Computer Simulation Studies of Bulk Reduction and Oxygen Migration in CeO₂−ZrO₂Solid Solutions

Abstract

Computer simulation techniques have been used to model cubic CeO 2 −ZrO 2 solid solutions in the whole composition range. Aspects related with the oxygen storage capacity of these materials are emphasized. The energetics of the Ce 4+ /Ce 3+ bulk reduction reaction as well as the activation energy for oxygen migration in the lattice are investigated and compared with the corresponding quantities in pure CeO 2 . It is found that even small additions of ZrO 2 decrease the bulk reduction energy of Ce 4+ to values comparable to those reported for surface reduction in pure CeO 2 . Activation energy calculations indicate an almost monotonic increase of oxygen mobility with increasing zirconia content.