Atomic-scale surface restructuring of copper electrodes under CO2 electroreduction conditions

Abstract Potentiodynamic methods that induce structural changes in Cu catalysts for the electrochemical reduction of CO 2 (CO RR) have been identified as a promising strategy steering catalyst selectivity towards generation multi-carbon products. In current approaches, active species are created via sequential oxidation–reduction process. Here we show by situ scanning tunnelling microscopy, surface X-ray diffraction and Raman spectroscopy measurements low-coordinated form spontaneously near onset electrocatalytic reduction. This process starts CO-induced nanocluster formation initial stages reaction, leading to irreversible restructuring persists over wide potential range. On subsequent increase, nanoclusters disperse into adatoms, which stabilize reaction intermediates on surface. The observed self-induced undercoordinated sites -converting can account its reactivity may be exploited (re)generate RR potentiodynamic protocols.