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

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. © 2024 Acta Materialia Inc.