(471c) Mechanical Strain Tuning of the Hydrogen Evolution Reaction

We show how the direct application of mechanical strain changes the activity of electrocatalysts in the hydrogen evolution reaction, and we compare the direction of response of Cu, Ni, and Pt catalysts with predictions from the well-known hydrogen evolution “volcano plot”. An understanding of the interaction between chemical reactants and catalyst surfaces is critical for the  efficient control of electrocatalytic activity and thus for the design of novel functional materials. Lattice strain has been implicated in enhanced or suppressed activity of many synthesized catalysts, but in most cases the effect of strain is not cleanly separated from the ligand effect. Here we show new experimental results of a “pure” strain effect by the continuous application of mechanical strain on metal thin-film catalysts, which we show directly tunes the catalytic activity for the hydrogen evolution reaction. We compare the results to density functional theory calculations of uniaxial loading, as well as the qualitative predictions from the well-known volcano plot. Specifically, we observe that Pt and Ni catalysts display enhanced activity upon compressive loading and suppressed activity upon tension, while Cu catalysts display the opposite qualitative response.