Publication Details (including relevant citation information):
H.L. Abbott and I. Harrison, Journal of Physical Chemistry A., 111, 9871 (2007)
Microcanonical transition state theory incorporating quantized surface vibrations is shown to be applicable to a benchmark system for gas-surface reaction dynamics, the activated dissociative chemisorption and associative desorption of hydrogen on Cu(111). The local hot spot model, defining 3 transition state parameters, predicts the diverse range of experimentally observed dissociative sticking and quantum state resolved desorption behavior and provides a statistical baseline for the gas-surface reactivity against which dynamical effects can be identified. Contrary to popular current notions, surface phonons are vital participants in the hydrogen chemisorption dynamics whereas molecular rotations are approximately spectator degrees of freedom at thermally accessible energies (i.e., for Er less than ~40 kJ/mol). The threshold energy for dissociative chemisorption of H2 on Cu(111) is E0 = 62 kJ/mol. Dynamical effects are identified that suggest the dissociative transition state is slightly early rather than late. A versatile theoretical framework capable of treating the dynamics of activated condensed phase reactions is validated.
Address (URL): http://