Dynamics of H2 Eley-Rideal abstraction from W(110): Sensitivity to the representation of the molecule-surface potential

Abstract

Dynamics of the Eley-Rideal (ER) abstraction of H 2 from W(110) is analyzed by means of quasiclassical trajectory calculations. Simulations are based on two different molecule-surface potential energy surfaces (PES) constructed from Density Functional Theory results. One PES is obtained by fitting, using a Flexible Periodic London-Eyring-Polanyi-Sato (FPLEPS) functional form, and the other by interpolation through the corrugation reducing procedure (CRP). Then, the present study allows us to elucidate the ER dynamics sensitivity on the PES representation. Despite some sizable discrepancies between both H+H/W(110) PESs, the obtained projectile-energy dependence of the total ER cross sections are qualitatively very similar ensuring that the main physical ingredients are captured in both PES models. The obtained distributions of the final energy among the different molecular degrees of freedom barely depend on the PES model, being most likely determined by the reaction exothermicity. Therefore, a reasonably good agreement with the measured final vibrational state distribution is observed in spite of the pressure and material gaps between theoretical and experimental conditions.

Energy Dissipation to Tungsten Surfaces upon Eley–Rideal Recombination of N2 and H2

“…These areas differ from the ones from previous works 45,46,49 because it was found that few ER recombination events occur for trajectories starting outside of the smaller sampling area previously used. Nevertheless, despite some quantitative differences between the present and the previous results, all the conclusions remain.…”

Communication: Hot-atom abstraction dynamics of hydrogen from tungsten surfaces: The role of surface structure

“…The former mechanism involves direct collision between a scattering atom (projectile) and an adsorbed species (target), 30 while the latter is governed by hyperthermal diffusion of the projectile onto the surface prior to abstraction. 31 The influence of the crystal face has been recently scrutinized theoretically for the Eley-Rideal (ER) recombination a) pascal.larregaray@u-bordeaux.fr of hydrogen and nitrogen on the W(100) and W(110) surfaces, [32][33][34][35][36] accounting for dissipation to surface phonons and electrons. 37 In these direct ultrafast processes, the surface is thought to mostly behave as a spectator.…”

“…Since the actual fate of such trajectories is unknown, the corresponding contribution is taken as an uncertainty to any possible outcome of scattering. 35,36,43 The vibration of the formed H 2 molecules has been semiclassically quantized via the Gaussian weighting procedure. [57][58][59] In order to rationalize nonadiabatic effects upon scattering, molecular dynamics simulations are performed within the Born-Oppenheimer static surface (BOSS) approximation and within the local density friction approximation (LDFA).…”

“…For both surfaces, the classical equations of motion are integrated for one projectile atom and 18 adsorbed targets with initial positions and velocities given by the ZPE as detailed in previous studies. 35,36 The initial altitude of the projectile is taken in the asymptotic region of the potential, at Z p = 7.0 Å from the surface. The (X p , Y p ) initial position of the projectile is randomly sampled in the covered surface irreducible cell (yellow areas of Fig.…”

Isotope Effects in Eley–Rideal and Hot-Atom Abstraction Dynamics of Hydrogen from Tungsten (100) and (110) Surfaces

“…31 In addition, the single adsorbate study has been here performed with FPLEPS PES, whereas the multiadsorbate potential was developed from a CRP PES, which leads to higher ER reactivity as previously investigated. 29 The influence of isotope effects observed in single adsorbate studies is also present here. Homonuclear combinations of isotopes lead to similar cross sections, whereas the reactivity for heteronuclear combinations is ordered by the (m p /m t ) ratio.…”