Unexpected Solvent Effect in Electrocatalytic CO2 to CO Conversion Revealed Using Asymmetric Metalloporphyrins
By Sinha, Soumalya; Warren, Jeffrey J.
Published in Inorganic Chemistry
2018
Abstract
Rapid and efficient electrochemical CO2 reduction is an ongoing challenge for the production of sustainable fuels and chemicals. In this work, electrochemical CO2 reduction is investigated using metalloporphyrin catalysts (metal = Mn, Fe, Co, Ni, Cu) that feature one hydroxyphenyl group, and three other phenyl groups, in the porphyrin heterocycle (5-(2-hydroxyphenyl)-10,15,20-triphenylporphyrin, TPOH). These complexes, which are minimal versions of related complexes bearing up to eight proton relays, were designed to allow more straightforward determination of the role of the 2-hydroxylphenyl functional group. The iron-substituted version of TPOH supports robust reduction of CO2 in acetonitrile solvent, where carbon monoxide is the only detected product. Addition of weak Br