A computational study of the structure of anion vacancy defects in the bulk and on the surfaces of ceria

Ceria is an important technological material that finds wide application as an oxygen storage component in heterogeneous oxidation catalysis. In these applications the removal of lattice oxygen results in two reduced Ce3+ centres whose location relative to the vacancy site has a profound influence on the vacancy formation energy. Here we present DFT calculations on the bulk and surface oxygen defect formation highlighting the distribution of structures that are thermally accessible in such a situation. We also demonstrate that the Ce3+ locations influence the barrier to oxygen anion migration.