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 TONCO relative to FeTPP, with an overpotential 150 mV lower than the benchmark catalyst.