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.

Post-dissociation Dynamics of N2 on Ru(0001): How Far Can the “Hot” N Atoms Travel?

“…On the other hand, the one at the fcc site at the transition state is more likely to travel, across one or two Ru surface lattice units (2.7 Å). This behavior, namely, only one of the two atomic adsorbates is involved in diffusion, is quite similar to the hot H dynamics after the dissociation of H 2 . ,, In Figure , the N–N separation averaged over all of the dissociated trajectories is shown as a function of time. Here, the N–N distance is computed directly from their Cartesian coordinates.…”

“…Indeed, our recent work on H spillover had shown that interactions with substrate EHPs significantly slow down the diffusion of adsorbed H atoms, leading to smaller diffusion coefficients than those obtained via adiabatic simulations. 39,40 In addition, previous studies on N diffusion on metal surfaces have demonstrated that the nonadiabatic friction is typically minor. 27 If the electronic friction were to be included in our simulation, it can be expected that the final N−N separation would be even smaller.…”

“…This behavior, namely, only one of the two atomic adsorbates is involved in diffusion, is quite similar to the hot H dynamics after the dissociation of H 2 . 39,40,54 In Figure 3, the N−N separation averaged over all of the dissociated trajectories is shown as a function of time.…”

“…They often have very different behaviors, and the understanding of their roles in surface processes is a hot topic in surface dynamics. − For our system here, an accurate characterization of the energy dissipation is the key to understanding the experimental observations. Here, we report an extensive theoretical investigation of the N 2 dissociative chemisorption on Ru(0001) and the subsequent hot N atom dynamics, using an approach adapted in our recent work on hydrogen spillover. , …”

First-principles surface reaction rates by ring polymer molecular dynamics and neural network potential: role of anharmonicity and lattice motion

“…In an early work, Suleimanov applied the RPMD rate theory to calculate diffusion constants of hydrogen on Ni(100) with an embedded atom method interatomic potential. 51 More recently, non-equilibrium RPMD simulations for gas-surface scattering have been carried out to calculate dissociative sticking probabilities [52][53][54][55] and diffusion constants of hydrogen on a single-atom catalytic surface 56 .…”