The use of mixed-oxides containing CeO2as oxygen storage/release components is discussed with special focus on the applications of these materials in auto-exhaust catalytic converters. Ceria easily forms solid solutions with transition-metal/rare-earth oxides over a wide composition range. The incorporation of dopants like Zr4+, Pr3/4+, Tb3/4+into the cubic fluorite lattice of CeO2strongly affects the structural and energetic properties of the materials by lowering activation energy for oxygen migration and by increasing reducibility of the cerium cation. This augments both total and kinetic oxygen exchange between the solid and the gas phase under conditions typically encountered in real systems.