Accession Number : AD0770032

Title :   Molecular Beam Study of CO Oxidation on a (111) Platinum Surface.

Descriptive Note : Technical rept.,


Personal Author(s) : Palmer,Robert L. ; Smith,Joe N. , Jr

Report Date : 10 SEP 1973

Pagination or Media Count : 42

Abstract : The heterogeneous oxidation of CO on epitaxially grown Pt(111) 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 Pt(111) 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 Pt(111). 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)

Descriptors :   (*Carbon monoxide, *Oxidation), (*Platinum, Surface chemistry), Catalysts, Molecular beams, Adsorption, Carbon dioxide, Epitaxial growth, Reaction kinetics, Angles, Distribution, Desorption

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE