Electrocatalytic CO2 reduction at low overpotentials using iron(III) tetra(meso-thienyl)porphyrins

The optical and electrochemical properties, as well as the CO₂ reduction capability of two different iron(III) thienyl-porphyrins, iron(III) tetra(meso-thien-2-yl)porphyrin (FeTThP) and iron(III) tetra(meso-5-methylthien-2-yl)porphyrin (FeTThMeP), are directly compared to those of iron(III) tetra(meso-phenyl)porphyrin (FeTPP). Through exploitation of mesomeric stabilization effects, FeTThP and FeTThMeP both reduced CO₂ to CO with comparable faradaic efficiencies and TON_CO relative to FeTPP, with an overpotential 150 mV lower than the benchmark catalyst.