Abstract
We have used transition-state theory to study the diffusion of short n-alkanes (n-butane-n-decane) on a model Pt(111) surface. We have determined diffusion energy barriers, preexponential factors, and characteristic mechanisms by which these molecules diffuse. Our studies reveal novel features associated with molecular mobility, including: Non-nearest-neighbor hops, local minima, conformational correlations, and directional anisotropy induced by molecular orientation. We examine factors that contribute to the relationship between molecular size and mobility. Tracer-diffusion coefficients for these molecules are best described by a heterogeneous lattice model. Diffusion coefficients calculated using this model agree well with those from experimental studies.
Original language | English (US) |
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Pages (from-to) | 1626-1635 |
Number of pages | 10 |
Journal | Journal of Chemical Physics |
Volume | 108 |
Issue number | 4 |
DOIs | |
State | Published - Jan 22 1998 |
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy
- Physical and Theoretical Chemistry