Steering the Site Distance of Atomic Cu−Cu Pairs by First‐Shell Halogen Coordination Boosts CO<sub>2</sub>‐to‐C<sub>2</sub> Selectivity
Fengya Ma, Pengfang Zhang, Xiaobo Zheng, Liang Chen, Yunrui Li, Zechao Zhuang, Yameng Fan, Peng Jiang, Hui Zhao, Jiawei Zhang, Yuming Dong, Yongfa Zhu, Dingsheng Wang, Yao Wang
Abstract
Abstract Electrocatalytic reduction of CO 2 into C 2 products of high economic value provides a promising strategy to realize resourceful CO 2 utilization. Rational design and construct dual sites to realize the CO protonation and C−C coupling to unravel their structure‐performance correlation is of great significance in catalysing electrochemical CO 2 reduction reactions. Herein, Cu−Cu dual sites with different site distance coordinated by halogen at the first‐shell are constructed and shows a higher intramolecular electron redispersion and coordination symmetry configurations. The long‐range Cu−Cu (Cu−I−Cu) dual sites show an enhanced Faraday efficiency of C 2 products, up to 74.1 %, and excellent stability. In addition, the linear relationships that the long‐range Cu−Cu dual sites are accelerated to C 2 H 4 generation and short‐range Cu−Cu (Cu−Cl−Cu) dual sites are beneficial for C 2 H 5 OH formation are disclosed. In situ electrochemical attenuated total reflection surface enhanced infrared absorption spectroscopy, in situ Raman and theoretical calculations manifest that long‐range Cu−Cu dual sites can weaken reaction energy barriers of CO hydrogenation and C−C coupling, as well as accelerating deoxygenation of *CH 2 CHO. This study uncovers the exploitation of site‐distance‐dependent electrochemical properties to steer the CO 2 reduction pathway, as well as a potential generic tactic to target C 2 synthesis by constructing the desired Cu−Cu dual sites.