Cubic bismuth oxide (δ-Bi2O3) exhibits the highest reported oxide ion conductivity among binary oxides. Paired with the excellent electronic conductor (La0.8Sr0.2)0.99MnO3-δ (LSM), Tm-stabilised δ-Bi2O3 (BTM) and LSM form state-of-the-art ceramic composite oxygen transport membranes. The present contribution addresses the surface and bulk properties of the BTM-LSM materials system to determine the limiting factors for the oxygen permeation across the membrane. We seek to optimize the performance by improving the microstructure and varying the BTM/LSM volume ratio. To examine the potential of stabilized δ-Bi2O3 as a single-phase OTM, we introduce mixed conductivity in BTM by substituting some of the Tm with Pr. Flux measurements were performed as a function of temperature and oxygen partial pressure gradient and oxygen exchange coefficients were determined by means of oxygen isotope based approaches.
Emhjellen, L. K., Xing, W., Li, Z. & Haugsrud, R. (2022). Oxygen permeability and surface kinetics of composite oxygen transport membranes based on stabilized δ-Bi2O3. Journal of Membrane Science, Volume 660 (120875), 2-6. https://doi.org/10.1016/j.memsci.2022.120875.