Highly Efficient and Selective Electrocatalytic CO2-to-CO Conversion by a Non-heme Iron Complex with an In-Plane N4 Ligand in Heterogeneous Aqueous Media

A non-heme Fe complex with a tetradentate dicarboxamide N-4 in-plane ligand works efficiently and selectively for the electrocatalytic CO2-to-CO conversion in a homogeneous DMF solution. The complex was immobilized on a nitrogen-doped graphene (N-G) to achieve a CO2-to-CO conversion in neutral aqueous NaHCO3 solutions, affording CO with Faradaic efficiency of 90%, a current density of 6 mA cm(-2), and a turnover frequency of 2.1 s(-1), at an overpotential of 0.47 V, which is among those of the hitherto-reported efficient and selective Fe complexes electrocatalysts.