Renewable Formate from C–H Bond Formation with CO2: Using Iron Carbonyl Clusters as Electrocatalysts

ConspectusAs a society, we are heavily dependent on nonrenewable petroleum-derived fuels and chemical feedstocks. Rapid depletion of these resources and the increasingly evident negative effects of excess atmospheric CO2 drive our efforts to discover ways of converting excess CO2 into energy dense chemical fuels through selective C–H bond formation and using renewable energy sources to supply electrons. In this way, a carbon-neutral fuel economy might be realized.To develop a molecular or heterogeneous catalyst for C–H bond formation with CO2 requires a fundamental understanding of how to generate metal hydrides that selectively donate H– to CO2, rather than recombining with H+ to liberate H2. Our work with a unique series of water-soluble and -stable, low-valent iron electrocatalysts offers mechanistic and thermochemical insights into formate production from CO2. Of particular interest are the nitride- and carbide-containing clusters: [Fe4N(CO)12]− and its derivatives and [Fe4C(CO)12]2–. In both aqueous ...