La0.2Sr0.8Fe0.8Ta0.2O3 (-) (delta) based thin film membranes with surface modification for oxygen production

Abstract

High temperature dense ceramic membranes made from mixed ionic/electronic conducting perovskite ceramics represent a high potential as a reliable source for oxygen and syngas production. In this work, La0.2Sr0.8Fe0.8Ta0.2O3 − δ based thin film perovskite system was evaluated, addressing the effect of structural surface modification on oxygen permeation rates. Membranes with ~ 20 μm thick dense functional layer and varying surface area on permeate side were fabricated by a dip coating technique. Oxygen permeation was measured at temperatures between 800 and 1000 °C by using varying partial pressure of O2 as a driving force. Maximum O2 flux values of ~ 5.8 and ~ 8.7 ml·cm− 2·min− 1 were recorded for smooth and structured permeation surfaces, respectively. This indicates that the surface roughness, which corresponds to an increase in surface area at the permeate side; can lead to a significant improvement in oxygen permeation rates reaching ~ 50% at 1000 °C.