Ceria-based electrolytes with high surface area and improved conductivity for intermediate temperature solid oxide fuel cells

High-purity-doped ceria compounds Ce1-x RE (x) O2-delta (RE = Sm, Gd; 0 aecurrency sign x aecurrency sign 0.30) were synthesized by the Pechini method at 400 A degrees C. Nanostructured products of crystallite size 5-11 nm were obtained, presenting a single fluorite cubic phase and high surface area values in the range of 75-110 m(2)g(-1). Dense ceramic products with a relative density of 96-98 % resulted after sintering at 1450 A degrees C. Impedance spectroscopy was used to study the conductivity of these compounds in the temperature range of 200-750 A degrees C. Between 600 and 730 A degrees C, the compounds with x = 0.15, 0.20 show conductivities on the order of 10(-1) Scm(-1), with activation energies between 0.9 and 1.1 eV. Surface areas and conductivity values were found to be comparable with the highest values reported in the literature for similar compounds.