Elucidating the Structure of Ethanol-Producing Active Sites at Oxide-Derived Cu Electrocatalysts

Abstract

The discovery of oxide-derived copper catalysts for CO2 electroreduction is an outstanding advance in the field of electrocatalysis. Their low overpotentials and improved selectivity towards C2 products make them unique. However, the structure of the active sites responsible for these improvements remains unclear. Herein, by means of a computational model including thermodynamic, kinetic, solvent and cation effects, we outline the atomic structure of the active sites responsible for ethanol evolution in OD-Cu catalysts. We also point out the specific features that determine selectivity and pinpoint the design criteria that should be fulfilled to enhance the catalysts’ selectivity toward ethanol. Specifically, we propose that square, four-atom Cu islands are the active sites of OD-Cu for CORR to ethanol, as they display favorable *CO dimerization and ethanol selectivity by virtue of their square, undercoordinated structure.