Metalloporphyrin-Based Catalysts for CO2 Reduction: Effects of Metal Ions and Acidic Sites

Abstract

Low product selectivity and poor long-term stability impede the use of metalloporphyrins as practical catalysts in large-scale CO2 reduction reactions. Metalloporphyrin has been a bench mark catalyst to be used in the CO2 reductions. A variety of reaction conditions and a broad range of porphyrinic molecules have been examined with moderate to good efficiencies in comparison with other homogeneous catalysts. Additionally, due to the presence of a large π conjugation system presence in the macrocycle, porphyrins can readily interact with 2D materials through π-π interactions. Therefore, it is also a molecule commonly used to fabricate into hybrid materials. One of long-term goals in our lab is to examine the potential applications of porphyrin isomers or porphyrin analogues. In this report, we will focus on the effects of central metal ions and the presence of acidic protonation/deprotonation sites on the porphyrinic molecules to the product selectivity and the catalytic efficiency upon the CO2 reduction reactions. Both photocatalytic and electrochemical catalytic systems will be compared and contrasted in the presentation.