Hybrid Molten/Solid In2O3-Bi2O3 Oxygen Ion Transport Membranes

The hybrid molten/solid In2O3 - 30-48 wt.% Bi2O3 oxide materials were studied with respect to their transport properties. The conductivities, oxygen ion transport numbers and oxygen permeation fluxes have been measured by using the four-probe DC, volumetric measurements of the faradaic efficiency and gas flow techniques, respectively. We show that the oxygen permeability of the hybrid molten/solid In2O3-Bi2O3 materials is comparable to that of the state-of-the-art oxygen ion transport membrane materials. In the ranges of temperatures between 820-900 °C and thicknesses 1.2-3.4 mm used in the present study, the overall oxygen permeation kinetics was controlled by chemical diffusion. The hybrid molten/solid materials show promise for use as ion transport membranes for oxygen separation from air.