Preparation of sandwich-structured Ce0.8Sm0.2O1.9-Sm0.6Sr0.4FeO3−δ ceramic membranes and its oxygen permeability

Abstract

Ce0.8Sm0.2O1.9-Sm0.6Sr0.4FeO3−δ (SDC-SSF) dual-phase ceramic membranes with sandwich-structure were fabricated by chemical etching method. By this method, SSF perovskite particles was etched from both sides of SDC-SSF dual phase membrane, and a SDC/SDC-SSF/SDC three-layer membrane with sandwich structure could be obtained. Crystal phase, microstructure and elemental distribution of SDC-SSF sandwich-structured membranes were investigated. XRD and SEM-EDS results demonstrate that SDC fluorite particles can be well reserved to form porous supports after leaching out SSF perovskite particles and a SDC-SSF dense functional layer was firmly sandwiched between two SDC porous supports, in which common shrinkage mismatch between thin film and porous support can be readily avoided. Thickness of SDC-SSF dense layer can be precisely controlled by changing the etching time. Oxygen permeation tests reveal that our SDC-SSF membranes exhibit an obviously improved oxygen permeation flux. Especially while cobalt-based catalysts were introduced into SDC porous supports, its oxygen flux could be further increase up to 0.95 ml·min−1·cm−2.