title: Oxygen-induced changes to selectivity-determining steps in electrocatalytic CO2 reduction.
abstract: The state of the electrocatalyst surface-including the oxidation state of the catalyst and the presence of spectator species-is investigated on Cu surfaces with density functional theory in order to understand predicted ramifications on the selectivity and efficiency of CO2 reduction. We examined the presence of oxygen-based species, including the fully oxidized Cu2O surface, the partially oxidized Cu(110)-(2 × 1)O surface, and the presence of OH spectators. The relative oxygen binding strength among these surfaces can help to explain the experimentally observed selectivity change between CH4 and CH3OH on these electrodes; this suggests that the oxygen-binding strength may be a key parameter which predicts the thermodynamically preferred selectivity for pathways proceeding through a methoxy (CH3O) intermediate. This study shows the importance of the local surface environment in the product selectivity of electrocatalysis, and suggests a simple descriptor that can aid in the design of improved electrocatalytic materials.
authors.affiliation: Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
authors.forename: Yin-Jia
authors.initials: YJ
authors.lastname: Zhang
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Peterson