Preparation of CeO2 Nanopowders by Hydrolysis and Oxidation of Cerium Carbide

An effective route for the synthesis of CeO2 nanopowders on a large scale was presented. High―quality CeO2 nanopowders composed of nanoparticles with size of 3―5 nm were prepared by hydrolysis and oxidation of cerium carbide. The experimental variables which can tune the BET surface area of CeO2 nanopowders, including hydrolysis reaction temperature, reaction time, as well as feed ratio of cerium carbide, were systematically. Experimental results indicate that the lower hydrolysis temperature (around room temperature), higher feed ratio (1:20 (g/mL) ), and proper reaction time (18 h) can product CeO2 nanopowders with higher surface area. The intermediate outcome Ce(OH)3 and aimed product CeO2 obtained with the optimized experimental variables (hydrolysis of cerium carbide powder at constant temperature (30 par; for 18 h in the suspension with feed ratio of 1:20 (g/mL) and dried at 80 or 4 h in the air) were characterized by X―ray diffraction (XRD), transmission electron microscope (TEM), selected area electron diffraction (SAED), and UV―visible absorption spectrometer. It is found that the Ce(OH)3is composed of a large quantity of rodlike nanostructures with length of 50―100 nm and diameter of 5―20 nm and the CeO2 nanopowders have higher UV―Vis absorbance property. Furthermore, the CeO2 nanopowders possess fine CO catalytic performance.