Sulfur poisoning of emergent and current electrocatalysts: vulnerability of MoS2, and direct correlation to Pt hydrogen evolution reaction kinetics

Abstract

The recent surge in interest in the utilisation of transition metal dichalcogenides for the hydrogen evolution reaction (HER), as well as the long-standing problem of sulfur poisoning suffered by the established Pt HER electrocatalyst, motivated us to examine the impacts of sulfur poisoning on both emergent and current electrocatalysts. Through a comparative study between MoS₂ and Pt/C on the effects of sulfur poisoning, we demonstrate that MoS₂ is not invulnerable to poisoning. Additionally, using X-ray photoelectron spectroscopy, correlations have also been established between the atomic percentages of Pt–S bonds and normalised HER parameters e.g. Tafel slope and potential at −10 mA cm⁻². These findings are of high importance for potential hydrogen evolution catalysis.