Active site identification and engineering during the dynamic evolution of copper-based catalysts for electrocatalytic CO2 reduction

To date, copper-based catalysts are one of the most prominent catalysts that can electrochemically reduce CO2 towards high-value fuels or chemicals, such as ethylene, ethanol, acetic acid. However, the chemically active feature of Cu-based catalysts hinders the understanding of the intrinsic catalytic active sites during the initial and the operative processes of electrochemical CO2 reduction (CO2RR). The identification and engineering of active sites during the dynamic evolution of catalysts are thereby vital to further improve the activity, selectivity, and durability of Cu-based catalysts for high-performance CO2RR. In this regard, four triggers for the dynamic evolution of catalysts were introduced in detail. Afterward, three typical active-site theories during the dynamic reconstruction of catalysts were discussed. In addition, the strategies in catalyst design were summarized according to the latest reports of Cu-based catalysts for CO2RR, including the tuning of electronic structure, controlling of the external potential, and regulation of local catalytic environment. Finally, the conclusions and perspectives were provided to inspire more investigations and studies on the intrinsic active sites during the dynamic evolution of catalysts, which could promote the optimization of the catalyst system to further improve the performance of CO2RR.