Design strategies for particle catalysts used in electrocatalytic CO2 reduction in acidic media
LI Xiaopeng
HU Weibo
Abstract：Significance To review the design strategies for metal particle catalysts used in the electrocatalytic CO2 reduction reaction(eCO2RR)in acidic media and to support further development of acidic eCO2RR research.
Progress This review summarizes recent reports on the structural design methods of catalyst particles for acidic eCO2RR.The cur-rent design methods for metal catalysts used in acidic eCO2RR can be broadly categorized into organic modification,bimetallic cataly-sis,non-metal element doping,inorganic layer modification,and morphology control.The increased concentration of H+in acidic electrolytes raises the surface-adsorbed H+(*H)ratio on the electrode,enhancing hydrogen evolution reaction(HER)kinetics,which in turn leads to poor product selectivity and low activity in acidic eCO2RR.Reducing the local H+concentration on the elec-trode surface or increasing the adsorption selectivity of the electrode material for CO2 and intermediates are potential methods for pro-moting acidic eCO2RR.
Conclusions and Prospects In 2021,acidic eCO2RR was first proposed.Over the past few years,some catalysts have achieved high product selectivity in acidic eCO2RR,yet significant challenges remain:1)A method that simultaneously achieves high selectivity,high reaction rates,and high stability in acidic eCO2RR is still lacking.Current designs for acidic catalysts often rely on alkali metal ions(e.g.,K+)to suppress HER and activate CO2.However,these designs typically require the addition of high concentrations of alkali metal salts,which can lead to salt deposition,impairing gas diffusion and catalytic stability.Additionally,non-precious metal catalysts tend to dissolve in acidic media,resulting in active site loss.Encapsulating the exterior of metal particles with suitable organic or inorganic layers can improve catalytic stability to some extent but may block active sites,thereby reducing the conversion rate.2)The selectivity for single multi-electron transfer products in acidic eCO2RR needs improvement.While some catalysts exhibit high selectivity for acidic eCO2RR products,these products are primarily limited to CO,formic acid,and mixed C2+products(e.g.,ethanol,acetic acid,ethylene,and propanol).The selectivity for single multi-electron transfer products,such as ethylene,ethanol,or acetic acid,is much lower in acidic eCO2RR compared to neutral or alkaline eCO2RR.The formation mechanisms of multi-electron transfer products in acidic eCO2RR may differ from those in neutral or alkaline eCO2RR and require further exploration and elucidation.3)Despite numerous studies on catalyst particles with excellent eCO2RR performance in recent years,most catalysts have the disadvantages of complex synthesis processes,limited production scalability,and inconsistent performance reproducibil-ity.Developing efficient,easy-to-operate,and scalable synthesis methods for catalysts is a critical step toward the industrial applica-tion of eCO2RR.4)Improvements in eCO2RR electrolyzers are urgently needed.In addition to developing high-performance cata-lysts that can be produced at scale,advancements in electrolyzer design and technology are equally important for the practical applica-tion of eCO2RR.
Keywords：electrocatalytic CO2 reduction reactionacidic mediasurface microenvironmentelectronic structurecatalyst design
Publication Date：2025-03-01
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：10( 81-90 )