Modeling basic components of solid oxide fuel cells using density functional theory: Bulk and surface properties of CeO2

In this paper, the structural and electronic properties of CeO2 are studied using conventional and hybrid density functional theory. A computational protocol, based on the parameter-free hybrid functional PBE0 coupled with a 4f in-valence basis set for Ce atoms based on a 28 electrons small core pseudopotential is able to reasonably reproduce both structural and electronic experimental data. Such a protocol is then applied to the modeling of true 2-D periodic CeO2 slabs of non polar low-index surfaces. The obtained results show that the (111) surface is more stable than the (110) one (0.73 vs 0.81 J/m2), with a substantial rumbling in the outermost planes of this latter. Finally, as a first step toward reactivity at CeO2 surfaces involved in solid oxide fuel cells, the importance of electrostatic effects in the adsorption of chemical species such as CO is presented. These results will allow for a detailed study of catalytic reactions at ceria surface.