Controlling the Polarity of Metal–Organic Frameworks to Promote Electrochemical CO ₂ Reduction

Abstract The addition of polar functional groups to porous structures is an effective strategy for increasing the ability of metal–organic frameworks (MOFs) to capture CO 2 by enhancing interactions between the dipoles of the polar functional groups and the quadrupoles of CO 2 . However, the potential of MOFs with polar functional groups to activate CO 2 has not been investigated in the context of CO 2 electrolysis. In this study, we report a mixed‐ligand strategy to incorporate various functional groups in the MOFs. We found that substituents with strong polarity led to increased catalytic performance of electrochemical CO 2 reduction for these polarized MOFs. Both experimental and theoretical evidence indicates that the presence of polar functional groups induces a charge redistribution in the micropores of MOFs. We have shown that higher electron densities of sp 2 ‐carbon atoms in benzimidazolate ligands reduces the energy barrier to generate *COOH, which is simultaneously controlled by the mass transfer of CO 2 . Our research offers an effective method of disrupting local electron neutrality in the pores of electrocatalysts/supports to activate CO 2 under electrochemical conditions.