Charge transfer complex mediated conversion of CO2 to CO fuel

Abstract Carbon monoxide (CO) is a versatile feedstock for the production of synthetic fuels using Fischer-Tropsch (FT) chemistry and a broader range of compounds using acylation chemistry. Commercial CO derives from natural gas, petroleum, and coal. In order to mitigate the dependence on fossil resources and assure a sustainable future, scientific communities are indefatigably pursuing electrochemical/photochemical conversion of ubiquitous carbon dioxide (CO2) back to useful chemicals like CO. But large-scale deployment of the technologies is hindered by low production rate, low conversion efficiency, and rigorous demands on the catalysts/devices. Here we show a chemical reduction strategy capable of rapid and large-scale conversion of CO2 into combustible CO (chromatographic purity > 99%) at ambient temperature. The process only involves three industrial materials including copper (Cu), zinc (Zn), and N-methylimidazole (NMI) and exempts special installation, thus favoring practical implementation. The unprecedented efficiency is attributed to the mediation of the charge transfer complex [CuI∙∙∙NMI•‒] formed through spontaneous charge transfer interaction between NMI and Cu. [CuI∙∙∙NMI•‒] is an efficient mediator that can transform inert CO2 to CO2−CO2•‒ and stabilize this key intermediate. Zn then induces the reductive disproportionation of CO2−CO2•‒ into CO.