Sol-gel synthesis and characterization of Al2O3-CeO2 composite nanopowder

An aqueous sol-gel method has been developed for preparation of an Al2O3-15 wt.% CeO2 composite nanopowder using metal chlorides and aluminum powder. The structural evolutions and morphological characteristics of the nanopowder were investigated by X-ray diffractometry, scanning electron microscopy, thermal analysis, Brunauer-Emmett-Teller surface area measurement and Fourier transform infrared spectroscopy. The results showed that crystallization of nanopowder occurred above 600 degrees C. The presence of the second phase suppressed the crystallization for both Al2O3 and CeO2. Al2O3-CeO2 nanopowder with a specific surface area of 56.1 m(2)/g and average particle size of 90 nm was obtained by calcination at 800 C. The activation energy of Al2O3-15 wt.% CeO2 nanocrystallite growth during calcination was measured to be 28.2 kJ/mol whereas that of Al2O3 was about 17.1 kJ/mol. (C) 2010 Elsevier B.V. All rights reserved.