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

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