Structure and properties of cerium zirconium mixed oxide prepared under different precipitate aging processes

Oriented attachment and Ostwald ripening are two aging mechanisms of precipitation particles which may result in different crystallization mechanism of precipitates during the aging process. In this work, the effects of different aging process on the structure and properties of cerium zirconium mixed oxides were investigated. The results indicated that the mixed structure of 11.48% CeO 2 phase and 88.52% Ce 0.26 Zr 0.62 (LaPr) 0.12 O 2 solid solution phase were obtained under oriented attachment aging process. The rod-like CeO 2 phase coexisted with spherical Ce 0.26 Zr 0.62 (LaPr) 0.12 O 2 solid solution phase, which improved the surface area (64 m 2 /g) and pore volume (0.32 mL/g) of cerium zirconium mixed oxides after 1000 °C 4 h thermal treatment. However, through controlling the aging process, the Ce 0.35 Zr 0.55 (LaPr) 0.10 O 2 solid solution with homogenous phase structure was generated by Ostwald ripening aging process, exhibiting higher oxygen storage capacity (501 µmol O 2 /g) and H 2 consumption per gram (1378.3 µmol H 2 /g).