Oxygen permeation and stability of Ba_0.9Co_0.7Fe_0.2Nb_0.1O_3?¦Ä membrane with three-layer structure

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• 作者：Peng Zhang ; Shidong Song ; Minfang Han ; ^{hanminfang@sina.com}
• 关键词：Three layer structure ; Oxygen permeation membrane ; Stability ; Mixed conductor
• 刊名：Materials Letters
• 出版年：2013
• 出版时间：1 August, 2013
• 年：2013
• 卷：104
• 期：Complete
• 页码：1-4
• 全文大小：1161 K

文摘

Oxygen permeation membrane with mixed ionic and electronic conductivities is a very attractive technology for the production of oxygen of high purity in an energy- and cost-efficient way. Recently, Ba_0.9Co_0.7Fe_0.2Nb_0.1O_3?¦Ä perovskite with A-site deficiency has drawn a lot of attentions for its high oxygen permeation flux and good stability. In this work, for further improving the oxygen permeation performance of Ba_0.9Co_0.7Fe_0.2Nb_0.1O_3?¦Ä membrane, a three-layer structure consisting of a dense thin film and two porous support layers is applied. The three-layer Ba_0.9Co_0.7Fe_0.2Nb_0.1O_3?¦Ä membrane achieved an oxygen permeation flux as high as 3.93 ml cm^?2 min^?1 at 900 ¡ãC, which is nearly 1.5 times higher than that of the conventional membrane with the same overall thickness. By increasing the flow rate of sweep gas, the oxygen permeation flux of the three-layer membrane was further enhanced up to 4.85 ml cm^?2 min^?1. A short term stability test of 100 h was conducted and no obvious degradation of the oxygen permeation performance was observed, which indicated that Ba_0.9Co_0.7Fe_0.2Nb_0.1O_3?¦Ä membrane with a three-layer structure could be very promising for the application in an oxygen generator.