Diffusion Theory for Adsorption and Desorption of Gas Atoms at Surfaces

Abstract

The time evolution of a nonequilibrium ensemble of gas atoms adsorbed on a solid surface is described. Adsorption and desorption rate constants and adatom (adsorbed atom) energy distributions are obtained in the steady state approximation from the appropriate master equation or an equivalent diffusion equation. Energy transition probabilities are obtain from a classical gas- surface collision model using an interaction potential composed of an oscillating harmonic repulsion and a stationary attraction. Applications include prediction of adsorption and desorption rate constants, sticking and accommodation coefficients, sublimation and condensation rates, and boundary conditions for the Knudsen layer.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1972
Accession Number
AD0745034

Entities

People

  • James C. Keck
  • Patrick J. Pagni

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundaries
  • Desorption
  • Diffusion
  • Energy
  • Energy Bands
  • Energy Levels
  • Energy Transfer
  • Equations Of Motion
  • Fluid Mechanics
  • Frequency
  • Knudsen Number
  • Mechanics
  • Oscillation
  • Oscillators
  • Probability
  • Scattering
  • Steady State

Readers

  • Electrochemical Engineering/ Fuel Cell Technologies
  • Fluid Mechanics and Fluid Dynamics.
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.