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Reactive Ion Surface Scattering as an Eley–Rideal Process: A Molecular Dynamics Study into the Abstraction Reaction Mechanism by Low Energy Cs + From Pt(111)
Author(s) -
Lahaye Rob J. W. E.,
Kang Heon
Publication year - 2004
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.200300983
Subject(s) - ion , chemistry , molecular dynamics , atomic physics , kinetic energy , chemical physics , scattering , reaction dynamics , dipole , desorption , reaction mechanism , molecule , computational chemistry , adsorption , physics , catalysis , organic chemistry , quantum mechanics , optics
We have employed a classical molecular dynamics simulation for the direct pick‐up reaction of adsorbates by very low energy (1–60 eV) ions scattered at a surface. The system investigated is the reactive ion scattering (RIS) of Cs + with an adsorbate on a Pt(111) surface. The ion–dipole attraction between the projectile and the physisorbed adsorbate drives the abstraction reaction, in which the ion projectile at first collides with the surface to release a substantial amount of its kinetic energy, and subsequently pulls the adsorbate along in the outgoing trajectory. Desorption induced by the ion–dipole attraction is a precursor to the formation of the Cs + –adsorbate product. This Eley–Rideal‐type mechanism must accommodate the inertia of the adsorbate. Consequently, a successful abstraction works well only for low mass adsorbates and slow outgoing Cs + ions. The efficient energy transfer to the Pt(111) surface makes Cs + a better candidate for RIS than lighter projectile ions. Optimal conditions for the efficient RIS abstraction mechanism are found for physisorbed adsorbates with a mass below 32 amu, and for 10 eV Cs + ions at a 45° incidence.