Short- and Long-Time Dynamics of Hydrogen Spillover from a Single Atom Platinum Active Site to the Cu(111) Host Surface

Abstract

Dynamics of the dissociative chemisorption of H2 (D2) and the subsequent H* (D*) diffusion on the Pt doped Cu(111) surface are investigated using both quasi-classical trajectory (QCT) and ring polymer molecular dynamics (RPMD) approaches. The classical dynamics is also studied with electronic friction to simulate the nonadiabatic interaction with surface electron–hole pairs. These dynamics calculations were made possible by a high-dimensional potential energy surface, machine learned from density functional theory data. It is shown that the diffusion of adsorbed H* at moderate temperatures can be largely characterized by classical mechanics, as evidenced by roughly the same diffusion coefficients obtained from QCT and RPMD calculations. In the long-time limit, the diffusion coefficient computed by averaging classical trajectories with electronic friction is in reasonably good agreement with the latest experimental data, underscoring the importance of the nonadiabatic interaction for H* diffusion on metal surfaces.