Computer modeling of surfaces and defects on cerium dioxide

摘要: Abstract The structures and relative stabilities of several CeO2 surfaces, anion vacancy centers formed on them, are studied using theoretical molecular mechanics methods. In agreement with previous literature work, the compact (111) surface appears as most stable one; it is followed by (110), (211) (which spontaneously reconstructs into a stepped configuration) (100). latter case deserves consideration; intrinsic instability predicted for simple model, which led to being discarded in works, disappears once its oxygen content properly adjusted. Formation defects seems more difficult (actually, not easier than generation bulk Ce2O3) others. This suggests that different surfaces might be discernible appropriate redox experiments. Anion pairs, probably important O2 uptake release processes, seem form surface. Possible implications these results reactivities ceria materials having exposed discussed. simulations reproduce ∼ 10% error experimental modulus CeO2; they predict also cubic phase Ce2O3, lattice constant 11.16 A very good recent reports.