We investigated the correlation between the 2-position substituent lengths of benzimidazole-based Cu coordination polymers and their acidic CO2 electroreduction performance. We presented that lengthening the substituent reduces local proton concentrations and Cu-Cu coordination numbers of the exsolved metallic Cu. This promotes the conversion of CO2-derived CO into multi-carbon products and CH4. Details can be found in Nat. Commun.
