Synthesis and characterization of nano-sized ceria powder via oxalate decomposition route

In this study, nano-sized powder of cerium (IV) oxide was prepared through the thermal decomposition reaction of Ce2(C2O4)3⋅ 10H2O. The thermal decomposition course was followed using differential thermal analysis–thermogravimetry (DTA–TG) techniques. Kinetic analysis of the dynamic TG curves was carried out, to obtain kinetic parameters for the decomposition of cerium oxalate into ceria, using three integral methods: Ozawa, Coats–Redfern, and Diefallah composite method. The produced ceria as well as calcined samples at different temperatures up to 950 °C were characterized using X-ray diffraction (XRD), Fourier transform infra-red (FT-IR) and transmission electron microscopy (TEM) techniques. The change in the structural and morphological properties with heat treatment was studied. Surface area measurement was carried out for the calcined samples at different temperatures to characterize the surface properties of the investigated samples. Electrical property as a function of temperature and frequency was measured to determine the conductivity as well as the conduction activation energy and to describe the conduction mechanism. The density functional theory (DFT) was used to describe the chemical bonding characteristics of the prepared compound. The obtained results were discussed to show the effect of heat treatment on the structural, morphological, superficial and electrical properties of ceria.

The geometry and electronic structure of Cerium (III) oxalate have been investigated using density functional theory (DFT) calculation. The figure shows the bond lengths and charges distribution. The optimized structure of Ce (III) complex shows that the cation interacts with three covalent bond and one coordinate oxygen atoms.Figure optionsDownload as PowerPoint slideHighlights
► Nano-sized ceria was prepared through thermal decomposition of oxalate precursor.
► The ceria was characterized by DTA-TG, XRD, FT-IR, TEM, BET and conductivity.
► Calcination effect on structure, morphology and superficial property was discussed.
► Kinetic analysis was carried out using dynamic TG curves.