Surface Engineering on Commercial Cu Foil for Steering C 2 H 4 /CH 4 Ratio in CO 2 Electroreduction.

Designing catalysts with high selectivity toward C 2 products in CO 2 electroreduction is crucial to energy storage and sustainable development. Here, we propose a Cu foil kinetic model with abundant nanocavities possessing higher reaction rate constant k to steer the ratio of C 2 H 4 to the competing CH 4 during CO 2 electroreduction. Chemical kinetic simulation demonstrates that the nanocavities could enrich the adsorbed CO surface concentration (θ COad ), while the higher k helps to lower the C-C coupling barrier for CO intermediates, thus favoring the formation of C 2 H 4 . The commercial Cu foil treated with cyclic voltammetry is used to match this model, displaying a remarkable C 2 H 4 /CH 4 ratio of 4.11, which is 18 times larger than that on the pristine Cu foil. This work offers a handy strategy for surface modification and provides new insights into the C-C coupling and the C 2 H 4 selectivity in terms of mass transfer flux and energy barrier.