Electrocatalytic Hydrogen Evolution of Cobalt Triaryl Corrole Bearing Methylsulphonyl Group

Abstract Environmentally sustainable hydrogen energy electrocatalysts play a pivotal role in advancing renewable energy systems. In this study, we present the synthesis of three new cobalt tri‐ aryl corrole complexes (1, 2, 3) with varying methylsulphonyl substitutions and their electrocatalytic hydrogen evolution reaction (HER) activity. The number of peripheral methylsulphonyl groups has significant effect on their HER performance, and the tri‐methylsulphonyl substituted cobalt corrole exhibits the best activity. The HER activity increases with the increase of the number of methylsulphonyl. When using TsOH as the proton source, complexes 2 and 3 demonstrated high turnover frequencies (TOF) of 96.47 and 108.97 s ⁻¹ , respectively. The electrocatalytic HER goes via EECC or EECEC (E: electron transfer step, C: chemical step) pathways. Notably, complexes 2 and 3 achieved faradaic efficiencies (FE) of 81.3% and 85.7% in aqueous media.