Sr1鈭?/sub>xCaxMoO3-Gd0.2Ce0.8O1.9 as the anode in solid oxide fuel cells: Effects of Mo precipitation
详细信息 查看全文
- 作者：Peng Xiao ; Xiaoming Ge ; Zhaolin Liu ; Jing-Yuan Wang ; Xin Wang
- 关键词：Solid oxide fuel cells ; Strontium molybdate ; Calcium doping ; Mo segregation ; Perovskite
- 刊名：Journal of Alloys and Compounds
- 出版年：25 February, 2014
- 年：2014
- 卷：587
- 期：Complete
- 页码：326-331
- 全文大小：1756 K
文摘
Calcium is incorporated into strontium molybdate to form Sr1鈭?/sub>xCaxMoO3 as an electronic conductor for solid oxide fuel cells (SOFCs). Metallic molybdenum was observed with the increasing content of Ca substitution for Sr in Sr1鈭?/sub>xCaxMoO3. Rietveld refinement reveals the phase transition from cubic to tetragonal perovskite structure, which implies its decreased thermodynamic stability under reducing conditions with increasing content of Ca. X-ray diffraction (XRD) and differential scanning calorimetry-thermo-gravimetric analysis (DSC-TGA) further prove that this Mo ex-solution is reversible. The electrochemical performances of Sr1鈭?/sub>xCaxMoO3 towards H2 and CH4 oxidation at 800 掳C are examined. The performance is improved in H2 atmosphere with the introduction of Ca, 330 mW cm鈭? of Sr0.5Ca0.5MoO3-Gd0.2Ce0.8O1.9 (GDC) vs. 280 mW cm鈭? of SrMoO3-GDC, which can be ascribed to the segregated Mo as the additional catalyst. However, carbon deposition is observed after exposure to CH4 at 800 掳C for both Sr0.7Ca0.3MoO3-GDC and Sr0.5Ca0.5MoO3-GDC, in contrast to the absence of carbon on SrMoO3-GDC.