Effect of crystal defects on the electrocatalytic CO2 reduction performance of pure copper

Abstract

Cu-based materials are promising electrochemical catalysts for CO₂ reduction reaction (CO₂RR) to synthesize various products of hydrocarbons and oxygenates. Crystal defects including vacancies, dislocations, grain boundaries can basically control the product selectivity of CO₂RR. However, experimental evidence is lacking on the impact of crystal defects on the electrocatalytic CO₂RR performance of bulk Cu-based alloys. In this study, 10 mm diameter pure Cu discs with carefully engineered dislocations, grain boundaries are prepared through high-pressure torsion (HPT) combined with annealing treatment, and the effect of crystal defects on electrocatalytic CO₂RR performance is systematically studied. Compared with Cu discs with a small number of grain boundaries and a large number of dislocations, Cu discs with a large number of grain boundaries and a low density of dislocations show much better CO₂RR performances, especially in terms of the generation of CO and high-value products such as C₂H₄.