| Summary: | 碩士 === 輔仁大學 === 物理學系 === 97 === To find the feasibility of using proton conductors as electrolytes in solid oxide fuel cells (SOFCs), the temperature-dependent x-ray diffracto- meter was employed to investigate the thermal stability of proton- conducting ceramics in CO2 environment. Ba(Zr0.8-xCexY0.2)O2.9 (BZCY) ceramic powders, with x=0, 0.1, 0.2, 0.3 and 0.4, were synthesized by glycine-nitrate process, and the single crystalline phase was obtained after calcining at 1300 oC. By in situ XRD measurement, the BZCY powders exhibit good thermal stability in CO2 environment below 900 oC for x=0, 0.1 and 0.2, while the other powders reacting with CO2 produced BaCO3 and decomposed obviously above 600 oC. The orthorhombic-hexagonal structure transition of BaCO3 was also observed in the region of 810~850 oC. For x≦0.4, the simple cubic structure of BZCY was confirmed by XRD spectra taken at room temperature, and the lattice constant of each sample, which decreased with increasing Zr content, was carried out. The kinetic stability of x≦0.2 samples was verified after a long duration of CO2 exposure.
|
|---|
