THIN-FILM, MIXED CONDUCTIVE MEMBRANES FOR OXYGEN SEPARATION

摘要

Dip coating of Bi1.35Y0.45Fe0.2O3-z-35 vol. % Ag mixed ionic-electronic conducting (MIEC) ceramics on porous MgO supports is a realistic method for making dense coatings. These MIEC devices are being developed under GRI funding for seperation of oxygen from air using a partial pressure oxygen differential on the two sides of the membrane as the driving force for diffusion of oxygen. Doping bismuth oxide-based cermets with Fe2O3 increased both the ambipolar conductivity and lowered the interfacial resistance. Doping with Fe2O3 decreased the creep resistance of the cermet and limits its use in pressure-driven systems to about 750 deg C. Future challenges for commercializing this technology are outlined.