Cu metal embedded in oxidized matrix catalyst to promote CO 2 activation and CO dimerization for electrochemical reduction of CO 2

Significance A most promising approach to boosting both efficiency and selectivity for electrochemical reduction of CO 2 (CO 2 RR) is using Cu 2 O-based electrodes, and the surface Cu + is believed to play an essential role that is totally unclear from both experiment and theory. We find that the surface Cu + by itself actually deteriorates the performance of CO 2 RR. Instead we propose a Cu metal embedded in oxidized matrix (MEOM) model and show that it is synergy between surface Cu + and surface Cu 0 present in the MEOM model that improves significantly the kinetics and thermodynamics of both CO 2 activation and CO dimerization, thereby boosting the efficiency and selectivity of CO 2 RR. The MEOM model serves as a unique platform for design of better electrocatalysts for CO 2 RR.