Studies on Activated Chemisorption.
Abstract
Chemisorption of methane has been examined on highly perfect rhodium surfaces by a combination of field emission and molecular beam techniques in order to explore the mechanism of activation. It has been found that dissociative adsorption can be initiated on rhodium at 245 K just by excitation of the gas. Quantitative rate studies as a function of gas temperature have established that the CH4 molecule must overcome an activation barrier of 7 kcal/mole for reaction to occur. Evidence suggests that translational and rotational motion are not directly involved in passing over the barrier. Vibrational excitation of methane molecules appears to be the significant step in the reaction at the surface. Slater's dynamical model of unimolecular reactions leads to a sizable isotope effect for the rate of dissociation, and the semi-quantitative data presently available are best explained by his model.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1974
- Accession Number
- ADA006785
Entities
People
- Charles N. Stewart
- Gert Ehrlich
Organizations
- University of Illinois Urbana–Champaign