Synthesis of CeO2 by thermal decomposition of oxalate and kinetics of thermal decomposition of precursor

Abstract

CeO2 was synthesized by calcining Ce2(C2O4)3·8H2O above 673 K in air. The precursor and its calcined products were characterized using thermogravimetry and differential scanning calorimetry, Fourier transform infrared spectra, X-ray powder diffraction, scanning electron microscopy, and UV–Vis absorption spectroscopy. The result showed that cubic CeO2 was obtained when the precursor was calcined above 673 K in air for 2 h. The UV–Vis absorption spectroscopy studies showed that superfine CeO2 behaved as an excellent UV-shielding material. The thermal decomposition of the precursor in air experienced two steps, which are: first, the dehydration of eight crystal water molecules, then the decomposition of Ce2(C2O4)3 into cubic CeO2. The values of the activation energies associated with the thermal decomposition of Ce2(C2O4)3·8H2O were determined based on the Starink equation.