Structural design of oxide ion conductive membranes for efficient oxygen separation from air

利用混合导电钙钛矿型氧化物进行氧分离，作为一种经济有效、环境友好的富氧空气制备方法，受到了人们的广泛关注。这项技术的一个主要优点是可以通过氧气浓度梯度将氧气从空气中分离出来。不需要任何电极和外部施加电压。在本项目中，我们重点研究了具有良好透氧性能和稳定性的铁基钙钛矿型氧化物，如Ba0.95La0.05FeO_3(BLF)。我们发现，通过沉积氧脱附层来控制膜的结构可以显著提高膜的透氧性能。氧脱附层的组成也是影响氧渗透的因素。以稳定同位素18O2为示踪剂的二次离子质谱仪(SIMS)分析揭示了氧在BLF膜中的渗透机理。

Oxygen separation using mixed-conducting perovskite-type oxides have been attracting much attention as a cost-effective, environmentally benign method to produce oxygen-enriched air. One major advantage of this technology is that oxygen can be separated from air by oxygen concentration gradients. Any electrodes and external applied voltages are not required. In this project, we focused on Fe-based perovskite-type oxides such as Ba0.95La0.05FeO3(BLF) that shows good oxygen permeation properties and stability. We found that controlling the membrane structure by depositing oxygen desorption layers significantly improves the oxygen permeation properties. The composition of the oxygen desorption layers was also influential factors for oxygen permeation. The SIMS (Secondary Ion Mass Spectrometry) analysis using stable isotope 18O2 as a tracer revealed the oxygen permeation mechanism in BLF membranes.