Non-equilibrium vibrational kinetics and 'hot atom' models in the recombination of hydrogen atoms on surfaces

Non-equilibrium vibrational kinetics as recently developed for adlayers is applied to experimental data on H-atom recombination and abstraction at sol id surfaces. This model allows one to fit vibrational and translational ene rgy distribution functions of the excited diatoms leaving the surface. Eley -Rideal and Langmuir-Hinshelwood mechanisms involving vibrationally excited adatoms are presented together with a criterion for establishing their rel ative contribution to the total reaction rate. Analogies of this multilevel 'hot atom' (HA) model with recently employed two and three levels HA kinet ic schemes are presented and discussed. (C) 2001 Elsevier Science B.V. All rights reserved.