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% CeO2 phase and 88.52% Ce0.26Zr0.62(LaPr)0.12O2 solid solution phase were obtained under oriented attachment aging process. The rod-like CeO2 phase coexisted with spherical Ce0.26Zr0.62(LaPr)0.12O2 solid solution phase, which improved the surface area (64 m2/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 Ce0.35Zr0.55(LaPr)0.10O2 solid solution with homogenous phase structure was generated by Ostwald ripening aging process, exhibiting higher oxygen storage capacity (501 µmol O2/g) and H2 consumption per gram (1378.3 µmol H2/g).

Graphical AbstractHRTEM images of CZOA (a) and CZOA-a (b) (for CZOA, inset is a fast Fourier transform (FFT) analysis and for CZOA-a, inset is a fast Fourier transform (FFT) analysis)Figure optionsDownload as PowerPoint slide