Synthesis of nano-sized crystalline oxide ion conducting fluorite-type Y2O3-doped CeO2 Using perovskite-like BaCe0.9Y0.1O2.95 (BCY) and study of CO2 capture properties of BCY

Formation of nano-sized Y2O3-doped CeO2 (YCO) was observed in the chemical reaction between proton conducting Y2O3-doped BaCeO3 (BCY) and CO2 in the temperature range 700-1000 degrees C, which is generally prepared by wet-chemical methods that include sol-gel, hydrothermal, polymerization, combustion, and precipitation reactions. BCY can capture CO2 of 0.13 g per ceramic gram at 700 degrees C, which is comparable to that of the well-known Li2ZrO3 (0.15 g per ceramic grain at 600 degrees C. Powder X-ray diffraction (PXRD), energy dispersive X-ray analysis (EDX), laser particle size analysis (LPSA), scanning electron microscopy (SEM), transmission electron microscopy(TEM), and ac impedance spectroscopy were employed to characterize the reaction product obtained front reaction between BCY and CO2 and subsequent acid washing. PXRD study reveals presence of fluorite-like CeO2 (a = 5.410 (1) angstrom) structure and BaCO3 in reaction products. TEM investigation of the acid washed product showed the formation of nano-sized material with particle sizes of about 50 rim. The electrical conductivity of acid washed product (YCO) in air was found to be about an order higher than the undoped CeO2 reported in the literature. (C) 2007 Elsevier Inc. All rights reserved.