Structures and energies of iron promoted γ-Al2O3 surface: A computational study

The structure and energy of iron promoted γ-Al2O3 surface have been investigated in the framework of spin-polarized density functional theory using periodic slab model. It is found that the substitution of surface Al3+ by Fe3+ is thermodynamically accessible, and the promoted surfaces become metallic in nature. Full substitution of Al3+ by Fe3+ forms monolayer Fe2O3 surface. H2O adsorption leads to reconstruction of surface structures. On the basis of the computed H2O adsorption energies, the hydroxylated Fe2O3 oxide layer surface is found to be more easily dehydrated than the hydroxylated γ-Al2O3 surface.