Tensile Strain on Pt(111) Boosts Hydrogen Evolution Reaction Kinetics in Acids

The free energy of hydrogen adsorption (Δ G H ) is a key descriptor for hydrogen evolution reaction (HER) kinetics in acids, although it is often limited in explaining facet- and strain-dependent catalytic activity. Here, we investigate the role of tensile strain on Pt(111) surfaces, focusing on the competitive adsorption between hydrogen and water. Combining computational and experimental studies, we demonstrate that tensile strain enhances hydrogen and water adsorption, resulting in the 1.3-fold enhancement in exchange current density compared to unstrained Pt(111). Our findings suggest that the Δ G H -based HER trends may not fully capture the influence of interfacial factors under structural deformation.