Thermal decomposition kinetics of precursor of CeO2 nanocrystalline prepared by precipitation method

With Ce(NO3)3&middot6H2O and (NH4)2 CO3&middotH2O as raw materials, the precursor Ce2(CO3)3&middotH2O of CeO2 nanocrystalline was prepared by chemical precipitation method using a little amount of PEG4000 as surfactant. The technique of DSC/TG and XRD were used to study the process of thermal decomposition. In particular, the differential thermal analysis curves were measured at different temperature raising-rate in air atmosphere for decomposition of the precursor of CeO2 nanocrystalline by thermal analysis apparatus. The kinetics process was studied with the method of Kissinger-Akahira-Sunose(KAS) and Coats-Redfern. The results show that the decomposition of Ce2(CO3)3&middotH2O consists of two steps. The active energy of the main step is 105.51 kJ/mol, the reaction order is 2, and the frequency factor is 3.61. The possible conversion functions for the decomposition of the precursor of CeO2 nanocrystalline is Anti-Jander equation and the mechanism of reaction is three-dimensional diffusion.