Ultrasonic–Assisted Co–Precipitation Method of Preparation of Nanocomposites in The Al2O3–TiO2–ZrO2 System: Characterization and Microsturcture


School of Metallurgy & Materials Engineering, Iran University of Science & Technology


Recently, the Al2O3–TiO2–ZrO2 system has found valuable applications, particularly, as a support for NOx
storage–reduction (NSR) catalysts. Nanocomposite powders were prepared from the co-precipitation method
in inorganic precursors. The behaviors of mixed oxide nanoparticles under ultrasonic irradiation, such as
dispersion, and crushing were studied. Phase transformations, crystallite size, and microstructure of the
mixed oxides were investigated by STA (DTA/TG), FTIR, XRD, and SEM. XRD studies showed that
zirconium titanate (ZT) is main phase, and the crystallite size varies with the final calcination temperature,
and ultrasonic irradiations. SEM observations revealed that the calcination temperature strongly influences
the morphology of prepared mixed oxides. The results showed that the inorganic nanoparticles in the
aqueous solution can be redispersed more effectively by ultrasonic irradiation than by conventional stirring.
The average crystallite sizes of the ZT particles heat treated at 1200 °C for 2 h were in the range of 47-85