Highly Selective Electrochemical Reduction of CO<sub>2</sub> into Methane on Nanotwinned Cu
Jin Cai, Qing Zhao, Wei-You Hsu, Chungseok Choi, Yang Liu, John Mark P. Martirez, Chih Chen, Jin Huang, Emily A. Carter, Yu Huang
Abstract
High Resolution Image Download MS PowerPoint Slide The electrochemical carbon dioxide reduction reaction (CO 2 RR) is a promising route to close the carbon cycle by reducing CO 2 into valuable fuels and chemicals. Electrocatalysts with high selectivity toward a single product are economically desirable yet challenging to achieve. Herein, we demonstrated a highly (111)-oriented Cu foil electrocatalyst with dense twin boundaries (TB) (tw-Cu) that showed a high Faradaic efficiency of 86.1 ± 5.3% toward CH 4 at −1.2 ± 0.02 V vs the reversible hydrogen electrode. Theoretical studies suggested that tw-Cu can significantly lower the reduction barrier for the rate-determining hydrogenation of CO compared to planar Cu(111) under working conditions, which suppressed the competing C–C coupling, leading to the experimentally observed high CH 4 selectivity.