Electrochemical CO₂ Reduction by Urea Hangman Mn Terpyridine species

Abstract

Based on our previous study in chemical subtleties of the proton tunneling distance for metal hydride formation (PTD‐MH) to regulate the selectivity of CO2 reduction reaction (CO2RR), we have developed a family of Mn terpyridine derivatives, in which urea groups functioning as multipoint hydrogen‐bonding hangman to accelerate the reaction rate. We found that such changes to the second coordination sphere significantly increased the turnover frequency (TOF) for CO2 reduction to ca. 360 s‐1 with this family of molecular catalysts while maintaining high selectivity (ca. 100% ± 3) for CO even in the presence of a large amount of phenol as proton source. Notably, the compounds studied in this manuscript all exhibit large value for CO as that achieved by Fe porphyrins derivates, while saving up to 0.55 V in overpotential with respect to the latter.