Ambient conversion of CO2 to hydrocarbons by biogenic and synthetic [Fe4S4] clusters

The Fe protein of nitrogenase contains a redox active [Fe4S4] cluster that plays a key role in electron transfer and substrate reduction. Here we show that the Fe protein of Methanosarcina acetivorans can reduce CO2 and CO to hydrocarbons under ambient conditions. Further, we demonstrate that this reactivity is inherent to [Fe4S4] clusters, showing the ability of a synthetic [Fe4S4] compound to catalyse the same ambient reaction in solutions. Theoretical calculations suggest a reaction mechanism involving an aldehyde-like intermediate that gives rise to hydrocarbon products upon proton-coupled electron transfer and concomitant removal of water molecules. These results provide a framework for mechanistic investigations of FeS-based activation and reduction of CO2 and CO while facilitating potential development of FeS catalysts capable of ambient conversion of CO2 and CO into fuel products.