Effects of Al content on the oxygen permeability through dual-phase membrane 60Ce0.9Pr0.1O2--40Pr0.6Sr0.4Fe1-Al O3

Ceramic dual-phase oxygen transport membranes with the composition of 60 wt% Ce0.9Pr0.1O2-δ-40 wt%Pr0.6Sr0.4Fe1-xAlxO3-δ (x = 0.05, 0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 1.0) (60CPO-40PSF1-xAxO) based on 60Ce0.9Pr0.1O2-δ-40Pr0.6Sr0.4FeO3-δ doped Al was successfully synthesized through a modified Pechini method. Crystal structure, surface microtopography and oxygen permeability are investigated systematically. The cell parameters of perovskite phase first increased and then decreased with the increase of Al content, which is related to the radius of the Al3+ and the formation of impurity phase. As x ranges from 0.1 to 0.8, the oxygen permeability of the materials first increases and then decreases, and the maximum value of oxygen permeation rate for 60CPO-40PSF1-xAxO membranes with 0.4 mm thickness at 1000 °C is 1.12 mL min−1 cm−2 when x = 0.4. XRD measurements revealed high temperature stability and CO2-tolerant property of the dual-phase composites. The partial replacement of Fe3+/Fe4+ by Al3+ causes the material not only to exhibit good stability, but also to increase the oxygen permeability of the membranes.