Dissociative Chemisorption of Methane on Transition Metals

摘要

When brought into contact with a clean surface of a transition metal many simple molecules, whose constituent atoms are bound together in the gas phase with energies of several electron volts, rapidly dissociate into fragments which are then strongly bound to the metal surface. There are exceptions to this rule, however. Some types of molecules must pass over a measurable potential barrier before they may dissociate. This study is primarily an attempt to clarify the nature of the elementary excitations involved in surmounting this reaction barrier for a representative system: methane on transition metals. Our results are well described by a model in which excitation of the higher bending modes of methane molecules is necessary for chemisorption.