Preparation of nano-sized CeO2 by mechanochemical reaction of cerium carbonate with sodium hydroxide

The preparation of nano-sized CeO2 powder by mechanochemical reaction of hydrate cerium carbonate with sodium hydroxide and subsequent heat treatment was studied using X-ray diffraction, differential thermal and thermo gravimetric analyses, and transmission electron microscopy. It was found that the mechanochemical reaction process can be divided into two steps: the first step is the multi-phases mechanochemical reaction of cerium carbonate with NaOH to form amorphous cerium hydroxide, the second step is the crystallization of Ce(OH)(4) to form crystalline CeO2-2H(2)O under a quasi-hydrothermal synthesis condition caused by the mechanical ball-milling. The CeO2 powder obtained from as-milled Ce-2(CO3)(3).8H(2)O+NaOH following water washing and heat treatment at 800degreesC appears clearly separated monodisperse nano-size particles: their crystal sizes are from 10 to 20 nm and the medium size aggregated particles is 0.21 mum. (C) 2003 Elsevier B.V. All rights reserved.