Non‐noble metal molecular catalysts mediating the electrocatalytic reduction of carbon dioxide are still scarce. This work reports the electrochemical reduction of CO2 to formate catalyzed by the bimetallic complex [(bdt)MoVI(O)S2CuICN]2‐ (bdt = benzenedithiolate), a mimic of the active site of the Mo‐Cu carbon monoxide dehydrogenase enzyme (CODH2). Infrared spectroelectrochemical (IR‐SEC) studies coupled with density functional theory (DFT) computations revealed that the complex is only a pre‐catalyst, the active catalyst being generated upon reduction in the presence of CO2. We found that the two‐electron reduction of [(bdt)MoVI(O)S2CuICN]2‐ triggers the transfer of the oxo moiety to CO2 forming CO3 2‐and the complex [(bdt)MoIVS2CuICN]2– and that a further oneelectron reduction is needed to generate the active catalyst. Its protonation yields a reactive MoVH hydride intermediate which reacts with CO2 to produce formate. These findings are particularly relevant to the design of catalysts from metal oxo precursors.
A Bioinspired Molybdenum-Copper Molecular Catalyst for CO2 Electroreduction
24 February 2020, Version 1
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