Unexpected Effect of Intramolecular Phenolic Group on Electrocatalytic CO2 Reduction

摘要

Iron porphyrin 1 with appending phenolic group was synthesized and examined as electrocatalyst for the carbon dioxide reduction (CO2RR). Unexpectedly, the chloride salt 1-Cl is much less active as compared to iron porphyrin 2-Cl, the structural analogue lacking the hanging phenolic group. By using the triflate salts, 1-OTf is three times more active than 1-Cl, while 2-OTf displays the same activity as 2-Cl for CO2RR. The observed trend 1-OTf>2-OTf=2-Cl>1-Cl indicates that the phenolic group has both positive effect as local proton donating site and unexpected negative effect on electrocatalytic CO2RR.