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Title: Dynamics of H{sub 2} 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{sub 2} from W(110) is analyzed by means of quasi-classical 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.

Authors:
; ;  [1];  [2]; ;  [3]
  1. Université de Bordeaux, ISM, CNRS UMR 5255, 33405 Talence Cedex (France)
  2. (France)
  3. Instituto de Física Rosario (IFIR) CONICET-UNR. Ocampo y Esmeralda (2000) Rosario (Argentina)
Publication Date:
OSTI Identifier:
22308780
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CROSS SECTIONS; DEGREES OF FREEDOM; DENSITY FUNCTIONAL METHOD; ENERGY DEPENDENCE; HYDROGEN; INTERPOLATION; MOLECULES; SENSITIVITY; SIMULATION; SURFACE POTENTIAL; VIBRATIONAL STATES

Citation Formats

Pétuya, R., E-mail: r.petuya@ism.u-bordeaux1.fr, Larrégaray, P., Crespos, C., CNRS, ISM, UMR5255, F-33400 Talence, Busnengo, H. F., and Martínez, A. E. Dynamics of H{sub 2} Eley-Rideal abstraction from W(110): Sensitivity to the representation of the molecule-surface potential. United States: N. p., 2014. Web. doi:10.1063/1.4885139.
Pétuya, R., E-mail: r.petuya@ism.u-bordeaux1.fr, Larrégaray, P., Crespos, C., CNRS, ISM, UMR5255, F-33400 Talence, Busnengo, H. F., & Martínez, A. E. Dynamics of H{sub 2} Eley-Rideal abstraction from W(110): Sensitivity to the representation of the molecule-surface potential. United States. doi:10.1063/1.4885139.
Pétuya, R., E-mail: r.petuya@ism.u-bordeaux1.fr, Larrégaray, P., Crespos, C., CNRS, ISM, UMR5255, F-33400 Talence, Busnengo, H. F., and Martínez, A. E. Mon . "Dynamics of H{sub 2} Eley-Rideal abstraction from W(110): Sensitivity to the representation of the molecule-surface potential". United States. doi:10.1063/1.4885139.
@article{osti_22308780,
title = {Dynamics of H{sub 2} Eley-Rideal abstraction from W(110): Sensitivity to the representation of the molecule-surface potential},
author = {Pétuya, R., E-mail: r.petuya@ism.u-bordeaux1.fr and Larrégaray, P. and Crespos, C. and CNRS, ISM, UMR5255, F-33400 Talence and Busnengo, H. F. and Martínez, A. E.},
abstractNote = {Dynamics of the Eley-Rideal (ER) abstraction of H{sub 2} from W(110) is analyzed by means of quasi-classical 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.},
doi = {10.1063/1.4885139},
journal = {Journal of Chemical Physics},
number = 2,
volume = 141,
place = {United States},
year = {Mon Jul 14 00:00:00 EDT 2014},
month = {Mon Jul 14 00:00:00 EDT 2014}
}
  • We have performed first-principles total-energy calculations of low-dimensional sections of the electronically adiabatic potential energy surface (PES) that are relevant for the Eley{endash}Rideal (ER) reaction of H atoms on a rigid Cu(111) surface. These calculations were performed within density-functional theory using a plane-wave and pseudopotential method and the generalized gradient approximation for the exchange-correlation energy. The calculated energy points for various configurations of one and two atoms on the Cu(111) surface were used to construct a model PES that can be used in ER reaction dynamics calculations. {copyright} {ital 1999 American Institute of Physics.}
  • The abstraction kinetics for atomic hydrogen (H[sub at]) removal of chemisorbed D and atomic deuterium (D[sub at]) removal of chemisorbed H are studied on single crystal Si surfaces. The surface H and D coverages are measured in real time by mass analyzing the recoiled H[sup +] and D[sup +] ion signals. On both Si(100) and Si(111) surfaces, the abstraction reactions are efficient, and have very low activation energies [congruent]0.5--1 kcal/mol. For abstraction from surfaces containing only monohydride species, the abstraction reaction probability is [congruent]0.36 times the adsorption rate of H[sub at] or D[sub at]. For the same H[sub at] andmore » D[sub at] exposures, the reaction rates for H[sub at] removal of adsorbed D and D[sub at] removal of adsorbed H are nearly identical. All observations are consistent with a generalized Eley--Rideal abstraction mechanism, and a two-dimensional quantum-mechanical model is used to calculate reaction probabilities for these reactions. According to the model, the activation energies are due to enhanced abstraction rates from excited vibrational states of the adsorbed Si--H or Si--D bond. With SiH[sub 2] and SiH[sub 3] species present on the surface, the removal rate of H using D[sub at] is decelerated, suggesting that the higher hydrides have a lower cross section for abstraction.« less
  • CO{sub 2} is one of the most abundant components of ices in the interstellar medium; however, its formation mechanism has not been clearly identified. Here we report an experimental observation of an Eley-Rideal-type reaction on a water ice surface, where CO gas molecules react by direct collisions with surface OH radicals, made by photodissociation of H{sub 2}O molecules, to produce CO{sub 2} ice on the surface. The discovery of this source of CO{sub 2} provides a new mechanism to explain the high relative abundance of CO{sub 2} ice in space.
  • Quasiclassical trajectory studies have been performed for the reaction between an H (or D) atom incident from the gas phase and a H (or D) atom adsorbed onto a Cu(111) surface. Results from a density functional calculation of the interaction between H and a Cu(111) surface are used to construct a detailed potential energy surface which contains all six nuclear degrees of freedom. Impacts of the incident atom close to the adsorbate can lead to direct Eley{endash}Rideal reactions and the dynamics of these reactions are explored. Interaction of the incident atom with the adsorbate also results in trapping, with amore » high probability. This adsorbate-mediated trapping mechanism is important for impacts within 2 {Angstrom} of the adsorbate. At larger impact parameters scattering from the corrugation also leads to trapping. These trapped {open_quotes}hot{close_quotes} atoms can go on to react with an adsorbed species, and the dynamics of such hot-atom reactions are explored. The final-state distributions of the products are examined with regard to isotope effects for the direct and hot-atom pathways, and compared with experiment. {copyright} {ital 1997 American Institute of Physics.}« less
  • The dynamics of a direct reaction between a gas phase H atom and an adsorbed H atom, often referred to as an Eley--Rideal mechanism, is explored using a fully three-dimensional flat surface model for Cu(111). The model is based on a flat-surface approximation for a single electronically adiabatic potential energy surface (PES). This reduces the inherently six-dimensional reactive scattering problem (for a rigid surface) to a three-dimensional problem by introducing three constants of motion. The resulting scattering problem is treated quantum mechanically by solving the time-dependent Schroedinger equation, and also by quasiclassical trajectory calculations. We have considered four different modelmore » PESs which are all more or less compatible with available knowledge about the interactions between hydrogen atoms and molecules and Cu(111). We have studied the dependence of the reactive cross section and product translational energy and rovibrational state distributions on the kinetic energy and angle of the incident H atom, and the vibrational state of the adsorbed H atom.« less