Molecular Beam Study of CO Oxidation on a (111) Platinum Surface.
INTELCOM RAD TECH SAN DIEGO CALIF
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The heterogeneous oxidation of CO on epitaxially grown Pt111 surfaces has been investigated using modulated molecular beam techniques. The overall reaction is apparently first order. The observance of higher order kinetics in these experiments is argued to be an artiface of the beam technique used here and suggests a high surface diffusion rate for adsorbed CO. The measured angular dependence of the CO2 desorption rate from the Pt111 surfaces does not follow the Knudsen law of random cosine desorption, but is much more sharply peaked about the surface normal. The adsorption of CO is also shown to have an angular dependence and is not activated on Pt111. The results of this study strongly suggest that a Langmuir-Hinshelwood mechanism dominates the reaction, with CO being the principal diffusing species. Modified author abstract
- Physical Chemistry