Theory-Guided Modification of Ionic Liquid on Cu<sub>2</sub>O Promotes Asymmetric C–C Coupling for CO<sub>2</sub> Conversion
Shilun Wang, Wei Peng, Heliang Ma, Xingdi Pan, Yao Shen, Jingkai Zhao, Jiexu Ye, Qiaoli Wang, Pengfei Xie, Shihan Zhang, Xiang Gao
Abstract
The electrocatalytic reduction of carbon dioxide (CO 2 RR) by copper oxide-based materials is conducive to the formation of high value-added products, but their activities and selectivities remain unsatisfactory. Organic ligand modification is a promising strategy to achieve a high CO 2 RR activity. Here, the modification of Cu 2 O with 1-butyl-3-methylimidazolium chloride (Bmim-Cu 2 O) enhanced the adsorption of reaction intermediates and improved the stability of the catalyst in the CO 2 RR, which displays a high Faradaic efficiency of ≈85% to C 2+ products with a current density as large as ≈352.5 mA cm –2 . In situ characterization reveals a stronger *CO signal with bridge configuration and a stronger *OCCHO signal over Bmim-Cu 2 O than unmodified Cu 2 O and can improve the stability during electrochemical CO 2 reduction. Density functional theory calculations show that local molecular modulation can effectively regulate the electronic structure of Cu 2 O and enhance the adsorption of *CO and *CHO intermediates through the stabilization of a noncovalent interaction, which can greatly promote the asymmetric *CO–*CHO coupling in the electrochemical reaction process.