Title

Substrate-mediated Dispersion Interaction Effects In The Properties Of A Physisorbed Gas

Document Type

Article

Publication Date

9-1-1993

Publication Title

Journal Of Chemical Physics

Department

Physics

Abstract

The theory of substrate-mediated dispersion interactions is applied to analyze a set of quasiequilibrium measurements of adsorption isobars and desorption isotherms of the CH4/Ag(011) physisorption system. The theory provides for the construction of an adsorbate intermolecular potential from the gas phase potential, with the spacing between the metal surface and the adsorbed layer as the sole adjustable parameter. The best fits to the kinetic and thermodynamic data yield a consistent intermolecular potential, with a well depth of approximately two-thirds of the free space value. The limited dynamic range of the measurements does not permit a determination of the form of the intermolecular potential. However, the good agreement of the theory with both data sets lends strong support for the quasiequilibrium model, and supports the proposition that the properties of physisorbed layers can be predicted using gas phase potentials while accounting for substrate-mediated dispersion interaction effects.

Volume

99

Issue

5

pp.

4152-4159

ISSN

0021-9606