A PEGylated Tin Porphyrin Complex for Electrocatalytic Proton Reduction: Mechanistic Insights into Main‐Group‐Element Catalysis
Ashwin Chaturvedi, Gavin A. McCarver, Soumalya Sinha, Elijah G. Hix, Konstantinos D. Vogiatzis, Jianbing Jiang
Abstract
Abstract Electrocatalytic proton reduction to form dihydrogen (H 2 ) is an effective way to store energy in the form of chemical bonds. In this study, we validate the applicability of a main‐group‐element‐based tin porphyrin complex as an effective molecular electrocatalyst for proton reduction. A PEGylated Sn porphyrin complex ( SnPEGP ) displayed high activity (−4.6 mA cm −2 at −1.7 V vs. Fc/Fc + ) and high selectivity (H 2 Faradaic efficiency of 94 % at −1.7 V vs. Fc/Fc + ) in acetonitrile (MeCN) with trifluoroacetic acid (TFA) as the proton source. The maximum turnover frequency (TOF max ) for H 2 production was obtained as 1099 s −1 . Spectroelectrochemical analysis, in conjunction with quantum chemical calculations, suggest that proton reduction occurs via an electron‐chemical‐electron‐chemical (ECEC) pathway. This study reveals that the tin porphyrin catalyst serves as a novel platform for investigating molecular electrocatalytic reactions and provides new mechanistic insights into proton reduction.