Phase Stability and Permeation Behavior of a Dead-End Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-delta) Tube Membrane in High-Purity Oxygen Production
Phase Stability and Permeation Behavior of a Dead-End Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-delta) Tube Membrane in High-Purity Oxygen Production
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DOI：
10.1021/cm2018086
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发表时间：
2011-10
影响因子：
8.6
通讯作者：
Fangyi Liang;Heqing Jiang;Huixia Luo;J. Caro;A. Feldhoff
中科院分区：
文献类型：
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作者：
Fangyi Liang;Heqing Jiang;Huixia Luo;J. Caro;A. Feldhoff
研究了Ba0.5Sr0.5Co0.8Fe0.2O3Ba0.5Sr0.5Co0.8Fe0.2O3BSCF(BSCF)死端管膜在950℃和750℃下长期制氧的相稳定性和氧渗透行为。在950℃时，−δ膜具有良好的长期相稳定性和稳定的氧通量。然而，在750℃的中温，氧气渗透通量和氧气纯度都持续下降。这一行为与两个第二相的形成有关，一个是六方钙钛矿结构的Ba0.5±xSr0.5±xCoO_3−δ，另一个是三方结构的混合氧化物Ba1-xSrxCo2-yFeyO5，它们在立方BSCF钙钛矿陶瓷膜中随氧气的动态流动而变化。相形成所产生的拉应力会导致膜上出现裂纹，这会破坏渗透的氧气的纯度。在强氧化条件下，立方BSCF钙钛矿在中温区(750°C)的部分降解更为明显。
Phase stability and oxygen permeation behavior of Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) dead-end tube membranes were investigated in long-term oxygen production at 950 and 750 °C. At 950 °C, the BSCF tube membranes exhibit good long-term phase stability and a stable oxygen permeation flux. However, at the intermediate temperature of 750 °C, both the oxygen permeation flux and the oxygen purity decrease continuously. This behavior is related to the formation of two secondary phases that are a hexagonal perovskite, Ba0.5±xSr0.5±xCoO3−δ, and a trigonal mixed oxide, Ba1–xSrxCo2–yFeyO5, that evolved in the ceramic membrane made of cubic BSCF perovskite during the dynamic flow of oxygen through it. Tensile stress as a result of phase formation causes the development of cracks in the membrane, which spoil the purity of the permeated oxygen. The partial degradation of cubic BSCF perovskite in the intermediate temperature range (750 °C) was more pronounced under the strongly oxidizing conditions on the oxygen supply (fe...