Graphdiyne-loaded doped copper-based nano electrocatalyst, preparation method and application of graphdiyne-loaded doped copper-based nano electrocatalyst in CO2 resource utilization

Abstract

The invention discloses a graphdiyne-loaded doped copper-based nano electrocatalyst, a preparation method and application of the graphdiyne-loaded doped copper-based nano electrocatalyst in CO2 resource utilization, and the preparation method comprises the following steps: under protective gas, mixing and stirring CuCl, Al (NO3) 3.9 H2O, CH4N2S, graphdiyne and a solvent, and gradually dropwise adding 1-butyl-3-methylimidazolium tetrafluoroborate to obtain a mixed solution; the mixed solution is heated, cooled to the room temperature, washed and dried, and then the graphdiyne-loaded doped copper-based nano electrocatalyst is obtained, a stability test is conducted on the GDY-Al-Cu2Sv catalyst prepared through the method under the current density of 500 mA cm <-2 >, and the GDY-Al-Cu2Sv catalyst can be stabilized under 45 h electrolysis, the stability is 70% or above, and the stability is kept 55% or above.

Description

Technical Field

[0001] This invention belongs to the field of copper-based nano-electrocatalyst technology, and in particular relates to a graphdiyne-supported doped copper-based nano-electrocatalyst, its preparation method, and its application in CO2 resource utilization. Background Technology

[0002] With the rapid development of the global economy, the long-term and large-scale use of fossil fuels has led to a continuous rise in atmospheric CO2 concentration, resulting in severe ecological and environmental problems such as the exacerbation of the greenhouse effect. Currently, converting excess CO2 into high-value-added chemicals through capture technology is a promising CO2 treatment solution.

[0003] Electrochemical CO2RR, driven by renewable electricity, is considered one of the most promising CO2 conversion technologies, efficiently converting CO2 into high-energy-density and economically viable C2 / C2. 2+ This is considered the most feasible technological path. Currently, ethanol is a promising product due to its high energy density and consistent global demand. Nevertheless, only a few studies have reported satisfactory FE (efficiency / energy density). C2H5OH The slow C-C coupling process and a series of decisive intermediates lead to low selectivity for the target product, limiting its practical application. Improving the selectivity of ethanol is a key challenge in the design of novel electrocatalysts. Due to the limited selectivity and low activity of current catalysts, the production of ethanol through direct electroreduction of CO2 remains below the level required for economic feasibility. To develop more efficient ethanol electrocatalysts, it is crucial to modify the catalyst structure to promote the electrosynthesis of the desired alcohol and inhibit the electrosynthesis of olefins. Cu is currently the only catalytic material capable of converting CO2 to multi-carbon products; however, single-component copper-based catalysts still suffer from insufficient stability and low product selectivity in practical applications. It is believed that ethanol and ethylene are derived from... * Derived from shared intermediates of CH2CHO, they often exhibit strong competition in the CO2RR pathway. An ideal catalyst for ethanol production should be stable. * The CO bond in CH2CHO, and reduce * In CH2CHO, the weaker Cu-C and Cu-O bonds are more favorable. * The CH2CHO intermediate is converted into ethanol.

[0004] By doping other metal elements into copper-based catalysts, their catalytic performance can be effectively improved, and cuprous sulfide structures are of interest because they can provide a means of forming stable surface defects and controlling surface vacancy density. In addition, cuprous sulfide derived catalysts are worth studying because the introduction of sulfur into the Cu structure modifies the local density of surface states over long distances and affects CO binding. Edward H. Sargent et al. designed a class of core-shell vacancy engineered catalysts as early as 2018, which use sulfur atoms in the nanoparticle core and copper vacancies in the shell to achieve efficient electrochemical CO2RR to propanol and ethanol. These catalysts transfer selectivity from the competitive ethylene reaction to liquid alcohols. Compared with bare copper nanoparticles, this strategy increases the ratio of ethanol to ethylene by more than six times, highlighting the advantages of alternative routes for electrocatalytic production of alcohols rather than olefins. As metal ions (such as Al 3+ and Cr 3+ ) with electron-deficient structures, and S vacancies with electron-deficient properties can regulate the electronic structure of active center copper, thereby promoting CO2RR by optimizing the activation energy barrier of intermediates. Therefore, using S and Al to regulate the performance of copper-based nanomaterials for electrocatalytic CO2RR is an important strategy. SUMMARY

[0005] Therefore, the present application aims to provide a graphdiyne supported doped copper-based nanoelectrocatalyst and a preparation method thereof and its application in CO2 resource utilization, so as to solve at least one technical problem in the background art.

[0006] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0007] The preparation method of the graphdiyne supported doped copper-based nanoelectrocatalyst comprises the following steps: mixing and stirring CuCl, Al(NO3)3·9H2O, CH4N2S, graphdiyne and a solvent under a protective gas, and gradually adding 1-butyl-3-methylimidazolium tetrafluoroborate to obtain a mixed solution;

[0008] The mixed solution is heated, cooled to room temperature, washed and dried to obtain the graphdiyne supported doped copper-based nanoelectrocatalyst.

[0009] Further, the molar ratio of CuCl, Al(NO3)3·9H2O and CH4N2S is 1:0.9-1.1:0.9-1.1.

[0010] Further, the solvent comprises deionized water and isopropyl alcohol.

[0011] And / or, the protective gas comprises one of nitrogen, helium, argon, neon, krypton and xenon.

[0012] And / or, the volume ratio of deionized water and isopropyl alcohol is 1:3.8-4.2.

[0013] And / or, the mixing stirring time is 4-6 min.

[0014] Further, the heating temperature of the mixed solution is 55-65 DEG C, and the heating time is 2.5-3.5 h.

[0015] Further, the washing and drying include washing the sample multiple times with a mixture of deionized water and ethanol, and then vacuum drying, wherein the vacuum drying temperature is 55-65 DEG C, and the vacuum drying time is 22-26 h.

[0016] The volume ratio of the deionized water and the ethanol mixture is 1:0.8-1.2.

[0017] Further, the preparation of the graphdiyne includes the following steps: mixing hexakis(trimethylsilyl ethynyl) benzene, CuCl and N, N-dimethylformamide, sealing and heating to 55-65 DEG C for 22-26 h, obtaining CuO / GDY after the reaction is completed, washing the CuO / GDY with N, N-dimethylformamide, dichloromethane, tetrahydrofuran and methanol in sequence, etching the washed sample by adding HCl, and obtaining the graphdiyne after post-processing.

[0018] Further, the post-processing includes washing the sample twice with deionized water, and then washing once with acetone, and then naturally air-drying the sample after centrifugation to obtain the graphdiyne.

[0019] The graphdiyne loaded doped copper-based nanoelectrocatalyst prepared by the preparation method of the graphdiyne loaded doped copper-based nanoelectrocatalyst.

[0020] The graphdiyne loaded doped copper-based nanoelectrocatalyst prepared by the preparation method of the graphdiyne loaded doped copper-based nanoelectrocatalyst is applied to CO2 resource utilization.

[0021] Compared with the prior art, the graphdiyne loaded doped copper-based nanoelectrocatalyst and the preparation method thereof and the application thereof in CO2 resource utilization have the following advantages:

[0022] The application in-situ prepares Al-doped Cu2S nanomaterials with sulfur vacancies on a GDY substrate. The morphology and structure of the material are tested by various characterization methods, and the subsequent performance test and theoretical calculation results show that, due to the unique structure of the graphdiyne and the synergistic effect with copper, the GDY-Al-Cu2S v The material exhibits a significant selectivity advantage for C2H5OH, and at a potential of-1.5 V vs. RHE, the FE C2H5OH of the material is 58.4%, and the FE C2The percentage reached 77%, with FE (electron-deficient ferrite) in carbon-containing products exceeding 90%. This was influenced by the regulation of GDY, the increase of vacancies, and the electron-deficient Al... 3+ Regulation enhances the catalyst's resistance to... * The increased CO coverage simultaneously lowers the energy barrier for CC coupling, promoting subsequent CC coupling. * COCO, thereby improving the selectivity of CO2RR to the target product. Finally, GDY-Al-Cu2S v Catalyst at 500 mA cm -2 Stability tests were conducted at the specified current density, and it remained stable for 45 hours under electrolysis. C2 At over 70%, FE C2H5OH Maintaining a content above 55%. This application provides a new strategy for designing and synthesizing copper-based nanomaterials for highly efficient electrocatalytic CO2RR. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0024] Figure 1 This is a schematic diagram of the preparation method of the graphdiyne-supported doped copper-based nano-electrocatalyst proposed in this invention.

[0025] Figure 2 SEM images of embodiments and comparative examples of the present invention (a is GDY-Al-Cu2S) v SEM image, b is Al-Cu2S v SEM images of Al-Cu2S, Ga-Cu2S, In-Cu2S, and Cu2S (c is the SEM image of Al-Cu2S, d is the SEM image of Ga-Cu2S, e is the SEM image of In-Cu2S, and f is the SEM image of Cu2S).

[0026] Figure 3 Transmission electron microscope (TEM) images of embodiments and comparative examples of the present invention (a is GDY-Al-Cu2S). v Transmission electron microscopy image, b is Al-Cu2S v The transmission electron microscope (TEM) images are shown in Figure 1. c is the TEM image of Al-Cu2S, d is the TEM image of Ga-Cu2S, e is the SEM image of In-Cu2S, and f is the TEM image of Cu2S.

[0027] Figure 4 The images shown are transmission electron microscope (TEM) images and EDS elemental diagrams of embodiments of the present invention (a is GDY-Al-Cu2S). v Transmission electron microscopy image, b is GDY-Al-Cu2S vTransmission electron microscope image (inset is a magnified view), c is the HAADF image, and the corresponding EDS elemental images of Cu, Al, S and C);

[0028] Figure 5 The GDY-Al-Cu2S of the present invention v Al-Cu2S v Electron paramagnetic resonance spectra of Al-Cu2S;

[0029] Figure 6 Raman spectra for embodiments and comparative examples of the present invention (a is the Raman spectrum of GDY, b is the Raman spectrum of GDY-Al-Cu2S) v (Raman map);

[0030] Figure 7 The GDY-Al-Cu2S of the present invention v Al-Cu2S v CO2 isothermal adsorption curves of Al-Cu2S, Ga-Cu2S, In-Cu2S and Cu2S;

[0031] Figure 8 The GDY-Al-Cu2S of the present invention v Al-Cu2S v XRD patterns of Al-Cu2S, Ga-Cu2S, In-Cu2S and Cu2S;

[0032] Figure 9 The GDY-Al-Cu2S of the present invention v XPS spectra (a is the overall spectrum, b is Cu 2p, c is Cu LMM; d is C1s, e is Al 2p, f is S2p);

[0033] Figure 10 The Cu foil, Cu2S, CuS, and GDY-Al-Cu2S of this invention v and Al-Cu2S v a is the Cu K-edge X-ray absorption near-edge structure spectrum and b is the extended X-ray absorption fine structure spectrum in R space;

[0034] Figure 11 The GDY-Al-Cu2S of the present invention v and Al-Cu2S v Comparison of Cu 2p spectra;

[0035] Figure 12 The GDY-Al-Cu2S of the present invention v Al-Cu2S vLinear sweep voltammetric curves of Al-Cu2S, Ga-Cu2S, In-Cu2S and Cu2S in CO2 atmosphere;

[0036] Figure 13 Faraday efficiency diagrams of embodiments and comparative examples of the present invention at different potentials (a is GDY-Al-Cu2S) v Faraday efficiency plots at different potentials, where b represents Al-Cu2S v The Faraday efficiency diagrams at different potentials are shown in Figures c, d, e, and f. (c represents the Faraday efficiency diagram of Al-Cu2S at different potentials, d represents the Faraday efficiency diagram of Ga-Cu2S at different potentials, e represents the Faraday efficiency diagram of In-Cu2S at different potentials, and f represents the Faraday efficiency diagram of Cu2S at different potentials).

[0037] Figure 14 The GDY-Al-Cu2S of the present invention v Al-Cu2S v FE diagrams of Al-Cu2S and Cu2S under -1.5V vs. RHE for C2, C2H5OH and C2H4;

[0038] Figure 15 This invention relates to GDY-Al-Cu2S at different potentials. v Al-Cu2S v Al-Cu2S and Cu2S have α as FE C2 / FE C1 b is the partial current density of C2 and c is the average current density;

[0039] Figure 16 The present invention is GDY-Al-Cu2S v Comparison of ethanol production performance (current density and Faraday efficiency) with other copper-based electrocatalysts in CO2RR;

[0040] Figure 17 The present invention is GDY-Al-Cu2S v At 500mA cm -2 Stability test graph below;

[0041] Figure 18 The present invention is GDY-Al-Cu2S v Transmission electron microscope (TEM) images of different time regions in CO2RR testing (a is TEM image at 0.5 h, b is TEM image at 1 h, c is TEM image at 45 h, and d–f are magnified high-resolution transmission electron microscope (TEM) images of the corresponding regions).

[0042] Figure 19The transmission electron microscope (TEM) and EDS elemental diagrams of GDY-Al-Cu2Sv CO2RR after testing are shown in the figure (a is the TEM image, b is the HAADF image, and the corresponding EDS elemental diagrams of Cu, Al, S and C).

[0043] Figure 20 The present invention is GDY-Al-Cu2S v and GDY-Al-Cu2S v XRD patterns at 0.5h, 1h and 45h after CO2RR test;

[0044] Figure 21 This invention relates to GDY-Al-Cu2S under OCP and -1.5V vs. RHE conditions. v a represents the near-edge structure X-ray absorption spectrum of Cu k-edge and b represents the fine structure X-ray absorption spectrum of the extended R space.

[0045] Figure 22 GDY-Al-Cu2S after CO2RR test of the present invention v and Al-Cu2S v Electron paramagnetic resonance spectrum;

[0046] Figure 23 Contact angle tests for embodiments and comparative examples of the present invention (a is GDY-Al-Cu2S) v Contact angle test diagram, b is Al-Cu2S v (Contact angle test diagrams for: c) Al-Cu2S, d) Ga-Cu2S, e) In-Cu2S, and f) Cu2S.

[0047] Figure 24 Cyclic voltammetry curves and electrochemical double-layer capacitance plots of embodiments and comparative examples of the present invention (a is GDY-Al-Cu2S) v b is Al-Cu2S v c represents Al-Cu2S, d represents Ga-Cu2S, and e represents In-Cu2S at different scan rates in the non-Radida potential range; f represents the electrochemical double-layer capacitance plot.

[0048] Figure 25 The GDY-Al-Cu2S of the present invention v Al-Cu2S v Electrochemical impedance spectroscopy of Al-Cu2S, Ga-Cu2S, In-Cu2S and Cu2S;

[0049] Figure 26 The GAY-Al-Cu2S of the present invention v and Al-Cu2Sv KIE performance of H / D at -1.5V vs. RHE in CO2RR to C2H4;

[0050] Figure 27 Al-Cu2S and GDY-Al-Cu2S of the present invention v In-situ infrared spectra at different potentials (a: Al-Cu2S at different potentials; b: Al-Cu2S at -1.5V vs. RHE potential for different times; c: GDY-Al-Cu2S) v In-situ infrared spectra of GDY-Al-Cu2S at different potentials and d for different times at -1.5V vs. RHE potential;

[0051] Figure 28 GDY-Al-Cu2S v and Al-Cu2S v Infrared spectral comparison (a is GDY-Al-Cu2S) v b is Al-Cu2S v At different potentials during the CO2 electroreduction process * In-situ infrared spectra of CO peaks, where c represents GDY-Al-Cu2S at different potentials. v and Al-Cu2S v HFB / LFB ratio, d represents GDY-Al-Cu2S at different potentials v and Al-Cu2S v of * (Comparison chart of OC2H5OH peak areas);

[0052] Figure 29 The GDY-Al-Cu2S of the present invention v and Al-Cu2S v Electrochemical CO dissolution voltammetry test results;

[0053] Figure 30 The in-situ Raman spectra of v at different potentials during the CO2 electroreduction process (a is GDY-Al-Cu2S) v b is Al-Cu2S v In-situ Raman spectra at different potentials during the CO2 electroreduction process;

[0054] Figure 31 The GDY-Al-Cu2S of the present invention v and Al-Cu2S v A graph showing the ratio of Cu-CO rotational vibration to Cu-CO stretching bands;

[0055] Figure 32The calculation model of this invention (a is GDY-Al-Cu2S) v The calculation model, where b is Al-Cu2S v (Computational model);

[0056] Figure 33 The present invention is GDY-Al-Cu2S v and Al-Cu2S v Simulated reaction energy diagrams and water dissociation free energy diagrams on Cu2S(204) (a is the reaction energy diagram of CO2 conversion to ethanol or ethylene, b is the water dissociation free energy diagram);

[0057] Figure 34 GDY-Al-Cu2S v and Al-Cu2S v The simulated Cu2S(204) a represents the Cu 3d orbital and * PDOS diagram of CH2CHO adsorption, b is... * PDOS diagrams of the O 2p and C 2p orbitals adsorbed on CH2CHO and c represent the values ​​at... * The C-Obond p in CH2CHO COHP curve;

[0058] Figure 35 GDY-Al-Cu2S v (above) and Al-Cu2S v (Below) Simulated Cu2S(204) (above) * CH2CHO and * CH3CHO adsorbs the charge state of Cu sites. Detailed Implementation

[0059] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0060] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0061] Example 1

[0062] Synthesis of GDY: 168 mg of hexa(trimethylsilylethynyl)benzene, 24 mg of CuCl, and 20 mL of DMF were added to a 50 mL glass bottle. The bottle was then sealed and heated to 60 °C for 24 h. After the reaction, the sample was washed sequentially with N,N-dimethylformamide, dichloromethane, tetrahydrofuran, and methanol. The washed sample was then etched with 0.5 M HCl to remove CuO / GDY, yielding pure GDY. Finally, the sample was washed twice with deionized water, once with acetone, centrifuged, and air-dried in a ventilated area to obtain graphyne.

[0063] Example 2

[0064] Under a nitrogen atmosphere, in a glass flask, 1 mmol of CuCl, 1 mmol of Al(NO3)3·9H2O, 1 mmol of CH4N2S, and 10 mg of graphyne (GDY) prepared in Example 1 were dispersed in a mixed solvent of 10 mL deionized water and 40 mL isopropanol, and then stirred for 5 minutes. Next, 100 μL of an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) was added dropwise to the solution. Finally, the solution was heated to 60 °C and held at this temperature for 3 hours, then cooled to room temperature. The product was washed three times with a 1:1 volume ratio of deionized water and ethanol, and then dried in a vacuum drying oven at 60 °C for 24 hours to obtain a white powder, named GDY-Al-Cu2S. v .

[0065] Comparative Example 1

[0066] In a glass bottle, CuCl, Al(NO3)3·9H2O, and CH4N2S in a molar ratio of 1:1:1 were dispersed in 10 mL of deionized water and 40 mL of isopropanol, respectively, and stirred for 5 min. The solution was then heated to 60 °C, held at that temperature for 3 hours, and then cooled to room temperature. After washing three times with a 1:1 volume ratio of deionized water and ethanol, the solution was dried in a vacuum drying oven at 60 °C for 24 h to obtain a white powder, namely Al-Cu2S.

[0067] Comparative Example 2

[0068] In a glass bottle, CuCl, Ga(NO3)3·3H2O, and CH4N2S were dispersed in a molar ratio of 1:1:1 in 10 mL of deionized water and 40 mL of isopropanol, respectively, and stirred for 5 min. The solution was then heated to 60 °C, held at that temperature for 3 hours, and then cooled to room temperature. After washing three times with a volume ratio of 1:1 deionized water and ethanol, the solution was dried in a vacuum drying oven at 60 °C for 24 h to obtain a white powder, namely Ga-Cu2S.

[0069] Comparative Example 3

[0070] In a glass bottle, CuCl, In(NO3)3·3H2O, and CH4N2S in a molar ratio of 1:1:1 were dispersed in 10 mL of deionized water and 40 mL of isopropanol, respectively, and stirred for 5 min. The solution was then heated to 60 °C, held at that temperature for 3 hours, and then cooled to room temperature. After washing three times with a 1:1 volume ratio of deionized water and ethanol, the solution was dried in a vacuum drying oven at 60 °C for 24 h to obtain a white powder, namely In-Cu2S.

[0071] Comparative Example 4

[0072] In a glass bottle, CuCl, Al(NO3)3·9H2O, and CH4N2S in a molar ratio of 1:1:1 were dispersed in 10 mL of deionized water and 40 mL of isopropanol, respectively, and stirred for 5 min. Then, 100 μL of an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) was added dropwise to the solution. The solution was then heated to 60 °C, held at that temperature for 3 hours, and then cooled to room temperature. After washing three times with deionized water and ethanol in a 1:1 volume ratio, the solution was dried in a vacuum drying oven at 60 °C for 24 h to obtain a white powder, yielding Al-Cu2S. v .

[0073] Comparative Example 5

[0074] In a glass bottle, CuCl and CH4N2S were dispersed in a 1:1 molar ratio in 10 mL of deionized water and 40 mL of isopropanol, respectively, and stirred for 5 min. Then, the solution was heated to 60 °C, held at that temperature for 3 hours, and then cooled to room temperature. After washing three times with a 1:1 volume ratio of deionized water and ethanol, the solution was dried in a vacuum drying oven at 60 °C for 24 h to obtain a white powder, which is Cu2S.

[0075] test

[0076] Electrode preparation and electrochemical testing were performed at room temperature using CHI 760E and CHI 1140E electrochemical workstations. A standard three-electrode configuration was used: a Pt mesh as the counter electrode and an Ag / AgCl electrode as the reference electrode. The working electrode was prepared as follows: 7 mg of catalyst was mixed with 1 mL of isopropanol (containing 180 μL of Nafion solution) and ultrasonically treated to form a uniformly dispersed catalyst ink. Subsequently, an appropriate amount of ink was uniformly loaded onto a carbon paper substrate using a drop-coating method, and finally dried using an infrared lamp. The catalyst loading of the working electrode prepared by the above process was controlled at 1.0 mg / cm³. -2 .

[0077] First, the morphology of the prepared catalyst was characterized by SEM, such as... Figure 2 As shown. Figure 2 The af is GDY-Al-Cu2S v Al-Cu2S v SEM images of Al-Cu2S, Ga-Cu2S, In-Cu2S and Cu2S show that the synthesized catalysts all exhibit a long, rod-like configuration.

[0078] TEM further revealed that the sample morphology was mainly elongated rod-shaped. Figure 3 The af values ​​are GDY-Al-Cu2S respectively. v Al-Cu2S v, Transmission electron microscope (TEM images) of Al-Cu2S, Ga-Cu2S, In-Cu2S and Cu2S. It can be seen from the figure that after adding the ionic liquid, the surface of Al-Cu2S v presents a rough and defective hollow configuration, and the loading of GDY makes the hollow shape of the catalyst more obvious. Through Figure 4 the red "work" character mark in a, the attachment of the GDY layer on Al-Cu2S v can be observed, Figure 4 b shows lattice fringes with interplanar spacings of 0.33 nm and 0.25 nm, which can be attributed to the (104) and (204) crystal planes of Cu2S (PDF: 33-0490), indicating that the main crystal phase formed in GDY-Al-Cu2S v is Cu2S. After magnifying and processing the lattice fringe image in Figure 4 b by selected area, the inverse Fourier transform image (inset) is obtained. It can be clearly seen that there are a large number of defects on this crystal plane at the place circled in red in the figure. Figure 4 c The EDS diagram proves the uniform distribution of Cu, Al, S, and C elements.

[0079] The synthesized catalyst was tested by EPR. As Figure 5 shown, it can be seen that after adding the ionic liquid, the catalyst generates S vacancies (signals at g = 2.003), indicating that the hollow structure of the catalyst comes from the addition of the ionic liquid. The ionic liquid acts as a structure-directing agent to regulate the structure of the catalyst. This corresponds to Figure 4 the defects circled in red in the inset of b. It is further shown from the EPR diagram that the loading of GDY can increase the S vacancies, which is due to the synergistic effect of GDY and Al-Cu2S v . During the in-situ synthesis process, the alkyne bonds in GDY are connected to Cu, enabling precise regulation of the valence state of Cu in GDY-Al-Cu2S v . The originally obvious defect level in the structure ensures effective electron transfer between Al-Cu2S v and GDY, resulting in further increase of S vacancies in GDY-Al-Cu2S v .

[0080] Next, Raman spectrometers were used to characterize GDY and GDY-Al-Cu2S v . As Figure 6 shown, both materials exhibit the characteristic peaks of the D peak, G peak and alkyne bond structure (-C≡C-C≡C-) of GDY. It can be seen from the figure that the alkyne bond structure peak of GDY has shifted, from 1945 cm -1 to 1955 cm -1 , from 2118 cm -1Offset to 2155cm -1 GDY and Al-Cu2S were further identified. v The combination of GDY-Al-Cu2S proves v Successful synthesis.

[0081] Studies have found that a hollow catalyst morphology exhibits higher CO2 absorption rates and more efficient charge transport, providing numerous pathways for ion transport and thus contributing to improved catalytic performance.

[126] Therefore, to further investigate the effect of the hollow structure of the material on CO2 adsorption performance, we conducted CO2 adsorption experiments. From Figure 7 It can be seen from this that GDY-Al-Cu2S v This demonstrates a higher adsorption and capture capacity for CO2, which is more conducive to promoting electrocatalytic CO2 RR. This indicates that GDY-Al-Cu2S... v It can adsorb more CO2 on its surface, providing a more favorable electrolysis environment for subsequent CO2RR.

[0082] Next, we performed XRD tests on the prepared catalyst, such as... Figure 8 As shown, it is evident that the six catalysts primarily exhibit the Cu₂S phase (PDF: 33-0490), and the addition of main group elements did not alter the crystal phase of the catalysts; however, no characteristic peaks of the doped elements were observed. Further analysis of the target sample GDY-Al-Cu₂S... v ICP-AES testing confirmed that the aluminum atom content was 0.5 at.%, as shown in Table 3.1.

[0083] Table 1 GDY-Al-Cu2S v The metal content of Al in the medium.

[0084] Samples Al / wt% GDY-Al-Cu2S v ]]> 0.5

[0085] Since Al doping is more conducive to CO2RR to C2 products than Ga and In doping in the subsequent performance tests, the subsequent characterization will mainly focus on Al doping. Figure 9 a is GDY-Al-Cu2S v The XPS spectrum shows that the material contains most of the elements. Figure 9 b is GDY-Al-Cu2S v The Cu 2p spectrum clearly shows two significant characteristic peaks (binding energies of 932.8 eV and 952.8 eV, respectively), corresponding to Cu... 0 / 1+ 2p 3 / 2 and 2p 1 / 2In addition, a weak characteristic peak of divalent copper was detected in the spectrum, which is speculated to be due to surface oxidation of the sample in air. To further confirm the chemical valence state of copper, we analyzed the Cu LMM spectrum. Figure 9 c) The results show that copper in the sample mainly exists in the +1 oxidation state, with small amounts of 0-valent and +2-valent copper also present. In GDY-Al-Cu2S v C1s spectrum ( Figure 9 In d), the characteristic peaks at 284.8 eV, 285.4 eV, 287.8 eV, and 289.5 eV are assigned to CC(sp) respectively. 2 In addition to the characteristic peaks at 292.2 eV, which can be attributed to π-π, there are also peaks at C(sp), Cu-C, and C=O. * Transition peak

[127] This proves that GDY-Al-Cu2S v There is an electronic interaction between it and GDY. Figure 9 e GDY-Al-Cu2S v In the Al 2p spectrum, the two characteristic peaks at 74.1 eV and 77.8 eV are attributed to Al-Al bonds and Al... 3+ (Al-S). In S2p( Figure 9 The two main characteristic peaks (163.1 and 164.3 eV) observed in f) are attributed to S2p. 3 / 2 and S2p 1 / 2 The characteristic peak at 162.5 eV is attributed to the Cu-S bond.

[0086] X-ray absorption spectroscopy (XAS) was used to study GDY-Al-Cu2S v and Al-Cu2S v The Cu k-edge was analyzed to understand the oxidation state and local microstructure of Cu. Figure 10 a is GDY-Al-Cu2S v Al-Cu2S v Normalized Cu k-edge XANES spectra were obtained using commercial copper foil, Cu₂S, and CuS as reference samples. It can be seen that the absorption edges of both samples highly overlap with the absorption edge of the reference sample Cu₂S, further confirming that copper in the catalyst mainly exists in the form of monovalent copper, which corresponds to the XPS results. The figure shows that the average oxidation state of Cu in the catalyst is between 0 and +1. Furthermore, GDY-Al-Cu₂S... v The absorption edge of GDY-Al-Cu2S is closer to the higher energy side than other catalysts, suggesting a higher Cu oxidation state. The results indicate that GDY-Al-Cu2S doped with GDY... v It has more oxidized Cu than the control sample δ+This species may provide abundant active sites for C2 product generation. EXAFS ( Figure 10 b) This shows that the Cu-Cu bond strength in the sample is very weak, with Cu-S bonds being the dominant bond. However, compared to the standard Cu₂S and CuS samples, the strength is still relatively low. Cu-S bond at the location, GDY-Al-Cu2S v The Cu-S bond underwent a positive change. The shift indicates that the introduction of Al element optimized the coordination number of Cu atoms on the surface, causing a shift in the Cu-S coordination bond.

[0087] Subsequently, GDY-Al-Cu2S v and Al-Cu2S v The Cu 2p spectrum of Al-Cu2S was compared with that of Al-Cu2S. Figure 11 With the introduction of GDY, Cu 0 / 1+ 2p 3 / 2 and 2p 1 / 2 Both main characteristic peaks shifted towards higher binding energies. Compared to the metal catalyst without GDY, the characteristic peaks of Cu showed a significant positive shift after GDY loading, indicating that Al-Cu₂S… v There is a significant charge transfer between GDY and GDY, which is related to GDY-Al-Cu2S v The results of the XPS spectra of C1s are consistent.

[0088] Electrocatalytic CO2 reduction performance characterization

[0089] To investigate GDY-Al-Cu2S v The electrocatalytic CO2RR performance of the GDY-Al-Cu2S prepared above was improved. v Al-Cu2S v Al-Cu2S, Ga-Cu2S, In-Cu2S and Cu2S catalysts were uniformly loaded onto a carbon paper substrate as working electrodes, forming a three-electrode system together with a platinum counter electrode and an Ag / AgCl reference electrode. The electrocatalytic CO2RR performance was tested in a flow electrolyzer.

[0090] First, under CO2 flow conditions, 1M KOH is used as the electrolyte, with a flow rate of 10mV / s. -1 LSV tests were performed on six catalysts at scan rates ranging from 0V to -1.9V vs. RHE. The results are as follows: Figure 12 As shown, compared with other catalysts, GDY-Al-Cu2S exhibits better performance with increasing negative potential. v It exhibits a high current density, indicating its highest CO2RR activity. Al-Cu2S vThe current density of Al-Cu2S is significantly better than that of the four comparative materials, indicating that Al-Cu2S v The introduction of sulfur vacancies creates structural defects in the material, increasing its conductivity. These results demonstrate that the introduction of GDY and sulfur vacancies successfully enhances catalytic activity.

[0091] The CO2RR performance of the synthesized catalyst was then tested in a typical mobile phase cell using 1M KOH electrolyte. CO2 was continuously introduced into the electrolyte, and the liquid product was collected and quantified after the reaction was complete. The gaseous products were quantified by gas chromatography. All product FEs detected between -1.4V and -1.9V vs. RHE were quantified, and the catalytic products were analyzed by gas chromatography and nuclear magnetic resonance spectroscopy, respectively. Figure 13 Figures a–f show the CO2RR products of six catalysts—GDY-Al-Cu2Sv, Al-Cu2Sv, Al-Cu2S, Ga-Cu2S, In-Cu2S, and Cu2S—at different potentials. The main gas-phase products are H2, CO, CH4, and C2H4, while the main liquid-phase products are HCOOH, CH3COOH, and CH3CH2OH. The figures show that the total carbon content of the GDY-Al-Cu2Sv catalyst (C...) is... total The FE of GDY-Al-Cu2Sv is greater than 90%, and the FE increases with increasing potential. C2 Exhibiting a volcanic pattern, at a low potential of -1.5V vs. RHE, the FE of the C2 product can reach up to ~77%, and the FE of ethanol can reach up to 56±2.4%. In contrast, the FEC2H5OH values ​​of the comparative samples are: Al-Cu2Sv: 28.3%, Al-Cu2S: 23%, Ga-Cu2S: 21.22%, In-Cu2S: 15.22%, and Cu2S: 10%. GDY-Al-Cu2Sv is significantly higher than other comparative samples, indicating a high FE. C2 This indicates that CO is moderately adsorbed on GDY-Al-Cu2Sv and is not easily desorbed from the surface. This enhances the CC coupling by promoting CO adsorption and H2O dissociation, thereby promoting CO2RR to generate C2 products.

[0092] Next, GDY-Al-Cu2S was compared. v Al-Cu2S v Four catalysts, Al-Cu2S, Cu2S, and Cu2S, were used in the reaction of C2, C2H5OH, and C2H4 at -1.5V vs. RHE. Figure 14 The comparison of FE showed that with the addition of GDY, the selectivity of the catalyst for C2H5OH increased, and the GDY-Al-Cu2S catalyst exhibited better selectivity. v It still exhibits optimal performance.

[0093] Comparison of GDY-Al-Cu2S at different potentials v Al-Cu2S v FE at different potentials for four working electrodes: Al-Cu2S, Cu2S, and Cu2S. C2 / FE C1 ( Figure 15 a) The GDY-Al-Cu2S v The C2 selectivity was higher than that of other comparative samples at different potentials. The figure further shows that the selectivity of the catalyst for C2 increases with the formation of vacancies. This is mainly because the generation of vacancies increases the defect level of the catalyst, thereby increasing the amount of CO2 adsorbed by the catalyst and ensuring the transformation of the C2 intermediate in the subsequent CO2RR. Figure 15 Figures b and c show the bias current density and average total current density of the four working electrodes C2 at different potentials. In contrast, GDY-Al-Cu2S v GDY-Al-Cu2S exhibits higher current density at -1.5V vs. RHE potential. v j C2 Reaching 570mA cm -2 .

[0094] To highlight our GDY-Al-Cu2S v The superiority of the catalyst will enable FE C2H5OH and j C2H5OH Benchmarking against existing technology catalysts ( Figure 16 (Table 3.2). Impressively, FE ranked first. C2H5OH and j C2H5OH GDY-Al-Cu2S v It is listed as the best-performing ethanol-directed CO2RR electrocatalyst, highlighting its practical application value.

[0095] To verify GDY-Al-Cu2S v The stability of the catalyst at 500 mA cm⁻¹ -2 Stability tests were conducted at a current density of [value missing] for 45 hours, and the change in potential was negligible. Figure 17 Meanwhile, the FE content of C2 products remained at approximately 70%.

[0096] Table 2 Comparison of the performance of copper-based catalysts in producing C2H5OH

[0097]

[0098]

[0099] GDY-Al-Cu2S vCO2RR post-test

[0100] The catalyst after stability testing was characterized by HRTEM, XRD, and XPS analysis. We conducted a detailed observation of the in-situ conversion process, obtaining GAY-Al-Cu2S at different electrochemical reduction times. v TEM images such as Figure 18 As shown in a–c. The results indicate that GAY-Al-Cu2S v After electrolytic reduction for 1 hour, GDY-Al-Cu2S v The hollow structure transformed into a solid rod-like structure, and after 45 hours of continued electrolytic reduction, the morphology of the catalyst did not change further. HRTEM images show ( Figure 18 d–f), GDY-Al-Cu2S v After 1 hour of electrolysis, the lattice spacings were 0.25 nm and 0.20 nm, corresponding to the (204) plane of Cu₂S and the (111) plane of Cu, respectively, while the (104) lattice spacing of Cu₂S disappeared. After 45 hours of electrolysis, the lattice spacings corresponding to the (204) plane of Cu₂S and the (111) plane of Cu (PDF: 04-0836) were still retained. The results indicate that with the extension of electrolysis time, the lattice spacing of GDY-Al-Cu₂S… v The transformation of the Cu2S crystal plane from (104) to (204) in the electrolysis process shows that the Cu2S (204) crystal plane plays a catalytic role. The morphology of the catalyst changes, which may be due to the partial reduction of Cu2S to Cu in the early stage as the electrolysis time increases, accompanied by a small amount of S leaching. This is also the main reason for the decrease in FE in the early stability test.

[0101] Figure 19 Figure a shows the GDY-Al-Cu2S after stability testing. v HRTEM image, EDS plot ( Figure 19 b) This further confirms that substances such as Cu, Al, S, and C are present in GDY-Al-Cu2S v Uniformly distributed in the middle. XRD patterns of electrolysis at different times ( Figure 20 This indicates that after 0.5 hours of electrolysis, GDY-Al-Cu2S... v The (104) crystal plane of Cu2S disappeared, and the (204) crystal plane became dominant, accompanied by the appearance of a small amount of Cu. With the increase of electrolysis time, the (204) of Cu2S remained stable, and the amount of Cu reduced also increased, which is consistent with the analysis results of HRTEM.

[0102] Figure 21 a shows GDY-Al-Cu2S vThe in-situ XANES spectrum of GDY-Al-Cu2S shows that, with increasing negative potential, the... v The absorption edge moves towards the Cu foil. EXAFS ( Figure 21 b) shows that GDY-Al-Cu2S increases with the applied negative potential. v The bonding strength of the Cu-S bond decreases slightly, while the Cu-Cu bond appears.

[0103] Next, the electrolyzed GDY-Al-Cu2S v and Al-Cu2S v Perform EPR testing, such as Figure 22 As shown, the catalyst still retains a certain amount of S vacancies (g = 2.003) after electrolysis, indicating that the catalyst can also ensure the exposure of more active sites during electrolysis and ensure sufficient CO2 adsorption, so that the subsequent CO2RR can proceed smoothly, thus exhibiting excellent catalytic performance.

[0104] Mechanism characterization

[0105] First, using the same method as preparing the working electrode, the catalyst is coated onto carbon paper. Then, the contact angle between the water droplet and the electrode surface is measured. Figure 23 As shown in a–f, the contact angles of the six catalysts were 158°, 155°, 135°, 132°, 128°, and 125°, respectively. Among them, GDY-Al-Cu2S… v The largest contact angle indicates that GDY-Al-Cu2S v Excellent hydrophobicity helps to suppress the hydrogen evolution reaction, thus promoting the formation of carbon products in CO2RR.

[0106] Electrochemical active surface area (ECSA) is one of the indicators for evaluating the electrochemical performance of catalysts. To further explore the CO2RR nature of catalysts, such as... Figure 24 As shown in figures a–e, CV tests were performed on five doped catalyst samples within the non-Radidatic efficiency range, and the C values ​​were compared. dl Numerical values. CV was measured in a CO2-saturated 0.5M KHCO3 electrolyte, with a scan rate range of 0.1–0.2 V vs. RHE and a scan rate of 20–120 mV s. -1 Within the interval, at a potential of 0.15V vs. RHE, the average current at each sweep rate is fitted and calculated, and the slope of the resulting straight line is C. dl ( Figure 24 f). C of five catalysts dl They are GDY-Al-Cu2S v 144mF cm -2 Al-Cu2Sv 106mF cm -2 Al-Cu2S: 105mF cm -2 In-Cu2S: 44mF cm -2 Ga-Cu2S: 33mFcm -2 The results showed that GDY-Al-Cu2S v With the largest C dl This indicates that it can expose more available active sites, which is beneficial for CO2RR.

[0107] We systematically studied the charge transfer efficiency in the electrocatalytic process using electrochemical impedance spectroscopy. The Nyquist plots of six catalysts are shown below. Figure 25 As shown. Compared with other comparative catalysts, GDY-Al-Cu2S v The small semi-circular radius exhibited in the high-frequency region reflects a low charge transfer resistance at the catalyst / electrolyte interface, which is more conducive to promoting electron transport processes. This relatively low electrode impedance is characteristic of GDY-Al-Cu2S. v One of the key factors contributing to the excellent CO2RR performance of catalysts.

[0108] In alkaline solution, the dissociation of H₂O is a slow step in the HER process. It is assumed that H₂O acts as a hydrogen donor in the alkaline medium during CO₂RR. To understand the role of H₂O dissociation in C₂ product formation, we measured GDY-Al-Cu₂S… v and Al-Cu2S v Kinetic Isotope Effect (KIE) of H / D on Catalysts Figure 26 H / D's KIE is defined as FE. C2H4 The ratio of H₂O to D₂O. The known H / D KIE value represents the dissociation kinetics of H₂O. A KIE value greater than 1.5 indicates that water activation affects the reaction rate. When D₂O is used instead of H₂O as the solvent in a 1M KOH electrolyte, GDY-Al-Cu₂S v The displayed KIE value of 0.5 is less than the KIE value of Al-Cu2S (1.1), indicating that GDY-Al-Cu2S... v The dissociation rate of H2O in GDY-Al-Cu2S is relatively fast. v It can accelerate the dissociation of H2O into * H provides additional sites, indicating that GDY-Al-Cu2S v Mediated local surface *H₂O coverage favors ethanol production. Furthermore, both have KIE values ​​below 2, meaning that the kinetics of H₂O dissociation do not limit the CO₂RR rate.

[0109] To further investigate the CO2RR reaction mechanism of the catalyst, in-situ ATR-FTIR spectroscopy was employed in a CO2-saturated 0.5 M KHCO3 electrolyte system. During the experiment, infrared spectral signals were acquired after 50 seconds of continuous electrolysis under different applied potentials. Figure 27 From a and b, we can see that at 2425cm -1 There is a distinct peak at this point, which belongs to * CO2, representing the adsorbed active CO2 molecules, indicates that both catalysts have a strong adsorption capacity for CO2. At 2064.4 cm⁻¹ -1 and 1303cm -1 Observed at the place * CO atop and * COCO adsorption peak. As can be seen from the figure, with increasing potential, GDY-Al-Cu2S... v of * CO atop The intensity increases accordingly, and the peak intensity is lower than that of Al-Cu2S. v This indicates that in GDY-Al-Cu2S v superior * CO has a lower binding energy, which is beneficial for subsequent CC coupling. * COCO. At 1575.4 and 1179cm -1 It can be seen from the observation * COCOH and * The OC2H5 intermediate, as shown in the figure, exhibits a gradual decrease in peak values ​​for both intermediates as the potential increases, demonstrating the consumption of these two intermediates during the CO2RR process. This explains the formation of ethylene and ethanol in the products. Simultaneously, different times at -1.5V vs. RHE potentials (…) Figure 27 c) and d) also show the corresponding peak positions, and it can be seen that * COCOH and * The amount of OC2H5 intermediate increases with time. It is assumed that electron-deficient Al... 3+ Ion doping can suppress the generation of H2 and Cl, and enhance... * CO dimerization improves selectivity for C2 products.

[0110] Figure 28 Figures a and b show that GDY-Al-Cu2S v and Al-Cu2S v middle * CO atopThe high-frequency band (HFB) and low-frequency band (LFB) of the peak, and the peak area ratio at different potentials. Although both sites can promote * CO dimerizes to produce C2 products, but Cu atoms with lower coordination numbers... * CO exhibits a strong adsorption capacity; clearly, at higher potentials, GDY-Al-Cu2S... v On the surface * CO atop The HFB / LFB ratio is much higher than that of Al-Cu2S. v ( Figure 28 c). These results indicate that GDY-Al-Cu2S v The catalyst has a greater number of step sites, which promotes more effectively * The dimerization of CO promotes the production of multi-carbon products. Figure 28 c represents the two catalysts at different potentials. * A comparison of the peak area and intensity of the OC2H5 intermediate is shown in the figure. (GDY-Al-Cu2S) v middle * The peak value of OC2H5 is higher than that of Al-Cu2S. v This indicates that GDY loading promotes charge transfer in the electrocatalytic CO2RR process, and the key intermediate in ethanol production is GDY-Al-Cu2S. v More stable on FE C2 Under comparable conditions, the FE of ethanol is increased. After Al doping, Al-induced electrons transfer from Cu to Al, as can be seen from the XPS image. 1+ / Cu 0 An increase in the ratio causes a positive shift in the oxidation state of Cu, which is beneficial. * CO coupling * The free energy of CO2 promotes the formation of C2 products. Furthermore, ion vacancies have been shown to promote CO2 activation and... * A type of catalytic site for C1 adsorption to generate C≤2 products. S vacancies can cause electrons from surrounding Cu to migrate to the vacancy (reactive site), causing the oxidation state of Cu to shift positively again, thus enhancing the selectivity and activity of the CO2RR process.

[0111] Linear sweep voltammetry for electrochemical CO dissolution (at 50 mV s) -1 Record, Figure 29 In GDY-Al-Cu2S, the peak near 0.8±0.9 V corresponds to the CO dissolution process. v The CO dissolution peak area is significantly larger than that of Al-Cu2S. v The CO dissolution peak area. Because the CO stripping peak area and...* The surface coverage of CO is related to GDY-Al-Cu2S v Increased * The increased surface coverage of CO promotes CC coupling. In summary, the GDY loading and increased vacancies modulate the electronic structure of Cu, enhancing CO2 adsorption capacity and increasing surface CO coverage. These combined effects may contribute to improving the performance of GDY-Al-Cu2S… v Activity and selectivity of electrocatalytic CO2RR to C2.

[0112] In addition, at 280cm -1 and 360cm -1 Two different Raman peaks were observed at this location. Figure 30 a) and b) correspond to the confined rotation (P1) and Cu-CO stretching (P2) vibrations of adsorbed CO. The ratio of P2 / P1 peak intensity is used to evaluate... * An effective measure of the surface coverage of CO on the catalyst. With * Increased CO coverage, two * The dimerization barrier of CO molecules can be effectively lowered. This is particularly true for GDY-Al-Cu2S... v and Al-Cu2S v Quantitative analysis of the Raman peaks of GDY-Al-Cu2S under different applied potentials v The P2 / P1 ratio of the catalyst is significantly increased. Figure 31 This demonstrates that the loading and coordination of GDY and the increase of vacancies can regulate the catalyst and improve the CO loading in GDY-Al-Cu2S. v Surface coverage on the catalyst. These results collectively demonstrate that the addition of GDY can modulate... * The adsorption sites and coverage of CO intermediates on Cu-based catalysts and their derivatives contribute to enhancing the selective formation of C2 products.

[0113] To elucidate the interaction between GDY and the metal catalyst, GDY-Al-Cu2S v and Al-Cu2S v The electrolytically stabilized Cu2S(204) surface was used as the basis for the computational model. Figure 32 (a and b).

[0114] Figure 33 a shows GDY-Al-Cu2S v and Al-Cu2S v The reaction energy diagrams for the conversion of CO2 to ethanol and ethylene on Cu2S(204) catalysts simulated by two catalysts show that the loading of GDY effectively reduces the binding energy of the CC coupling, promoting the CO2RR to C2 products. *Starting with the watershed intermediate CH2CHO, then hydrogenation and deoxygenation are used to produce... * CH2CH2 (ethylene pathway) or hydrogenation due to the breaking of Cu-C and Cu-O bonds produces * CH3CHO (ethanol pathway). Free energy diagram shows GDY-Al-Cu2S v middle * CH2CHO * The reaction energy of CH2CH2 is higher than that of CH2CH2. * CH2CHO * The reaction energy of CH3CHO indicates that GDY-Al-Cu2S v The catalyst CO2RR exhibits high selectivity for C2H5OH. For example... Figure 33 b shows GDY-Al-Cu2S v and Al-Cu2S v The free energy diagrams for water dissociation of the two catalysts show that GDY-Al-Cu2S v The energy required to dissociate water is lower than that required for Al-Cu2S. v This indicates that GDY-Al-Cu2S v The ability to donate protons to CO2RR is higher than that of Al-Cu2S. v This is consistent with the results obtained by KIE.

[0115] Considering * The key role of CH2CHO in the selectivity of ethanol and ethylene was simulated. * The projected density of states (PDOS) of Cu 3d orbitals adsorbed by CH2CHO is used to elucidate adsorbate-adsorbate interactions. For example... Figure 34 As shown in a, GDY-Al-Cu2S v It exhibits higher electron occupation near the Fermi level, which means that after adding GDY, it is comparable to * The interaction with the CH2CHO intermediate is stronger. Subsequently, the Al-Cu2S... v and GDY-Al-Cu2S v Surface adsorption * PDOS of the O 2p and C 2p orbitals of CH2CHO were used to elucidate the CO binding state. In GDY-Al-Cu2S v The more significant overlap reveals stronger CO bond binding, which implies suppression of CO bond breaking to produce ethylene, thereby enhancing the reaction preference for ethanol production. Figure 34 b). The Hamiltonian population (p) of the projected crystal orbitals was calculated. COHP ), to directly clarify * The strength of the CO bond in CH2CHO ( Figure 34 c). GDY-Al-Cu2Sv p COHP The integral value (ICOHP) is greater than that of Al-Cu2S. v The negative result confirms that the loading of GDY can enhance the strength of the CO bond.

[0116] Finally, Bader charge analysis was performed to quantify the charge. * The Cu-C and Cu-O bonds in CH2CHO break, forming... * Charge transfer changes in CH3CHO. (In GDY-Al-Cu2S) v The charge transfer changes observed during the breaking of Cu-C and Cu-O bonds were relatively small (0.19|e|). Figure 35 The results indicate that weaker Cu-C and Cu-O bond strengths favor the conversion of CO2 to ethanol. Overall, these results suggest that the addition of GDY can enhance... * The CO bond in CH2CHO weakens both the Cu-C and Cu-O bonds, thus favoring the conversion of CO2 into ethanol.

[0117] This application describes the in-situ preparation of Al-doped Cu₂S nanomaterials with sulfur vacancies on a GDY substrate. The morphology and structure of the material were tested using various characterization methods. Subsequent performance tests and theoretical calculations indicate that, due to the unique structure of graphdiyne and its synergistic effect with copper, GDY-Al-Cu₂S… v The material exhibits a significant selectivity for C2H5OH; at a potential of -1.5V vs. RHE, its FE C2H5OH It was 58.4%, FE C2 The percentage reached 77%, with FE (electron-deficient ferrite) in carbon-containing products exceeding 90%. This was influenced by the regulation of GDY, the increase of vacancies, and the electron-deficient Al... 3+ Regulation enhances the catalyst's resistance to... * The increased CO coverage simultaneously lowers the energy barrier for CC coupling, promoting subsequent CC coupling. * COCO, thereby improving the selectivity of CO2RR to the target product. Finally, GDY-Al-Cu2S v Catalyst at 500 mA cm -2 Stability tests were conducted at the specified current density, and it remained stable for 45 hours under electrolysis. C2 At over 70%, FE C2H5OH Maintaining a content above 55%. This application provides a new strategy for designing and synthesizing copper-based nanomaterials for highly efficient electrocatalytic CO2RR.

[0118] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing graphdiyne-supported doped copper-based nano-electrocatalysts, characterized in that: The steps include: under a protective gas atmosphere, CuCl, Al(NO3)3·9H2O, CH4N2S, graphyne, and solvent are mixed and stirred, and 1-butyl-3-methylimidazolium tetrafluoroborate is gradually added dropwise to obtain a mixed solution; The mixed solution was heated, cooled to room temperature, washed and dried to obtain a graphdiyne-supported doped copper-based nanocatalyst.

2. The method for preparing the graphdiyne-supported doped copper-based nano-electrocatalyst according to claim 1, characterized in that: The molar ratio of CuCl, Al(NO3)3·9H2O, and CH4N2S is 1:0.9-1.1:0.9-1.

1.

3. The method for preparing the graphdiyne-supported doped copper-based nano-electrocatalyst according to claim 1, characterized in that: Solvents include deionized water and isopropanol; And / or, the protective gas includes one of nitrogen, helium, argon, neon, krypton, and xenon; And / or, the volume ratio of deionized water to isopropanol is 1:3.8-4.2; And / or, the mixing time is 4-6 minutes.

4. The method for preparing the graphdiyne-supported doped copper-based nano-electrocatalyst according to claim 1, characterized in that: The heating temperature of the mixed solution is 55-65℃, and the heating time is 2.5-3.5h.

5. The method for preparing the graphdiyne-supported doped copper-based nano-electrocatalyst according to claim 1, characterized in that: The washing and drying process includes washing multiple times with a mixture of deionized water and ethanol, followed by vacuum drying at a temperature of 55-65℃ for 22-26 hours. The volume ratio of the deionized water and ethanol mixture is 1:0.8-1.

2.

6. The method for preparing the graphdiyne-supported doped copper-based nano-electrocatalyst according to claim 1, characterized in that: The preparation of graphyne includes the following steps: hexa(trimethylsilylethynyl)benzene, CuCl and N,N-dimethylformamide are mixed, sealed and heated to 55-65℃ for 22-26 h. After the reaction is completed, CuO / GDY is obtained. CuO / GDY is washed successively with N,N-dimethylformamide, dichloromethane, tetrahydrofuran and methanol. The washed sample is etched by adding HCl and then post-treated to obtain graphyne.

7. The method for preparing the graphdiyne-supported doped copper-based nano-electrocatalyst according to claim 1, characterized in that: Post-processing included washing the sample twice with deionized water, then once with acetone, centrifuging, and air-drying in a ventilated place to obtain graphylene.

8. The graphyne-supported doped copper-based nano-electrocatalyst prepared by the method of any one of claims 1-7.

9. The graphyne-supported doped copper-based nano-electrocatalyst prepared by the method according to any one of claims 1-7 can be applied to the utilization of CO2 resources.

Images