Design Regulation And Performance Study Of Metal Oxide Carbon Dioxide Electrocatalytic Materials

Carbon dioxide reduction reaction（CO₂RR）is considered to be a promising method for reducing atmospheric CO₂ concentration in the future.At present,the commercial CO₂RR electrocatalyst are precious metal catalysts.However,high cost,limited reserves,and poor stability hinder the widespread application of precious metal-based electrocatalysts.Therefore,the design of high-efficiency non-precious metal-based electrocatalysts and the improvement of electrolytic cell equipment have become research hotspots.Metal oxides have received increasing attention due to their high selectivity to C1 products（CO and HCOOH）and are considered as promising CO₂RR catalysts.Therefore,in this paper,the non-precious metal oxides zinc oxide and indium oxide,which can generate different C1 products,are used as the research objects for modification research.We are committed to studying the structure-activity relationship between the construction of metal oxides construction of metal oxides/carbon composite and CO₂RR performance to prepare efficient and stable electrocatalysts.In the first part of this work,by constructing a metal oxide doping defect strategy,heteroatom（Mo,Cu）doping into Zn O to replace Zn sites was achieved.Among them,Zn O doped by Mo atoms（Mo-Zn O）has excellent CO₂RR performance,the CO current density reaches-6.89 m A cm^-2 at-1.0 V vs.RHE,and the stability is good,far exceeding that of commercial Pd/C.The reason why Mo-Zn O has a high CO₂RR catalytic activity is that the doping of Mo can effectively build metal oxide defects,thereby changing the adsorption capacity of the material itself to reaction intermediates,and ultimately affecting CO₂RR and ultimately changing CO₂RR and the competitive hydrogen evolution reaction（HER）process,the energy barrier of CO₂RR reaction is lowered,and the energy barrier of HER reaction is increased,which promotes the improvement of CO₂RR performance.In the second part of this work,by constructing a metal oxide/carbon composite interface strategy,nitrogen-doped carbon shell-wrapped indium oxide（In₂O₃（?）NC@GO）was prepared.In₂O₃（?）NC@GO exhibits excellent CO₂RR performance,with HCOO^-current density reaching-40.38 m A cm^-2 at-0.8 V vs.RHE,and excellent stability.The reasons for the higher CO₂RR activity of In₂O₃（?）NC@GO benefit from the multi-component synergy:1)Due to the confinement effect of the amorphous N-doped carbon shell,the particle size and dispersion of In₂O₃ nanoparticles are optimized,exposing Active sites for more electrochemical reactions.2)There are a large number of oxygen vacancies in In₂O₃,which enhances the adsorption and activation ability of CO₂.3)The nitrogen-doped carbon shell can prevent the direct contact between the active site and the electrolyte,thereby significantly suppressing the HER reaction.4)The charge transfer in CO₂RR is also effectively enhanced due to the presence of carbon components.