Electrocatalysis of hydrogen evolution reaction on Pt electrode surface-modified by chemisorption

Kinetic studies of hydrogen evolution reaction (HER) at the surface of Pt in alkaline conditions, reported in this paper, show that electrocatalytic activity is enhanced after adsorption of S - 2 ions. EIS and steady-state polarization curve data pointed to an undoubted improvement in performance with the Pt–S cathode that was attributed to higher adsorbed hydrogen coverage. Experimental findings suggested an increase in the electronic density of the modified surface sites that may strengthen the interaction between H2O and the adsorption site and, consequently, accelerates the Volmer step.