Sandwich-like symmetric dual-phase composite membrane with an ultra-thin oxygen separation layer and excellent durability

Abstract

The Zr0.84Y0.16O1.92-La0.8Sr0.2Cr0.5Fe0.5O3-δ (YSZ-LSCrF) dual-phase composite membrane is known to possess appreciable oxygen permeability and excellent stability under stringent operation conditions. In the present study, a sandwich-like symmetric YSZ-LSCrF membrane was prepared using the phase-inversion tape casting/lamination/sintering technique. The as-prepared membrane consisted of a 5 μm thick dense oxygen separation layer sandwiched between two 300 μm thick finger-like porous layers. To promote the surface oxygen exchange, the membrane was impregnated with Sm0.2Ce0.8O2-δ (SDC) nanoparticles. The oxygen permeation flux through the membrane was measured by exposing one side of the membrane to a flowing air stream and the other side to a flowing CO stream. An oxygen permeation rate of 1.95 ml (STP) cm–2 min–1 was obtained at 900 °C. The oxygen permeation rate increased with increasing temperature as expected, and the apparent activation energy for oxygen permeation was calculated to be 29.5 kJ mol–1. The membrane remained intact after the oxygen permeation measurement and thermal cycle stability test. The sandwich-like symmetric YSZ-LSCrF membrane with an ultra-thin oxygen separation layer demonstrated desired oxygen permeability and satisfactory durability, promising for membrane reactor applications. The preparation method developed in the present study can be applied to other ceramic membranes and devices requiring the similar sandwich-like symmetric structure.