distribution of CO2 reduction. In addition, the regeneration and stability of metal catalysts are current research hotspots. By designing a reasonable catalyst structure and preparation process, improving the anti-poisoning ability and durability of the catalyst is the key to extending its service life and reducing production costs. Developing renewable metal catalysts or using waste metals to prepare catalysts is also an important way to achieve sustainable development. In the future, metal catalysts will play a more important role in promoting social sustainable development, but in-depth research is still needed in catalyst design, preparation process and reaction condition optimization. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a Cu-Ag-Ni multi-site electrocatalytic material. The method is a simple sodium borohydride reduction method and can prepare the Cu-Ag-Ni multi-site electrocatalytic material on a large scale.

[0005] Another object of the present invention is to provide a Cu-Ag-Ni multi-site electrocatalytic material product and application.

[0006] The specific technical scheme for achieving the purpose of the present invention is: using different metal salts as raw materials, and preparing Cu-Ag-Ni multi-site electrocatalytic material by sodium borohydride reduction method, including the following steps:

[0007] Step 1: Preparation of copper salt solution:

[0008] Dissolve 3 mM copper salt, 0.75 mM silver salt, and 0.75 mM nickel salt in deionized water and stir for 30 min to completely dissolve;

[0009] Step 2: Preparation of Cu-Ag-Ni multi-site electrocatalytic materials:

[0010] The prepared solution was injected into a 1M sodium borohydride solution and stirred for 2 hours in an ice bath. After the reaction, the precipitate was obtained by centrifugation, washed alternately with ethanol and water for several times, and dried at room temperature under vacuum for 12 hours to obtain a Cu-Ag-Ni multi-site electrocatalytic material.

[0011] Furthermore, in the method for preparing the Cu-Ag-Ni multi-site electrocatalytic material, the metal salt solution in step 1 can be any one of nitrate, acetate, and gluconate metal salt solutions.

[0012] Furthermore, in the method for preparing the Cu-Ag-Ni multi-site electrocatalytic material, the reducing agent in the second step can be any one of sodium borohydride, potassium borohydride, lithium borohydride, zinc borohydride, etc., and the amount of the reducing agent added is excessive.

[0013] The Cu-Ag-Ni multi-site electrocatalytic material was prepared according to the above preparation method.

[0014] The present invention also provides the use of Cu-Ag-Ni multi-site electrocatalytic material in preparing multi-carbon products by electrocatalytic reduction of carbon dioxide.

[0015] One of the purposes of the present invention is to provide the application of the Cu-Ag-Ni multi-site electrocatalytic material prepared according to the method provided by the present invention in the electrocatalytic reduction of carbon dioxide, especially in the preparation of multi-carbon products by electrocatalytic reduction of carbon dioxide.

[0016] The advantages of the method for preparing the Cu-Ag-Ni multi-site electrocatalytic material provided by the present invention are:

[0017] The present invention provides a new method for preparing Cu-Ag-Ni multi-site electrocatalytic material, which uses a widely available and cost-effective mixed solution of copper salt, silver salt and nickel salt as the starting material.

[0018] Using sodium borohydride reduction technology, the entire preparation process is not only simple and fast, but also highly scalable, creating favorable conditions for large-scale industrial production.

[0019] The obtained Cu-Ag-Ni multi-site electrocatalytic material exhibits excellent electrocatalytic activity and strong structural stability, which give it significant advantages in electrochemical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a SEM image of the Cu-Ag-Ni material prepared in Example 1;

[0021] Figure 2 This is a graph showing the electrocatalytic carbon dioxide reduction performance of the Cu-Ag-Ni material prepared in Example 1;

[0022] Figure 3 This is a diagram of the electrolytic stability of the Cu-Ag-Ni material prepared in Example 1 for electrocatalytic carbon dioxide reduction. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments, but the present invention is not limited to the following embodiments.

[0024] Example 1

[0025] Dissolve 3mM copper nitrate, 0.75mM silver nitrate and 0.75mM nickel nitrate in 25mL deionized water and stir continuously for 30min at room temperature to ensure that all metal salts are completely dissolved to form a uniform solution system. Inject the prepared solution into 15mL 1M sodium borohydride solution and stir for 2h under ice bath conditions. After the reaction, obtain the precipitate by centrifugation, wash it alternately with ethanol and water several times, and dry it under vacuum conditions at room temperature for 12h to obtain the Cu-Ag-Ni multi-site electrocatalytic material.

[0026] Figure 1 This is the SEM image of the Cu-Ag-Ni multi-site electrocatalytic material obtained in Example 1. Figure 1 It can be seen that the Cu-Ag-Ni multi-site electrocatalytic material presents a network structure composed of interconnected nanoparticles, and the size of these nanoparticles is about 30 to 40 nanometers.

[0027] Example 2

[0028] Dissolve 3mM copper acetate, 0.75mM silver acetate and 0.75mM nickel acetate in 25mL deionized water and stir continuously for 30min at room temperature to ensure that all metal salts are completely dissolved to form a uniform solution system. Inject the prepared solution into 15mL 1M sodium borohydride solution and stir for 2h under ice bath conditions. After the reaction, obtain the precipitate by centrifugation, wash it alternately with ethanol and water several times, and dry it under vacuum conditions at room temperature for 12h to obtain the Cu-Ag-Ni multi-site electrocatalytic material.

[0029] Example 3

[0030] Dissolve 3mM copper nitrate, 0.75mM silver nitrate and 0.75mM nickel nitrate in 25mL deionized water and stir continuously for 30min at room temperature to ensure that all metal salts are completely dissolved to form a uniform solution system. Inject the prepared solution into 15mL 1M potassium borohydride solution and stir for 2h under ice bath conditions. After the reaction, obtain the precipitate by centrifugation, wash it alternately with ethanol and water several times, and dry it under vacuum conditions at room temperature for 12h to obtain the Cu-Ag-Ni multi-site electrocatalytic material.

[0031] Example 4

[0032] The corresponding electrochemical test experiments were completed on the Shanghai Chenhua electrochemical workstation (CHI 660E). The electrolysis test was carried out in a flow-type electrolytic cell, using a three-electrode system, including a working electrode (Cu-Ag-Ni multi-site electrocatalytic material), nickel foam as a counter electrode, and Ag / AgCl as a reference electrode. During the electrolysis process, the cathode / anode chambers were separated by an anion exchange membrane, and the electrolytes in the cathode chamber and the anode chamber were both 1M KOH electrolytes. In the constant potential mode, each potential was electrolyzed for 1 h, and the gas and liquid products were collected.

[0033] The components of the gaseous and liquid products were detected and analyzed using a gas chromatograph (Agilent 8890) and a nuclear magnetic resonance spectrometer (1H NMR, Bruker Ascend 500 MHz). Figure 2 As shown in Figure 2, the Faradaic efficiency of the Cu-Ag-Ni multi-site electrocatalytic material for multi-carbon products at an electrolysis potential of −1.38 V vs. RHE is 93.2% and the current density is 818.1 mA cm -2 .

[0034] We further evaluated the stability of the Cu-Ag-Ni multi-site electrocatalytic material at an electrolysis potential of -1.38 V vs. RHE. Figure 3 As shown, during 9 hours of continuous operation, the system maintained a stable current density and the Faradaic efficiency (FE) of the multi-carbon products remained above 90%.

[0035] The applicant declares that the specific embodiments of the present invention have been described in detail above, but this is only presented as an example, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and alternatives to the present invention are within the scope of protection of the present invention. Therefore, without violating the core concept and protection scope of the present invention, all equivalent changes and adjustments are also within the scope of the present invention.

Claims

1. A method for preparing a Cu-Ag-Ni multi-site electrocatalytic material, characterized in that: This preparation method can achieve large-scale preparation of uniform Cu-Ag-Ni multi-site electrocatalytic materials through a simple sodium borohydride co-reduction method.

2. The method for preparing a Cu-Ag-Ni multi-site electrocatalytic material according to claim 1, characterized in that: The specific steps include: Step 1: Preparation of metal salt solution: Dissolve 3 mM copper salt, 0.75 mM silver salt, and 0.75 mM nickel salt in deionized water and stir for 30 min to completely dissolve; Step 2: Preparation of Cu-Ag-Ni multi-site electrocatalytic materials: The solution prepared in step 1 was injected into a 1M sodium borohydride solution (as a reducing agent) and stirred for 2 hours in an ice bath. After the reaction, the precipitate was obtained by centrifugation, and washed alternately with ethanol and water for 6 times, and dried at room temperature under vacuum for 12 hours to obtain a Cu-Ag-Ni multi-site electrocatalytic material.

3. The method for preparing the Cu-Ag-Ni multi-site electrocatalytic material according to claim 2, characterized in that: The metal salt solution in step 1 can be any one of nitrate and acetate metal salt solutions.

4. The method for preparing the Cu-Ag-Ni multi-site electrocatalytic material according to claim 2, characterized in that: The reducing agent in step 2 can be any one of sodium borohydride, potassium borohydride, lithium borohydride, and zinc borohydride.

5. The Cu-Ag-Ni multi-site electrocatalytic material prepared by the preparation method according to any one of claims 1 to 4.

6. Use of the Cu-Ag-Ni multi-site electrocatalytic material according to claim 5 in preparing multi-carbon products by electrocatalytic reduction of carbon dioxide.

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