Phase inversion tape casting and oxygen permeation properties of supported planar Zr0.84Y0.16O1.92–La0.8Sr0.2Cr0.5Fe0.5O3 − δ composite membrane

Abstract

The Zr0.84Y0.16O1.92 (YSZ)–La0.8Sr0.2Cr0.5Fe0.5O3−δ (LSCrF) composite membrane was prepared using the phase inversion tape casting method. Two slurries, one composed of YSZ and LSCrF powder, and the other composed also graphite, were used for preparation of the membrane. They were co-tape cast onto a Mylar sheet, and then immersed in a water bath for solidification into a green tape through phase inversion mechanism. After sintering at 1450°C in the air, the green tape was converted into a ceramic membrane. The sintered membrane possessed an asymmetric structure: a dense layer of thickness ~30μm and a finger-like porous support of thickness ~1mm. The membrane was further modified by applying a porous YSZ–LSCrF layer on its surfaces at the dense layer side and depositing Sm0.2Ce0.8O2 nano-particles on the inner surfaces of the support. The oxygen permeability of the as-prepared membrane was measured by exposing its dense layer side to air and the support side to CO at elevated temperatures. The membrane exhibited desired oxygen permeability under the given measurement conditions. An oxygen permeation flux as large as 2.4ml·cm−2·min−1 (STP) was observed at 900°C, which is comparable to the hollow fiber membrane of the same composition. Owing to its desired oxygen permeability and good stability, the supported planar YSZ–LSCrF membrane developed in the present study holds promise for applications in chemical reactors integrating oxygen separation and oxygen-consuming chemical reactions such as partial oxidation of methane (POM). The phase inversion tape casting method explored in the present study can be applied to the preparation of other ceramic membranes.