Ligand-tuning copper in coordination polymers for efficient electrochemical C–C coupling
Yu Yang, Cheng Zhang, Chengyi Zhang, Yaohui Shi, Jun Li, Bernt Johannessen, Yongxiang Liang, Shuzhen Zhang, Qiang Song, Haowei Zhang, Jialei Huang, Jingwen Ke, Lei Zhang, Qingqing Song, Jianrong Zeng, Ying Zhang, Zhigang Geng, Pu‐Sheng Wang, Ziyun Wang, Jie Zeng, Fengwang Li, Jie Zeng, Fengwang Li
Abstract
Cu catalyses electrochemical CO2 reduction to valuable multicarbon products but understanding the structure-function relationship has remained elusive due to the active Cu sites being heterogenized and under dynamic re-construction during electrolysis. We herein coordinate Cu with six phenyl-1H-1,2,3-triazole derivatives to form stable coordination polymer catalysts with homogenized, single-site Cu active sites. Electronic structure modelling, X-ray absorption spectroscopy, and ultraviolet–visible spectroscopy show a widely tuneable Cu electronics by modulating the highest occupied molecular orbital energy of ligands. Using CO diffuse reflectance Fourier transform infrared spectroscopy, in-situ Raman spectroscopy, and density functional theory calculations, we find that the binding strength of *CO intermediate is positively correlated to highest occupied molecular orbital energies of the ligands. As a result, we enable a tuning of C–C coupling efficiency—a parameter we define to evaluate the efficiency of C2 production—in a broad range of 0.26 to 0.86. This work establishes a molecular platform that allows for studying structure-function relationships in CO2 electrolysis and devises new catalyst design strategies appliable to other electrocatalysis. Understanding the structure-function relationship in Cu-catalyzed CO2 reduction is challenging due to dynamic active sites. This study introduces stable coordination polymer catalysts with homogenized, single-site Cu, enabling the study and tuning of C–C coupling efficiency in CO2 electroreduction.