Oxygen permeation and stability of Zr_0.8Y_0.2O_0.9‒La_0.8Sr_0.2CrO_3-δ dual-phase composite

Abstract

A tubular membrane made of Zr_0.8Y_0.2O_1.9 (60 vol%) and ${\rm{La}}_{{0.8}} {\rm{Sr}}_{{0.2}} {\rm{CrO}}_{{3 - \delta }}$ was prepared by a standard ceramic process. Oxygen permeation through the membrane tube was examined by exposing its outer shell to air and sweeping its inner wall with pure helium or CO balanced with helium. An oxygen flux of 9.2×10⁻⁹ mol cm⁻² s⁻¹ was measured at 950°C under air/He gradient, and a larger flux of 3.2×10⁻⁸ mol cm⁻² s⁻¹ at 930°C under air/CO gradient. The membrane tube was found to exhibit excellent stability under highly reducing atmosphere and elevated temperatures. The oxygen permeation rate is likely to be increased through the modification of the surface and reduction of the membrane thickness.