Polyquinone Modification Promotes CO2 Activation and Conversion to C2+ Products over Copper Electrode

Electrocatalytic CO 2 reduction to value-added chemicals is a promising route to address the global warming problem. However, it still confronts low conversion efficiency and poor selectivity, due to difficulties in activating the inert CO 2 molecule and controlling the complex reaction pathways. Here, we put forward an unconventional approach to activating CO 2 by utilizing the quasi-reversible bonding between electrochemically reduced quinone groups and CO 2 . Through surface modification with polyquinone, the C 2+ production is effectively enhanced on a polycrystalline Cu foil model electrode. By further incorporating the polyquinone into a Cu gas diffusion electrode (GDE), a high C 2 H 4 partial current density of 325 mA/cm 2 is achieved at a low cell voltage of 3.5 V for CO 2 /pure water coelectrolysis. Combined with in situ ATR-SEIRAS study, the increased C 2+ product selectivity is attributed to the quinone-accelerated CO 2 -to-*CO conversion, which creates a high *CO coverage on Cu surface and thus facilitates C–C coupling for C 2+ production.