Selective C <sub>2</sub> Electroproduction via Back Bonding in Asymmetric Copper‐Copper Motifs
Chenchen Fang, Liming Dai, Xiaoyuan Zhang, Zhuolun Li, Yaya Wang, Xuefeng Xu, Shuo San, Kai Liu, Yuchen Fu, Junjie Cui, Jianfei Che, Pan Xiong, Yongsheng Fu, Jingwen Sun, Junwu Zhu
Abstract
Abstract CO 2 reduction reaction (CO 2 RR) is considered a highly attractive approach to reduce carbon emissions and yet encounters challenges in further converting *C 1 intermediates to valuable two‐carbon (C 2 ) products. Although copper‐based catalysts exhibit satisfactory adsorption energy for *C 1 species, the symmetrical charge distribution at adjacent copper sites leads to a strong repulsive force between adsorbed *C 1 . Herein, asymmetric copper‐copper (Cu F ‐Cu N ) motifs with distinct adsorption behaviors have been constructed on the F‐Cu 3 N substrate using the in situ isostructural substitution method. Compared to the high hybridization of Cu N 3d and N 2p orbitals, implanted F not only reduces the hybridization strength but also endows the Cu F with delocalized unpaired electrons. Accordingly, Cu F , beyond forming an isolated 3d z 2 ‐2p z σ bond between Cu and the key *C 1 intermediate (*CHO), offers additional 3d xz ‐2p z π back bonding to the *CHO. With dipole interactions in the asymmetric Cu F ‐Cu N motifs, the electrostatic repulsion between adjacent *CHO is diminished, efficiently promoting the C‐C coupling in CO 2 RR. Therefore, the Cu F ‐Cu N motifs achieve an exceptional C 2 selectivity of 81.5% with a partial current density of −325.9 mA cm −2 and a C 2 /C 1 selectivity ratio of 10.47. This nuanced manipulation of atomic interactions illuminates a path to potentially groundbreaking alterations in material characteristics.