CHEMICAL-DYNAMICS AT THE GAS-SURFACE INTERFACE

We review recent progress in the understanding of the chemical dynamic s of gas-surface reactions. Such reactions can involve many dynamicall y distinct interactions, Our review begins by considering a number of these important elementary processes, dealing in turn with (1) the ini tial gas-surface interaction including translational, rotational, and vibrational energy exchange, the discussion of vibrational interaction s covering both direct vibrational excitation and vibrational relaxati on at surfaces; (2) the trapping or adsorption of atoms and molecules on the surface; and (3) the important elementary processes of surface diffusion and desorption. We conclude with a detailed look at two exam ples of gas-surface reactions, first summarizing what is now known abo ut the dissociative chemisorption of hydrogen at Cu surfaces (and the reverse process of recombinative desorption), Then we describe recent studies of direct gas-surface abstraction (or Eley-Rideal) reactions.