CH4 dissociation on Ni(111): a quantum dynamics study of lattice thermal motion

Abstract

Lattice thermal motion is of great importance because it has a significant effect on molecule activation on metal surfaces. Here, we present an in-depth quantum dynamics study of lattice thermal motion for methane dissociation on some static distorted Ni(111) surfaces based on an accurate, fourteen-dimensional potential energy surface fitted to ∼10⁵ab initio energy points. Our study reproduces the tendency that the sticking probability of ground state methane increases (decreases) as the lattice atom moves upward (downward), and thus represents the first validation of the applicability of the energy-shifting scheme to polyatomic molecular gas–surface reactions. Furthermore, we improve on the linear model proposed by Jackson's group and introduce a new model that is applicable to a broad range of surface temperatures.