Dynamics of Dissociative Chemisorption Methane on Rhodium.
ILLINOIS UNIV URBANA COORDINATED SCIENCE LAB
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The authors have studied the dissociation of methane and some of its isotopes on a clean rhodium crystal. The aim of the work has been to probe the nature of the elementary excitations which are important in bringing about dissociation and subsequent adsorption. In this study molecular beam techniques and field emission microscopy were combined. Excitation of the gas alone is sufficient to bring about reaction with a clean rhodium surface. The barrier to dissociation of CH4 is determined from the dependence of reaction rate upon gas temperature. The results are well described by a model invoking molecular adsorption of the methane molecule, with concomitant equilibration of its translational energy, followed by dissociation of those molecules which have sufficient vibrational energy to extend the H-H distance beyond its normal value of 1.78A. Modified author abstract
- Atomic and Molecular Physics and Spectroscopy