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.