Vibrational excitation of diatomic molecules interacting with metal surfaces: heating vs. cooling

Abstract

Vibrational excitation of diatomic molecules interacting with metal surfaces is investigated theoretically. Vibrational cooling of nitric oxide molecules in trapping-desorption process is explained satisfactorily by the simple calculation based on the kinetic theory of gas molecule-surface scattering and detailed balance relation. Vibrationally assisted sticking and vibrational heating of hydrogen molecules in associative desorption are explained by the coupled channel calculation based on the concept of a reaction path. It is suggested that the occurrence of vibrational heating (vibrational cooling) in desorption may be coordinated generally with the occurrence of vibrationally assisted (vibrationally hindered) sticking.