Modulation of the Coordination Environment of Copper for Stable CO₂ Electroreduction with Tunable Selectivity

Manipulating the product selectivity of an electrochemical CO₂ reduction reaction (CO₂RR) is challenging due to the unclear and uncontrollable active sites. Here, we report stable CO₂RR operation with tunable product selectivity over a family of molecule-modulated copper catalysts. The coordination environment of Cu in catalysts is modulated by an imidazole-based molecule via different synthetic routes. Various carbonaceous products ranging from carbon monoxide, methane, and ethylene were selectively produced via, respectively, tuning the coordination environment of copper atoms from Cu-N, Cu-C, and Cu-Cu. Density functional theory (DFT) calculations reveal that the Cu-N sites weaken the adsorption energy of the *CO intermediate, which is beneficial for CO desorption. The Cu-C and Cu-Cu sites, respectively, facilitate the formation of *OCOH and *(CO)₂ intermediates, favoring the CH₄ and C₂H₄ pathways. This work provides a stable and simple model system for studying the influence of coordination elements on the product selectivity of CO₂RR.