Coordination Environment Engineering of Metal Centers in Coordination Polymers for Selective Carbon Dioxide Electroreduction toward Multicarbon Products

Electrocatalytic carbon dioxide reduction reaction (CO2RR) toward value-added chemicals/fuels has offered a sustainable strategy to achieve a carbon-neutral energy cycle. However, it remains a great challenge to controllably and precisely regulate the coordination environment of active sites in catalysts for efficient generation of targeted products, especially the multicarbon (C2+) products. Herein we report the coordination environment engineering of metal centers in coordination polymers for efficient electroreduction of CO2 to C2+ products under neutral conditions. Significantly, the Cu coordination polymer with Cu–N2S2 coordination configuration (Cu–N–S) demonstrates superior Faradaic efficiencies of 61.2% and 82.2% for ethylene and C2+ products, respectively, compared to the selective formic acid generation on an analogous polymer with the Cu–I2S2 coordination mode (Cu–I–S). In situ studies reveal the balanced formation of atop and bridge *CO intermediates on Cu–N–S, promoting C–C coupling for C2+ production. Theoretical calculations suggest that coordination environment engineering can induce electronic modulations in Cu active sites, where the d-band center of Cu is upshifted in Cu–N–S with stronger selectivity to the C2+ products. Consequently, Cu–N–S displays a stronger reaction trend toward the generation of C2+ products, while Cu–I–S favors the formation of formic acid due to the suppression of C–C couplings for C2+ pathways with large energy barriers.