Synthesis of CeO2 nanoparticles by mechanochemical processing and the inhibiting action of NaCl on particle agglomeration

An alternative route for the synthesis of ceria nanoparticles by mechanochemical reaction with reactants containing crystalline water was proposed. The displacement reaction 2CeCl(3) (.) 6H(2)O(s) + 3Na(2)CO(3) (.) 10H(2)O(s) --> Ce-2(CO3)(3) (.) nH(2)O(s) + 6NaCl(s) + (42-n)H2O was induced in a mild manner during milling, and a subsequent calcination of the as-milled powder along with by-product NaCl led to the formation of ceria nanoparticles. It was suggested that the existence of by-product NaCl in as-milled powder could greatly decrease the aggregation of CeO2 particles during calcination, which benefited the formation of finer crystal ceria. TEM analysis of ceria obtained by calcining and subsequently washing has shown that the crystallite particle sizes of CeO2 were in the range of 40-70 nm and that only weak agglomeration of the nanoparticles was observed. (C) 2004 Elsevier B.V. All rights reserved.