Electrical conductivity and oxygen permeability of Ce0.8Sm0.2O2鈭捨?/sub>-PrBaCo2O5+未 dual-phase composites
- 作者：Ting Chena ; Hailei Zhaoa ; c ; hlzhao@ustb.edu.cn ; Zhixiang Xiea ; Linchang Fenga ; Xionggang Lub ; Weizhong Dingb ; Fushen Lia ; c
- 关键词：Composite ; Dual-phase ; Double-perovskite ; Membrane ; Oxygen permeation
- 刊名：International Journal of Hydrogen Energy
- 出版年：2012
- 期刊代码：42_03603199
- 类别：ch
- 出版时间：March, 2012
- 卷：37
- 期：6
- 页码：5277-5285
- 文件大小：2133 K
摘要
A novel dual-phase oxygen permeation membrane based on ion-conducting Ce0.8Sm0.2O2鈭捨?/sub> (SDC) and mixed conducting PrBaCo2O5+未 (PBCO) is presented. There is no obvious reaction between the two phases under preparation and oxygen permeation conditions. The percolative network of mixed conducting phase PBCO can be formed in SDC-PBCO composite when the ratio of PBCO is not less than 40聽vol.%. Above this threshold, the oxygen permeability of SDC-PBCO membrane increases with increasing SDC content. Compared with pure PBCO membrane, the oxygen permeability of percolative SDC-PBCO composites is improved due to the 3D diffusion ability of SDC, which can shorten the tortuosity of the oxygen diffusion path in layered PBCO. The maximum oxygen flux based on 0.6-mm-thick SDC-PBCO (6/4) is 2.38聽脳聽10鈭?聽mol聽cm鈭?聽s鈭? at 925聽掳C. The dependence of the oxygen permeation flux on the membrane thickness demonstrates that the bulk diffusion is the limiting step at thickness higher than 0.8聽mm and the surface exchange may play an important role when the thickness is below that. Incorporation of SDC into PBCO can not only improve the oxygen permeability but also enhance the structural stability. The SDC-PBCO (6/4) dual-phase membrane is a promising candidate for oxygen separation application.