Role of step sites on water dissociation on stoichiometric ceria surfaces

Abstract

The adsorption and dissociation of water on CeO 2(111), CeO 2(221), CeO 2(331), and CeO 2(110) has been studied by means of periodic density functional theory using slab models. The presence of step sites moderately affects the adsorption energy of the water molecule but in some cases as in CeO 2(331) is able to change the sign of the energy reaction from endo- to exothermic which has important consequences for the catalytic activity of this surface. Finally, no stable molecular state has been found for water on CeO 2(110) where the reaction products lead to a very stable hydroxylated surface which will rapidly become inactive. © 2012 Springer-Verlag.