Predesign of Catalytically Active Sites via Stable Coordination Cluster Model System for Electroreduction of CO2 to Ethylene

Abstract Purposefully designing the well‐defined catalysts for the selective electroreduction of CO 2 to C 2 H 4 is an extremely important but challenging work. In this work, three crystalline trinuclear copper clusters ( Cu 3 ‐X , X=Cl − , Br − , NO 3 − ) have been designed, containing three active Cu sites with the identical coordination environment and appropriate spatial distance, delivering high selectivity for the electrocatalytic reduction of CO 2 to C 2 H 4 . The highest faradaic efficiency of Cu 3 ‐X for CO 2 ‐to‐C 2 H 4 conversion can be adjusted from 31.90 % to 55.01 % by simply replacing the counter anions (NO 3 − , Cl − , Br − ). The DFT calculation results verify that Cu 3 ‐X can facilitate the C−C coupling of identical *CHO intermediates, subsequently forming molecular symmetrical C 2 H 4 product. This work provides an important molecular model system and a new design perspective for electroreduction of CO 2 to C 2 products with symmetrical molecular structure.