Coverage dependence of molecular adsorption dynamics: ethane on platinum (111). Arumainayagam, Christopher R.; McMaster, Mark C.; Madix, Robert J. Dep. Chem., Stanford Univ., Stanford, CA, USA. J. Phys. Chem. (1991), 95(6), 2461-5. CODEN: JPCHAX ISSN: 0022-3654. Journal written in English. CAN 114:129855 AN 1991:129855 CAPLUS (Copyright 2001 ACS)

The dynamics of associative adsorption of ethane on Pt(111) as a function of ethane coverage was probed with supersonic mol. beam techniques. Adsorption probabilities were measured directly at coverages ranging from 0 to monolayer satn. at incident translational energies between 10 and 40 kJ/mol and incident angles between 0 and 60° at a surface temp. of 95 K. In contrast to the predictions of the original P. Kisliuk (1957) model, at all incident translational energies and incident angles the adsorption probability increases with ethane coverage up to near monolayer coverage. This behavior can be fitted quite adequately by a model that incorporates enhanced adsorption onto the covered surface compared to the clean surface, utilizing the exptl. value of the adsorption probability onto the satd. monolayer. The angular dependence of the adsorption probability shows progressive deviation from normal energy scaling with increasing surface coverage, suggesting that the effective corrugation of the gas surface interaction potential increases with adsorbate coverage.