Electrocatalyst based on cationic conductive modification layer and preparation method and application thereof

Abstract

The invention discloses an electrocatalyst based on a cationic conductive modification layer and a preparation method and application thereof, and relates to the technical field of electrocatalyst preparation. The preparation method comprises the following steps: doping polyaniline with 2-aminobenzene sulfonic acid to prepare a cation conductive modification material (ABSA-PANI), and combining the cation conductive modification material with a Cu-based catalyst to prepare the electrocatalyst based on the cation conductive modification layer. According to the prepared electrocatalyst, microenvironment regulation and control are combined with intrinsic catalytic activity enhancement, so that the kinetic process of CO2RR multi-proton coupling electron transfer is accelerated, and the performance of CO2RR under the acidic condition is further improved. Specifically, under the conditions of an acidic medium (pH < = 1) and high current density (600mA / cm < 2 >), the highest Faraday efficiency of the multi-carbon product can reach 81%, and the corresponding partial current density is 486mA / cm < 2 >.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst preparation, and in particular to an electrocatalyst based on a cationic conductive modified layer, and a preparation method and application thereof. Background Art

[0002] Electrocatalytic CO2 reduction reaction (CO2RR) refers to the use of renewable electricity resources to convert carbon dioxide (CO2) into valuable chemicals and fuels, which is of great significance to promoting resource recycling and promoting sustainable development. In the CO2RR process, the electrolyte includes acidic and alkaline media. Among them, in alkaline media, CO2 will react with hydroxides in the electrolyte to form carbonates. The deposition of carbonates will greatly limit the utilization efficiency of CO2 (SPCE C2+ <25%), and cause serious energy loss. In acidic medium, although the H + It can effectively alleviate the formation and deposition of hydrochloride, but the abundant proton source in the acidic medium will lead to competitive HER. Competitive HER is more likely to occur than CO2RR. The occurrence of competitive HER will aggravate the degree of catalyst structural reconstruction and degradation, thereby limiting the selectivity and activity of CO2RR.

[0003] Catalysts are the main factor that determines the selectivity, stability and activity of CO2RR. In order to improve the activity and selectivity of CO2RR in acidic environments, catalysts are often adjusted and modified, such as the introduction of alkali metal cations, hydrophobic ligand modification, organic modification and catalyst structure regulation. Among them, organic molecule modification is a widely used measure. Its principle is to use organic molecules to regulate the microenvironment of the metal surface. Organic molecules can give catalysts unique electronic and steric effects, provide additional adsorption sites for catalytic reactions, and introduce special functional groups into organic molecules to regulate the stability of reaction intermediates. However, the electron transfer ability of most organic molecules is low, which greatly limits their application in CO2RR.

[0004] In the prior art, CN118345415A discloses a polyaniline-supported copper catalyst that can be used for electrocatalytic CO2 reduction reaction. Its preparation method is as follows: dissolving aniline in an acidic solution, adding ammonium persulfate to react and obtain polyaniline; dispersing polyaniline in water, adding the dispersion to a copper ion salt and a nitrogen-containing alkaline solution to react to form a complex, and then calcining at high temperature to reduce the copper ions to metallic copper to obtain a polyaniline-supported copper catalyst. Since the polyaniline is not doped and modified in the above patent, the electron transfer ability of the polyaniline is still low, and it is unable to quickly and effectively transfer electrons to the reaction substrate, thereby limiting the efficiency of CO2RR. In addition, using undoped and modified polyaniline-supported copper as a catalyst makes it difficult to create a local high pH microenvironment, so that HER still dominates, thereby reducing the selectivity and activity of CO2RR, and it is difficult to efficiently convert CO2 into the target product.

[0005] Therefore, it is necessary to use polyaniline, an organic molecule, as a matrix material and to dope and modify it to prepare an electrocatalyst in order to improve the electron transfer rate of polyaniline and thus improve the selectivity of the electrocatalyst in catalyzing CO2 reduction in acidic media. Summary of the Invention

[0006] In response to the above-mentioned prior art, the present invention aims to provide an electrocatalyst based on a cationic conductive modified layer, as well as its preparation method and application. The present invention uses 2-aminobenzenesulfonic acid to dope polyaniline to prepare a cationic conductive modified material (ABSA-PANI), which is then combined with a copper-based catalyst to prepare an electrocatalyst based on a cationic conductive modified layer. The electrocatalyst prepared by the present invention accelerates the kinetic process of multi-proton coupled electron transfer in CO2RR by combining microenvironmental regulation with enhanced intrinsic catalytic activity, thereby improving the performance of CO2RR under acidic conditions.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] The first aspect of the present invention provides a method for preparing an electrocatalyst based on a cationic conductive modified layer, comprising the following steps:

[0009] (1) 2-aminobenzenesulfonic acid and aniline are mixed and ground to obtain a mixture; ammonium persulfate is added to the mixture to react, and after the reaction is completed, the mixture is washed and dried to obtain a cationic conductive modified material, which is recorded as ABSA-PANI;

[0010] (2) A cationic conductive modifying material, isopropyl alcohol, and a binder are mixed and ultrasonically treated to obtain a catalyst ink, and the catalyst ink is sprayed onto a Cu-based electrocatalyst to obtain an electrocatalyst based on a cationic conductive modifying layer.

[0011] Preferably, in step (1), the molar ratio of aniline, ammonium persulfate and 2-aminobenzenesulfonic acid is 1:(0.5-1):(0.5-1).

[0012] Preferably, in step (1), the grinding time is 5-15 min.

[0013] Preferably, in step (1), the reaction time is 20-40 min.

[0014] Preferably, in step (1), during the washing process, ultrapure water and ethanol are used for washing 2-3 times.

[0015] Preferably, in step (1), the drying method is vacuum drying, the drying time is 11-13 hours, and the drying temperature is 50-70°C.

[0016] Preferably, in step (2), the Cu-based electrocatalyst is prepared by the following method:

[0017] Copper nanoparticles, isopropyl alcohol and perfluorosulfonic acid resin are mixed and ultrasonically treated, and the ultrasonically treated system is sprayed onto a GDE electrode to form a copper nanoparticle catalyst layer, thereby obtaining a Cu-based electrocatalyst.

[0018] Furthermore, in the Cu-based electrocatalyst, the thickness of the copper nanoparticle catalyst layer is 5-7 μm, and the loading amount of the copper nanoparticles is 0.4-0.6 mg / cm 2 ; The ultrasonic treatment time is 20-40 min; the addition ratio of copper nanoparticles, isopropanol and perfluorosulfonic acid resin is (15-20) mg:2 mL:100 μL.

[0019] Preferably, in step (2), the loading amount of the cationic conductive modifying material in the electrocatalyst based on the cationic conductive modifying layer is 0.4-0.6 mg / cm 2 .

[0020] Preferably, in step (2), the ultrasonic treatment time is 20-40 min.

[0021] Preferably, in step (2), the added amount ratio of the cationic conductive modifying material, isopropyl alcohol and adhesive is (10-20) mg:2 mL:60 μL; wherein the adhesive is perfluorosulfonic acid resin.

[0022] The second aspect of the present invention provides an electrocatalyst based on a cationic conductive modified layer prepared by the above preparation method.

[0023] The third aspect of the present invention provides the use of the above-mentioned electrocatalyst based on the cationic conductive modified layer in electrocatalytic CO2 reduction.

[0024] Preferably, an acidic electrolyte is used in the electrocatalytic CO2 reduction process; in the acidic electrolyte, the concentration of KCl is 0.8-1.2M, and the concentration of H2SO4 is 0.04-0.06M.

[0025] Beneficial effects of the present invention:

[0026] 1. This invention uses 2-aminobenzenesulfonic acid to dope polyaniline to produce a cationic conductive modified material (ABSA-PANI). This cationically conductive modified material is then combined with a copper-based catalyst to produce an electrocatalyst based on a cationic conductive modified layer. This electrocatalyst combines microenvironmental manipulation with enhanced intrinsic catalytic activity to accelerate the kinetics of multi-proton coupled electron transfer in CO₂RR, thereby improving CO₂RR performance under acidic conditions.

[0027] Specifically, in acidic medium (pH ≤ 1) and high current density (600 mA / cm 2 ), the Faradaic efficiency of multi-carbon products can reach up to 81%, corresponding to a partial current density of 486 mA cm -2 At the same time, it has a single-pass CO2 conversion efficiency of up to 52.8% and a cathode energy efficiency of 27%.

[0028] 2. The present invention uses 2-aminobenzenesulfonic acid to dope polyaniline to prepare ABSA-PAN. On the one hand, when 2-aminobenzenesulfonic acid is doped with polyaniline, the charge on the polyaniline molecular chain is delocalized, and the electron cloud is rearranged to form a conjugated structure. This structural change significantly reduces the interfacial electron transfer resistance and improves the electron conductivity. Compared with undoped polyaniline, the charge transfer resistance of ABSA-PAN is significantly reduced, which can more efficiently promote carrier transfer in the electrocatalytic process, provide more favorable electron transport conditions for CO2RR, and improve reaction kinetics. On the other hand, the imine group of the doped polyaniline is protonated to form a high-density cationic site on the molecular skeleton. These cationic sites can enrich alkali metal cations (such as K + ), and can also inhibit H + mass transfer and limit the in situ generated OH - Through these effects, a stable local high pH microenvironment is successfully constructed. In this microenvironment, HER is effectively inhibited because the high pH environment is not conducive to H +Electrons are obtained to generate H2; at the same time, the enhanced alkalinity facilitates the adsorption and activation of CO2, promoting its conversion to multi-carbon products and improving the selectivity and activity of CO2RR. Finally, 2-aminobenzenesulfonic acid-doped polyaniline acts as a cationic conductive modification layer, providing protection for the copper catalyst. It can hinder the penetration of electrolyte into copper nanoparticles and reduce direct contact between acidic substances and copper, thereby effectively delaying the degradation and reconstruction of copper nanoparticles under acidic conditions and improving the stability of the electrocatalyst. Experiments show that the doped and modified Cu / ABSA-PANI catalyst can maintain its original morphology during the reaction, while the surface of the unmodified copper catalyst undergoes significant changes, demonstrating the important role of doping in improving catalyst stability.

[0029] 3. The present invention adopts ABSA-PANI as a cationic conductive modification layer and combines it with copper nanoparticles to prepare an electrocatalyst that achieves high selectivity for C without high voltage. 2+ The formation of products, in order to improve the conversion of CO2 to C under acidic conditions 2+ Product conversion provides a route with high energy efficiency and good operational stability.

[0030] The electrocatalyst produced by this invention maintains excellent CO2 electroreduction performance even at low alkali metal cation concentrations, low CO2 concentrations, and low applied potentials. This opens up the possibility of practical industrial applications of CO2 electroreduction reactions, particularly in conjunction with the capture and utilization of CO2 in flue gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 : Scanning electron micrographs of the electrocatalyst based on the cation conductive modified layer, the cation conductive modified powder, and the copper nanoparticle catalyst layer prepared by the present invention; wherein, (a) is a scanning electron micrograph of the electrocatalyst based on the cation conductive modified layer; (b) is a scanning electron micrograph of the cation conductive modified powder; (c) is a scanning electron micrograph of the copper nanoparticle catalyst layer''

[0032] Figure 2 : Fourier transform infrared spectra of the electrocatalysts prepared in Example 1 and Comparative Examples 1-4;

[0033] Figure 3 : N1s X-ray photoelectron spectra of the electrocatalysts prepared in Example 1 and Comparative Example 1;

[0034] Figure 4 : In Experiment 2, each electrocatalyst was 2 The Faradaic efficiency and C at a constant current density 2+ Faraday efficiency diagram;

[0035] Figure 5: Product selectivity diagram of each electrocatalyst at different current densities in Experimental Example 2;

[0036] Figure 6 : In Experimental Example 2, K is adsorbed on the surface of each electrocatalyst. + Concentration graph. DETAILED DESCRIPTION

[0037] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0038] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0039] The experimental materials used in the examples of the present invention are all conventional experimental materials in the art and can be purchased through commercial channels.

[0040] Example 1: Preparation of electrocatalyst based on cation conductive modified layer

[0041] (1) 0.012 mol of 2-aminobenzenesulfonic acid and 0.01 mol of aniline were mixed to obtain a mixture; the mixture was placed in a mortar and ground for 10 min until the mixture formed a uniform white paste, and then 0.01 mol of ammonium persulfate was added and ground for 30 min to perform a coupling reaction to obtain a polymer; the polymer was washed three times with ultrapure water and ethanol, and then vacuum-dried at 60°C for 12 h to obtain a cationic conductive modified powder, which was designated as ABSA-PANI;

[0042] (2) 18 mg of copper nanoparticles, 2 mL of isopropanol, and 100 μL of perfluorosulfonic acid resin were mixed and ultrasonicated for 30 min. The mixture was sprayed onto a 3 × 3 cm GDE (gas diffusion) electrode using a spray gun to prepare a Cu-based electrocatalyst, denoted as Cu.

[0043] The Cu-based electrocatalyst has a copper nanoparticle loading of 0.5 mg / cm 2 ;

[0044] (3) 18 mg of ABSA-PANI powder, 2 mL of isopropanol, and 60 μL of perfluorosulfonic acid resin were mixed and ultrasonicated for 30 min to obtain a catalyst ink. The catalyst ink was sprayed onto a Cu-based electrocatalyst to obtain an electrocatalyst based on a cationic conductive modified layer, which was recorded as Cu / ABSA-PANI.

[0045] In the electrocatalyst based on the cationic conductive modified layer, the loading amount of ABSA-PANI is 0.5 mg / cm 2 .

[0046] Comparative Example 1:

[0047] The difference between Comparative Example 1 and Example 1 is that 2-aminobenzenesulfonic acid was not added during the preparation of the electrocatalyst. The specific preparation steps are as follows:

[0048] (1) 0.012 mol of 2-aminobenzenesulfonic acid was placed in a mortar and ground for 10 min, and then 0.01 mol of ammonium persulfate was added and ground for 30 min to perform a coupling reaction to obtain a polymer. The polymer was washed three times with ultrapure water and ethanol, and then vacuum-dried at 60°C for 12 h to obtain PANI powder.

[0049] (2) 15 mg of PANI powder, 2 mL of isopropanol, and 60 μL of perfluorosulfonic acid resin were mixed and ultrasonicated for 30 min to obtain a catalyst ink. The catalyst ink was sprayed onto the Cu-based electrocatalyst prepared in Example 1 to obtain an electrocatalyst, which was recorded as Cu / PANI.

[0050] The loading amount of PANI in the electrocatalyst is 0.5 mg / cm 2 .

[0051] Comparative Example 2:

[0052] The difference between this comparative example 1 and Example 1 is that dodecylbenzenesulfonic acid (DBSA) is used instead of 2-aminobenzenesulfonic acid. The specific steps are:

[0053] (1) 0.012 mol of dodecylbenzenesulfonic acid and 0.01 mol of aniline were mixed to obtain a mixture; the mixture was placed in a mortar and ground for 10 minutes until the mixture formed a uniform white paste; then 0.01 mol of ammonium persulfate was added and ground for 30 minutes to perform a coupling reaction to obtain a polymer; the polymer was washed three times with ultrapure water and ethanol, and then vacuum dried at 60°C for 12 hours to obtain DBSA-PANI powder;

[0054] (2) 15 mg of DBSA-PANI powder, 2 mL of isopropyl alcohol, and 60 μL of perfluorosulfonic acid resin were mixed and ultrasonicated for 30 min to obtain a catalyst ink. The catalyst ink was sprayed onto the Cu-based electrocatalyst prepared in Example 1 to obtain an electrocatalyst. The loading amount of DBSA-PANI in the electrocatalyst was 0.5 mg / cm 2 .

[0055] Comparative Example 3:

[0056] The difference between this comparative example and Example 1 is that sulfuric acid is used instead of 2-aminobenzenesulfonic acid. The specific steps are as follows:

[0057] (1) 0.012 mol of sulfuric acid and 0.01 mol of aniline were mixed to obtain a mixture; the mixture was placed in a mortar and ground for 10 minutes until the mixture formed a uniform white paste, and then 0.01 mol of ammonium persulfate was added and ground for 30 minutes to perform a coupling reaction to obtain a polymer; the polymer was washed three times with ultrapure water and ethanol, and then vacuum dried at 60°C for 12 hours to obtain H2SO4-PANI powder;

[0058] (2) 15 mg of H2SO4-PANI powder, 2 mL of isopropyl alcohol, and 60 μL of perfluorosulfonic acid resin were mixed and ultrasonicated for 30 min to obtain a catalyst ink, which was sprayed onto a Cu-based electrocatalyst to obtain an electrocatalyst. The H2SO4-PANI loading in the electrocatalyst was 0.5 mg / cm 2 .

[0059] Comparative Example 4:

[0060] The difference between this comparative example and Example 1 is that hydrochloric acid is used instead of 2-aminobenzenesulfonic acid. The specific steps are as follows:

[0061] (1) 0.012 mol of hydrochloric acid and 0.01 mol of aniline were mixed to obtain a mixture; the mixture was placed in a mortar and ground for 10 minutes until the mixture formed a uniform white paste; then 0.01 mol of ammonium persulfate was added and ground for 30 minutes to perform a coupling reaction to obtain a polymer; the polymer was washed three times with ultrapure water and ethanol, and then vacuum dried at 60°C for 12 hours to obtain HCl-PANI powder;

[0062] (2) 15 mg of ABSA-PANI powder, 2 mL of isopropyl alcohol, and 60 μL of perfluorosulfonic acid resin were mixed and ultrasonicated for 30 min to obtain a catalyst ink. The catalyst ink was sprayed onto the Cu-based electrocatalyst prepared in Example 1 to obtain an electrocatalyst. The loading amount of ABSA-PANI in the electrocatalyst was 0.5 mg / cm 2 .

[0063] Test Example 1:

[0064] The electrocatalyst based on the cationic conductive modified layer prepared in Example 1 and the electrocatalysts prepared in Comparative Examples 1-4 were structurally characterized. Figure 1-Figure 3 shown.

[0065] Depend on Figure 1It can be seen that the cationic conductive modification layer formed by ABSA-PANI has an obvious porous structure, and the cationic conductive modification layer is evenly distributed and tightly terminated with the copper nanoparticle catalyst layer to ensure that the electrocatalyst based on the cationic conductive modification layer can ensure rapid ion diffusion and rapid material transport during use.

[0066] Figure 2 : The Fourier transform infrared spectra of the electrocatalysts prepared in Comparative Examples 1-4 and Example 1. Figure 2 It can be seen that at 1631, 1502 and 1341 cm- 1 There are absorption peaks at 3148 and 1138 cm-1, which correspond to the quinone nitrogen stretching vibration, benzene nitrogen stretching vibration and carbon-nitrogen stretching vibration, respectively. All the above results confirm the successful synthesis of PANI. However, compared with PANI, the absorption peaks of doped PANI at 3148 and 1138 cm-1 are significantly higher than those of PANI. 1 The absorption peaks at NH and NH are enhanced, corresponding to the stretching vibration of NH and the characteristic band of protonated PANI (-NH- + These two characteristic peaks confirm the successful doping of PANI. However, under the same conditions, different proton acids have different doping degrees on PANI. Among them, organic acids, especially ABSA, have a higher doping degree on PANI and are more stable.

[0067] Figure 3 The N1s X-ray photoelectron spectra of the electrocatalysts prepared in Example 1 and Comparative Example 1 are shown in FIG. Figure 3 The N1s signal can be decomposed into four sub-peaks at 398.5, 399.6, 400.7, and 401.9 eV, corresponding to the quinone-N group (-N=), the phenyl-N group (-NH-), and the positively charged nitrogen bonds (-NH-+ and =NH2+-), respectively. The degree of PANI doping can be further characterized by the percentage of protonated N in the N1s spectrum, showing a significant increase in the protonation of the imine and amine groups in the doped PANI.

[0068] Test Example 2:

[0069] The Cu / ABSA-PANI prepared in Example 1, the Cu / PANI prepared in Comparative Example 1, and the Cu-based catalyst (Cu) prepared in step (2) of Example 1 were used as electrocatalysts, and a flow cell electrolyzer was used to conduct a CO2 electrocatalytic reduction test. A proton exchange membrane (Nafion 117) was used to effectively separate the cathode and anode compartments in the flow cell electrolyzer.

[0070] The specific steps are as follows:

[0071] (1) During the test, an acidic electrolyte was used, which consisted of KCl and H2SO4, with a KCl concentration of 1M and a H2SO4 concentration of 0.05M. An Ag / AgCl electrode was used as a reference electrode, and a Pt foil was used as a counter electrode. The CO2 gas flow rate was controlled to be constant at 20 sccm, and different current densities (200, 300, 400, 500 mA / cm 2 ), the circulation flow rate of the cathode electrolyte and the anolyte was 10 mL min- 1 .

[0072] (2) After the reaction is completed, the gaseous products and liquid products are quantitatively analyzed by gas chromatography and nuclear magnetic resonance, respectively. The specific process is that the gaseous products after the reaction directly enter the gas chromatograph (Agilent GC7890) after the CO2RR cell, and the flame ionization detector (FID) is used to detect CO, CH4, C2H4, C2H2, C3H6, C3H8 and C4H8, and the thermal conductivity detector (TCD) is used to detect H2, so as to determine the amount of gaseous products. The liquid product is sampled from the cathode electrolyte with a syringe after the constant potential reaction, and 500μL of the collected electrolyte is mixed with 100μL D2O (heavy water) and 0.05μL dimethyl sulfoxide (DMSO, as an internal standard). After the water peak is suppressed by the pre-saturation method, it is passed through 1 H NMR ( 1 H-NMR) analysis was performed to determine the amount of liquid product, and then the Faradaic efficiency (FE) was calculated. The results are as follows: Figure 4 and Figure 5 shown.

[0073] The calculation formula of Faraday efficiency is:

[0074]

[0075] Where e is the number of electrons transferred to the different products, F is the Faraday constant (96485C / mol), n is the total amount of substance of the different products (in mol), and Q is the total charge. 2+ When the Faradaic efficiency of the product is different, C 2+ The FE of the products are added.

[0076] (3) Electrodes loaded with different electrocatalysts (Cu, Cu / PANI, and Cu / ABSA-PANI) were selected and placed in an electrolyte containing 0.05 M H2SO4 and 1 M KCl at 600 mA cm -2 The reaction was continued for 120s to allow K to be adsorbed on the catalyst surface. + reach a relatively stable state.

[0077] After the reaction is completed, the electrode is quickly removed from the electrolyte and directly transferred to 10 mL of ultrapure water. During the transfer process, the electrode voltage is always kept constant to maintain the electrochemical state of the electrode surface and ensure that the adsorbed K + No premature desorption due to voltage changes. After the electrode is immersed in ultrapure water, the voltage is removed. At this time, K adsorbed on the catalyst surface + The K-containing + Ultrapure water was tested to determine the K + The concentration of Figure 6 shown.

[0078] Figure 6 Comparison of the concentration of potassium ions adsorbed on the surface of different electrocatalysts. Figure 6 It can be seen that the surface K + The adsorption capacity is higher than that of Cu-based electrocatalysts. Among them, the surface adsorption of K + The concentration of ABSA-PANI is 2.1 times that of the Cu-based catalyst in the control group. + concentration, thereby achieving CO2 activation and reduction. This is crucial for achieving efficient acidic CO2RR at low basic cation concentrations.

[0079] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for preparing an electrocatalyst based on a cationic conductive modified layer, characterized in that: The steps include: (1) mixing 2-aminobenzenesulfonic acid and aniline and grinding them to obtain a mixture; adding ammonium persulfate to the mixture to react, and after the reaction is completed, washing and drying to obtain a cationic conductive modified material; (2) A cationic conductive modifying material, isopropyl alcohol, and a binder are mixed and ultrasonically treated to obtain a catalyst ink, and the catalyst ink is sprayed onto a Cu-based electrocatalyst to obtain an electrocatalyst based on a cationic conductive modifying layer.

2. The method for preparing an electrocatalyst based on a cationic conductive modified layer according to claim 1, wherein: In step (1), the molar ratio of aniline, ammonium persulfate and 2-aminobenzenesulfonic acid is 1:(0.5-1):(0.5-1).

3. The method for preparing an electrocatalyst based on a cationic conductive modified layer according to claim 1, wherein: In step (1), the grinding time is 5-15 min; and the reaction time is 20-40 min.

4. The method for preparing an electrocatalyst based on a cationic conductive modified layer according to claim 1, wherein: In step (2), the Cu-based electrocatalyst is prepared by the following method: Copper nanoparticles, isopropyl alcohol and perfluorosulfonic acid resin are mixed and ultrasonically treated, and the ultrasonically treated system is sprayed onto a GDE electrode to form a copper nanoparticle catalyst layer, thereby obtaining a Cu-based electrocatalyst.

5. The method for preparing an electrocatalyst based on a cationic conductive modified layer according to claim 4, wherein: The addition ratio of copper nanoparticles, isopropyl alcohol and perfluorosulfonic acid resin was (15-20) mg:2 mL:100 μL; In Cu-based electrocatalysts, the loading of copper nanoparticles is 0.4-0.6 mg / cm 2 .

6. The method for preparing an electrocatalyst based on a cationic conductive modified layer according to claim 1, wherein: In step (2), the loading amount of the cationic conductive modifying material in the electrocatalyst based on the cationic conductive modifying layer is 0.4-0.6 mg / cm 2 .

7. The method for preparing an electrocatalyst based on a cationic conductive modified layer according to claim 1, wherein: The added amount ratio of the cationic conductive modifying material, isopropyl alcohol and adhesive is (10-20) mg:2 mL:60 μL.

8. An electrocatalyst based on a cationic conductive modified layer prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the electrocatalyst based on the cationic conductive modified layer according to claim 8 in electrocatalytic CO2 reduction.

10. The use according to claim 9, characterized in that During the electrocatalytic CO2 reduction process, an acidic electrolyte is used; in the acidic electrolyte, the concentration of KCl is 0.8-1.2M and the concentration of H2SO4 is 0.04-0.06M.

Images