等离子喷涂致密La0.6Sr0.4Co0.2Fe0.8O3-δ透氧膜氧传输行为的研究

Study on the oxygen transportation behavior of dense La0.6Sr0.4Co0.2Fe0.8O3-δ oxygen transport membrane prepared by plasma spraying technology

摘要:

本文采用超音速等离子喷涂(SAPS)和等离子物理气相沉积方法(PS-PVD)制备了结构致密的钙钛矿型(ABO₃)La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ(LSCF)透氧膜。利用氧程序升温脱附(O₂-TPD)、XPS等手段,比较了两种膜在200-900℃间氧物种在表面及体相中的传递变化情况。O₂-TPD结果显示：SAPS膜的物理吸附氧脱附量、化学吸附氧脱附量和晶格氧脱附量分别超过PS-PVD膜的2倍、3倍和6倍；而XPS结果显示：SAPS膜表面吸附氧与晶格氧O1s峰面积比也高于PS-PVD膜。以上结果表明SAPS膜对氧具有更好的吸附及解离能力、更多的本征氧空位及更高的空位生成能力。

Abstract:

Gas-tight perovskite La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ(LSCF)oxygen transport membranes were prepared by supersonic air-gas plasma spraying (SAPS) and low pressure plasma spraying-physical vapor deposition (PS-PVD). Surface exchange and bulk diffusion of the oxygen species of the two membranes were compared by the use of O₂-TPD and XPS. The O₂-TPD result shows the desorptions of the physical, chemical adsorbed oxygen and the lattic oxygen of the SAPS membrane were 2, 3 and 6 times respectively more than those of the PS-PVD membrane. The XPS result also shows a higher proportion of adsorbed oxygen of the SAPS membrane than that of the PS-PVD membrane. All the above results demonstrate that the SAPS membrane should has better adsorption and dissocation abilities on oxygen, and should also possesses more intrinsic oxygen vacancies and higher capacity of vancancy formation.