Synthesis of nanocrystalline CeO2-Y2O3 powders by a nitrate-glycine gel-combustion process

In this work, the synthesis of CeO2-10 M01% Y2O3 powders by a nitrate-glycine gel-combustion route was investigated. Special attention was given to the influence of the glycine/metal ratio and calcination temperature on powder morphology. In contrast to the usual reported behavior, the best powder properties (crystallite size, 4.5-7 nm; specific surface area; 25-40 m(2)/g) were obtained for slow combustion processes with glycine/metal ratios of 1.5-2, whereas energetic reactions resulted in large crystallite and particle sizes. Furthermore, it was found that the crystallite size increases considerably even at moderate calcination temperatures (350-550 degreesC), showing the high reactivity of these nanopowders.