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Abstract: The kinetic model of exoergic surface reactions developed in a previous contribution [M. Tomellini, Surf. Sci. 577 (2005) 200] has been extended to include multiquantum processes of vibrational energy transfer to the solid. It is shown that, under quasi-steady state conditions, the flux of adsorbing atoms leads to overpopulation of the adatom vibrational ladder with respect to the Boltzmann distribution and to enhanced recombination rates. By means of the associative model for adatom recombination, the vibrational populations have been estimated from experimental data on the kinetics of D-adatoms abstraction by gas H-atoms at Pt(111), Pt(110), Ni(100) and Cu(111) surfaces. These populations have been found to be hyperthermal and the shape of the energy distribution functions approximated by the Treanor equation. The impact of the interplay between energy dissipation and diatom formation on the reaction rate, has also been analysed and discussed. [Copyright &y& Elsevier]

It is shown that a vibrational non-equilibrium model of the chemisorption process can be employed for interpreting experimental data on adsorption-stimulated desorption. Further analysis of chemisorption rates, on a variety of substrates, also leads to the conclusion that desorption can be stimulated by the adsorption process, which determines an enhancement of the population of the upper bound vibrational level of the adspecies. The presence of this stimulation is revealed by a significant modification of the adsorption kinetics with respect to those expected under Boltzmann equilibrium conditions. An inverse correlation between rates of desorption and rates of vibrational relaxation of the adspecies stems from this analysis. A decrease of the relaxation rates with increasing surface coverage is also obtained for all the systems investigated. [Copyright &y& Elsevier]