Zhang Zhenbao, Zhou Wei, Chen Yubo, Chen Dengjie, Chen Jiawei, Liu Shaomin, Jin Wanqin, Shao Zongping
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry & Chemical Engineering, Nanjing Tech University , Nanjing 210009, P. R. China.
Department of Chemistry, Jinan University , Guangzhou 510632, P.R. China.
ACS Appl Mater Interfaces. 2015 Oct 21;7(41):22918-26. doi: 10.1021/acsami.5b05812. Epub 2015 Oct 6.
A novel method based on beneficial phase reaction for developing composite membranes with high oxygen permeation flux and favorable stability was proposed in this work. Various Ce0.8Sm0.2O2-δ (SDC) + SrCO3+Co3O4 powders with different SDC contents were successfully fabricated into membranes through high temperature phase reaction. The X-ray diffraction (XRD) measurements suggest that the solid-state reaction between the SDC, SrCO3 and Co3O4 oxides occurred at the temperature for membrane sintering, leading to the formation of a highly conductive tetragonal perovskite phase SmxSr1-xCoO3-δ. The morphology and elemental distribution of the dual-phase membranes were characterized using back scattered scanning electron microscopy and energy dispersive X-ray spectroscopy (BSEM-EDX). The oxygen bulk diffusivity and surface exchange properties of the materials were investigated via the electrical conductivity relaxation technique, which supported the formation of conductive phases. The SDC+20 wt % SrCO3+10.89 wt % Co3O4 membrane exhibited the highest permeation flux among the others, reaching 0.93 mL cm(-2) min(-1) [STP = standard temperature and pressure] under an air/helium gradient at 900 °C for a membrane with a thickness of 0.5 mm. In addition, the oxygen permeation flux remained stable during the long-time test. The results demonstrate the beneficial phase reaction as a practical method for the development of high-performance dual-phase ceramic membranes.
本工作提出了一种基于有益相反应的新方法，用于制备具有高氧渗透通量和良好稳定性的复合膜。通过高温相反应，成功地将各种不同Ce0.8Sm0.2O2-δ（SDC）含量的SDC + SrCO3 + Co3O4粉末制成膜。X射线衍射（XRD）测量表明，SDC、SrCO3和Co3O4氧化物之间的固态反应在膜烧结温度下发生，导致形成高导电四方钙钛矿相SmxSr1-xCoO3-δ。使用背散射扫描电子显微镜和能量色散X射线光谱（BSEM-EDX）对双相膜的形态和元素分布进行了表征。通过电导率弛豫技术研究了材料的氧体扩散率和表面交换性能，这支持了导电相的形成。在900℃、空气/氦气梯度下，对于厚度为0.5mm的膜，SDC + 20 wt% SrCO3 + 10.89 wt% Co3O4膜在其他膜中表现出最高的渗透通量，达到0.93 mL cm(-2) min(-1) [STP =标准温度和压力]。此外，在长时间测试中氧渗透通量保持稳定。结果表明，有益相反应是开发高性能双相陶瓷膜的一种实用方法。
