These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Preprints are manuscripts made publicly available before they have been submitted for formal peer review and publication. They might contain new research findings or data. Preprints can be a draft or final version of an author's research but must not have been accepted for publication at the time of submission.
Biological and heterogenous catalysts for electrochemical CO2 reduction often exhibit a high degree of electronic delocalization that serves to minimize overpotential and maximize selectivity over hydrogen evolution. Here, we report a molecular iron(II) complex that achieves a similar feat as a result of strong metal–ligand exchange coupling. This interaction promotes an open-shell singlet electronic structure that drives the electrochemical reduction of CO2 to CO with over 90% selectivity and turnover frequencies of 100,000 s−1 at low overpotentials, with no degradation over 20 hours. The decrease in the thermodynamic barrier engendered by this strong metal–ligand exchange coupling enables homogeneous CO2 reduction catalysis in water without compromising reaction selectivity.