Study of pr-doped ceria-based electrolytes for ITSOFC

Pr-doped ceria materials were synthesized by Pechini method using citric acid as chelating agent, and the resultant materials were examined for possible application as electrolyte in ITSOFC. The XRD patterns of Pr doped ceria with the formula Ce1-xPrxO2-delta (abbreviated as xCPO) showed that all the samples with x <= 35% were fluorite-type solid solutions. The Pr L-3-edge XANES profiles of xCPO after calcination at 700 degrees C and sintering at 1500 degrees C were similar to that of Pr6O11. For 30CPO, the Pr3+/(Pr3++Pr4+) molar ratio determined by XPS profile analysis was ca. 57%. These results implied that the number of oxygen vacancies created in the samples was lower than originally expected. Among the doped samples with x 5-40%, 30CPO gave the highest conductivity of 0.067 S/cm, which exceeded those of CGO and CSO. Moreover, with Mg co-dopant the conductivities were enhanced, while the contrary was seen with Ca co-dopant.