Molecular Electrocatalyst Enables Direct Electrochemical Capture and Conversion of CO ₂ up to Atmospheric Concentration

The conversion of low-concentration CO₂ streams into fuel is highly desirable for industrial applications, avoiding energy-intensive CO₂ capture and concentration. Here, we report a highly active molecular electrocatalyst, fac-[Mn(CO)₃(bis-MeNHC)(MeCN)]⁺ (1-MeCN⁺), which enables the direct electrochemical reduction of near-atmospheric CO₂ concentrations to CO with up to 100% Faradaic efficiency. Voltammetric analysis at varying CO₂ concentrations reveals a clear transition between distinct kinetic regimes, shifting from pure kinetic control to a regime dominated by CO₂ depletion. Kinetic analysis in the 5%-100% CO₂ range reveals a first-order dependence on substrate concentration. Infrared spectroelectrochemistry confirms that the electrogenerated anionic catalyst remains active under extremely diluted CO₂ conditions. Computational modeling further supports that the CO₂-to-CO conversion mediated by the doubly reduced species is kinetically accessible at atmospheric CO₂ levels. This work demonstrates molecular electrocatalysis even at CO₂ concentrations as low as 420 ppm (i.e. atmospheric CO₂ partial pressure).