Synthesis of nano-sized ceria (CeO2) particles via a cerium hydroxy carbonate precursor and the effect of reaction temperature on particle morphology

Cerium oxide (ceo2) or ceria has been shown to be an interesting support material for noble metals incatalysts designed for emission control, mainly due to its oxygen storage capacity. ceria nanoparticleswere prepared by precipitation method. the precursor materials used in this research were cerium nitratehexahydrate (as a basic material), potassium carbonate and potassium hydroxide (as precipitants). themorphological properties were characterized by high resolution transmission electron microscopy(hrtem), scanning electron microscopy (sem) and x-ray diffraction (xrd), fourier transforminfrared spectroscopy (ftir) and uv-vis spectrophotometer. xrd results showed face centered cubicceo2 nanoparticles for annealed nanoparticles at 1000°c. sem measurement showed that by increasingthe calcinations temperature from 200 to 600°c, the crystallite size decreased from 90 to 28 nm. thesem results showed that the size of the ceo2 nanoparticles decreased with increasing temperature. theparticle size of ceo2 was around 25 nm as estimated by xrd technique and direct hrtem observation.sem and tem studies showed that the morphology of the prepared powder was sphere-like with anarrow size distribution. the sharp peaks in ftir spectrum determined the purity of ceo2 nanoparticlesand absorbance peak of uv-vis spectrum showed the small band gap energy of 3.26 ev.