Partial Coordination-Perturbed Bi-Copper Sites for Selective Electroreduction of CO2 to Hydrocarbons.

In the electrochemical CO2 reduction reaction (CO2 RR), it is challenging to develop a stable, well-defined catalyst model system that is able to examine the influence of the synergistic effect between adjacent catalytic active sites on the selective generation of C1 or C2 products. We have designed and synthesized a stable crystalline single-chain catalyst model system for electrochemical CO2 RR, which involves four homomorphic one-dimensional chain-like compounds (Cu-PzH, Cu-PzCl, Cu-PzBr, and Cu-PzI). The main structural difference of these four chains is the substituents of halogen atoms with different electronegativity on the Pz ligands. Consequently, different synergistic effects between bi-copper centers lead to changes in the faradic efficiency (FE CH 4 :FE C 2 H 4 ). This work provides a simple and stable crystalline single-chain model system for systematically studying the influence of coordination microenvironment on catalytically active centers in the CO2 RR.