Synergistic Effects of Imidazolium-Functionalization on fac-Mn(CO)₃ Bipyridine Catalyst Platforms for...

The electrocatalytic reduction of carbon dioxide (CO₂) could be a powerful tool for generating chemical fuels and feedstock molecules relevant to the chemical industry. One of the major challenges for molecular catalysts remains the necessity of high overpotentials, which can be overcome by identifying novel routes that improve the energetic reaction trajectory of critical intermediates during catalysis. In this combined experimental and computational study, we show that imidazolium functionalization of molecular fac-Mn(CO)₃ bipyridine complexes results in CO₂ reduction at mild electrochemical potentials in the presence of H₂O. Importantly, our studies suggest that imidazolium groups in the secondary coordination sphere promote the formation of a local hydration shell that facilitates the protonation of CO₂ reduction intermediates. As such, we propose a synergistic relationship between the functionalized catalyst and H₂O, which stands in contrast to other systems in which the presence of H₂O frequently has detrimental effects on catalysis.