Mechanism of Near-Threshold Stimulated Desorption of Protons from Transition-Metal Surfaces

Abstract

The mechanism for near-threshold electron- and photon-stimulated desorption of protons from transition-metal surfaces has been investigated by using configuration-interaction techniques on finite clusters. The calculations indicate that the protons arise from repulsive states involving double excitations from the metal-hydrogen bonding orbitals and suggest that the process may occur via a surface predissociation mechanism. The calculations are compared to experimental electron-stimulated-desorption results for $\mathrm{Ni}〈111〉$.