Cu metal embedded in oxidized matrix catalyst to promote CO2 activation and CO dimerization for electrochemical reduction of CO2.

We propose and validate with quantum mechanics methods a unique catalyst for electrochemical reduction of CO2 (CO2RR) in which selectivity and activity of CO and C2 products are both enhanced at the borders of oxidized and metallic surface regions. This Cu metal embedded in oxidized matrix (MEOM) catalyst is consistent with observations that Cu2O-based electrodes improve performance. However, we show that a fully oxidized matrix (FOM) model would not explain the experimentally observed performance boost, and we show that the FOM is not stable under CO2 reduction conditions. This electrostatic tension between the Cu+ and Cu0 surface sites responsible for the MEOM mechanism suggests a unique strategy for designing more efficient and selective electrocatalysts for CO2RR to valuable chemicals (HCOx), a critical need for practical environmental and energy applications.