Ab lnitio Molecular Dynamics Study of Dissociative Chemisorption and Scattering of CO2 on Ni(100): Reactivity, Energy Transfer, Steering Dynamics, and Lattice Effects

摘要

The dissociative chemisorption of polyatomic molecules on metal surfaces has attracted much interest in recent years due to their industrial and fundamental importance. Comparing with extensively studied systems such as methane and water, however, dissociative chemisorption of CO2 which is important for CO2 activation, has so far received scant attention. We recently reported vibrational enhancement of the dissociative chemisorption of CO, on a rigid Ni(100) surface using a nine-dimensional potential energy surface (PES) based on a large number of density functional theory calculations. However, that PES is incapable of describing the lattice motion and energy transfer between this heavy molecule and the surface. To overcome these limitations, we present here ab initio molecular dynamics results for CO2 scattering and dissociation. In addition to formation of adsorbed O and CO, CO2 is found to have a large trapping probability in a chemisorption well, along with a substantial amount of energy loss to surface phonons. The lattice and dynamical steering effects are found to be quite different from what have been observed for direct dissociative chemisorption of methane and water.