Surface Engineering on Commercial Cu Foil for Steering C<sub>2</sub>H<sub>4</sub>/CH<sub>4</sub> Ratio in CO<sub>2</sub> Electroreduction
Peiquan Ling, Yinghuan Liu, Zhiqiang Wang, Li Li, Jun Hu, Junfa Zhu, Wensheng Yan, Huijun Jiang, Zhonghuai Hou, Yongfu Sun, Yi Xie
Abstract
Designing catalysts with high selectivity toward C2 products in CO2 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 C2H4 to the competing CH4 during CO2 electroreduction. Chemical kinetic simulation demonstrates that the nanocavities could enrich the adsorbed CO surface concentration (θCOad), while the higher k helps to lower the C–C coupling barrier for CO intermediates, thus favoring the formation of C2H4. The commercial Cu foil treated with cyclic voltammetry is used to match this model, displaying a remarkable C2H4/CH4 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 C2H4 selectivity in terms of mass transfer flux and energy barrier.