Adsorption of Cu and Pd on α-Al2O3(0001) surfaces with different stoichiometries

Abstract

We report density functional theory calculations of the interaction of Cu and Pd with the (0001) surface of $\mathrm{\alpha -}{\mathrm{Al}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}.$ The interaction of those metals with the oxide surface varies from covalent-like for the aluminum rich surface to ionic-like for the oxygen terminated surface. Stoichiometric hydroxylation of the surface does not increase the metal–oxide interaction significantly. We suggest that defects created upon hydroxylation are the main mechanism to explain the observed metal wetting of the oxide.