Predesign of Catalytically Active Sites via Stable Coordination Cluster Model System for Electroreduction of CO 2 to Ethylene

Purposefully designing the well-defined catalysts for the selective electroreduction of CO2 to C2 H4 is an extremely important but challenging work. In this work, three crystalline trinuclear copper clusters (Cu3 -X, X=Cl- , Br- , NO3- ) 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 CO2 to C2 H4 . The highest faradaic efficiency of Cu3 -X for CO2 -to-C2 H4 conversion can be adjusted from 31.90 % to 55.01 % by simply replacing the counter anions (NO3- , Cl- , Br- ). The DFT calculation results verify that Cu3 -X can facilitate the C-C coupling of identical *CHO intermediates, subsequently forming molecular symmetrical C2 H4 product. This work provides an important molecular model system and a new design perspective for electroreduction of CO2 to C2 products with symmetrical molecular structure.