Characterization of Samarium Doped Ceria Powders having High Specific Surface Area Synthesized by Carbon-assisted Spray Pyrolysis

摘要

Spherical samarium doped ceria (Ce0.8Sm0.2O1.9, SDC) powders having high specificsurface area (SSA) were successfully synthesized by carbon-assisted spray pyrolysis (CASP).Saccharides, such as monosaccharides and disaccharides, or organic acids were used as carbonsources. The physical and chemical properties of these powders were investigated using X-raydiffraction (XRD), scanning electron microscopy (SEM), Thermo gravimetry-Differential ThermalAnalysis (TG-DTA), and BET. Decarbonized powders obtained by this method exhibit sphericalmorphologies and nano- and submicron-sizes. The SSA of SDC obtained from CASP was more thanseven times higher than that obtained from conventional spray pyrolysis (CSP). The SSA of thedecarbonized SDC powders obtained by calcination at 900 °C was estimated to be approximately 70m2/g by using the BET method. The relative density of SDC obtained from CASP was higher than thatobtained from CSP. The relative density of the SDC pellet was highest (96 %) when it was sintered at1400 °C.