Heterogeneous Electrochemical Carbon Dioxide Reduction in Aqueous Medium Using a Novel N4-Macrocyclic Cobalt Complex.

Molecular catalysts represent an exceptional class of materials in the realm of electrochemical carbon dioxide reduction (CO 2 RR), offering distinct advantages owing to their adaptable structure, which enables precise control of electronic configurations and outstanding performance in CO 2 RR. This study introduces an innovative approach to heterogeneous electrochemical CO 2 RR in an aqueous environment, utilizing a newly synthesized N4-macrocyclic cobalt complex generated through a dimerization coupling reaction. By incorporating the quaterpyridine moiety, this cobalt complex exhibits the capability to catalyze CO 2 RR at low overpotentials and reaches near-unity CO production across a wide potential range, as verified by the online mass spectrometry and in situ attenuated total reflectance-Fourier transform infrared spectroscopy. Comprehensive computational models demonstrate the superiority of utilizing quarterpyridine moiety in mediating CO 2 conversion compared to the counterpart. This work not only propels the field of electrochemical CO 2 RR but also underscores the promising potential of cobalt complexes featuring quaterpyridine moieties in advancing sustainable CO 2 conversion technologies within aqueous environments.