CO<sub>2</sub> Reduction on Copper’s Twin Boundary
Can Tang, Jianjian Shi, Xiaowan Bai, Anqi Hu, Ningning Xuan, Yawei Yue, Tong Ye, Bing Liu, Pengxiang Li, Peiyuan Zhuang, Jianfeng Shen, Yuanyue Liu, Zhengzong Sun
Abstract
Electrocatalysts are evolving toward chemically tunable atomic structures, among which the catalyst engineering from a defect perspective represents one of the mainstream technical genres. However, most defects cannot be purified or their numbers gauged, making them too complex to explore the hidden catalytic mechanism. A twin boundary, with well-defined symmetric structure and high electrocatalytic activity, is an elegant one-dimensional model catalyst in pursuing such studies. Here on polished Cu electrodes, we successfully synthesized a series of copper twin boundaries, whose density ranges from 0 to 105 cm–1. The CH4 turnover frequency on the twin boundary atoms is 3 orders higher than that on the plane atoms, and the local partial current density reaches 1294 mA cm–2, with an intrinsic Faradaic efficiency of 92%. An intermediate experiment and density functional theory studies confirm the twin boundary’s advantage in converting the absorbed CO* into CH4.