Accession Number : AD0690818

Title :   THERMODYNAMICS AND KINETICS OF HETEROGENEOUS REACTIONS.

Descriptive Note : Technical rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS

Personal Author(s) : Batty,J. Clair ; Stickney,Robert E.

Report Date : 02 JUN 1969

Pagination or Media Count : 72

Abstract : A generalized treatment of heterogeneous chemical reactions is developed and applied to several sublimation, catalytic, and oxidation processes. The approach is essentially a systematic reformulation of the quasi-equilibrium analyses of Langmuir, Richardson, and others, and it is generalized to apply also to conditions encountered in molecular-beam studies of gas-solid interactions. An advantage of the quasi-equilibrium approach is that it minimizes the use of kinetics to the degree that rate expressions are obtained without assuming detailed kinetic models of the processes. In Part I, the simple sublimation processes (vaporization, thermionic emission, and self-surface ionization) and catalytic reactions (surface ionization and molecular dissociation) are considered. The reaction of gaseous oxygen with solid tungsten, molybdenum, and graphite is treated in Part II for steady-state conditions, and this treatment is extended in Part III to the transient case of flash desorption of oxides from a tungsten surface. The theoretical results are compared with existing experimental data, and the agreement is surprisingly good in view of the simplicity of the approach. (Author)

Descriptors :   (*SURFACE PROPERTIES, *CHEMICAL REACTIONS), (*SUBLIMATION, SURFACE PROPERTIES), (*CATALYSIS, SURFACE PROPERTIES), (*OXIDATION, SURFACE PROPERTIES), REACTION KINETICS, GASES, IONIZATION, OXYGEN, TUNGSTEN COMPOUNDS, MOLYBDENUM COMPOUNDS, GRAPHITE, ABLATION, MASS SPECTROSCOPY, THERMIONIC EMISSION, OXIDES, TUNGSTEN

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE