Nanoporous carbons for the electrochemical reduction of CO2: Challenges to discriminate the roles of nanopore confinement and functionalization

Abstract

The use of porous carbons in the electrochemical reduction of CO2 (CO2ER) has become an active research area. Despite good faradaic efficiencies and production rates, understanding their electrocatalytic activity is challenging owing to the complexity of the CO2-nanoporous carbon interactions. In this opinion review, we emphasize on the critical importance of discriminating the impacts of nanopore confinement and surface functionalization of porous carbons on the CO2ER. We have performed a rational analysis of recent literature addressing this topic, comparing electrocatalytic performance with knowledge about CO2-porous carbon affinity. Reported data have been re-discussed focusing on a complete characterization of the carbon electrodes to correlate physicochemical characteristics and the electrocatalytic activity. A perspective view is provided for future directions on the use of porous carbons in the CO2ER.