Scandium-doped barium ceria ferrites-based composite mixed conducting hollow fiber membranes for H2 and O2 permeation

BaCeO3-based ceramics are a unique class of perovskites that exhibit protonic and oxygen ionic conduction, which are ideal for high temperature hydrogen separation applications. This work features Sc-doped BCFe composites with nominal composition of BaCe0.70Fe0.30-xScxO3−δ (BCFSc) (x = 0, 0.05, 0.1, 0.15, and 0.2) that exhibit enhanced thermal, chemical, and mechanical stability. The BCFSc20 (x = 0.20) hollow fiber membranes demonstrated the highest hydrogen and oxygen fluxes among the Sc-doped composites of up to 0.32 and 0.20 mL min−1 cm−2, respectively, at 1000 °C. The BCFSc20 hollow fibers also displayed excellent stability under the hydrogen and oxygen permeation environments, while the permeation performance of the other BCFSc samples with low Sc content gradually deteriorated over the 120-h stability test.