Mechanistic insights into the CO2 reduction to ethylene catalyzed by F-modified Cu/graphene composites

Fluorine-modified copper catalysts are expected to improve electrocatalytic CO2 reduction performance. In addition to active species, the cluster/support interaction in cluster-loaded catalysts has been shown to vary according to both the inherent reactivity of the metal cluster and the properties of the support. Herein, Cu loaded fluorine-doped graphene catalyst (Cu/FDG) was designed and the mechanism of Cu/FDG-catalytic reduction of CO2 into ethylene were explored. F strengthens the interaction between Cu4 and graphene surface, promoting the electron transfer of Cu clusters to the fluorine-modified graphene due to the inductive effect, which results in the formation of both Cu0 and oxidized Cuδ+ species. These species hence accelerate the adsorption of *CO, while the *CO coupling favors the generation of ethylene on the top site of Cu4 cluster due to the undercoordinated environment. The electrophilic effect guiding interface charge population can be applied to tune the reaction selectivity of Cu-catalytic reduction of CO2.