Theoretical study of the formation of oxide-supported metal particles: strength of the chemical glue as represented by transition metal ions at the metal-oxide interface

Abstract

The first step of the growth of a metal particle supported on an oxide has been theoretically simulated using the extended Huckel molecular orbital (EHMO) approach. The nucleation site at the oxide surface is modeled by a M(OH)x complex (x=3 and 5) and its interaction with either an isolated metal atom or a dimer theoretically calculated. The latter can approach the nucleation site with its internuclear axis either perpendicular or parallel to the surface. The stabilization energy, E s , expressed as the energy difference between the nucleation site and the metal (mono- or dimer) moieties at infinite separation and at bonding distance (2.25 A), has been plotted as a function of the original number of electrons at the nucleation site