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

摘要

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 nm.