Electrochemical, catalytic and O<inf>2</inf>-permeation studies of iron-doped Barium Zirconates for membrane reactor applications

An Fe-doped Barium Zirconate perovskite (Ba0.9Fe 0.1Zr0.9O3-δ) is investigated for electrochemical and catalytic activity at 800oC via combination of gas effluent mass spectroscopy and electrochemical impedance spectroscopy (EIS). Results confirm competitive reaction rates for both CO2 reduction to CO and O2 under dry-gas conditions and CO oxidation to CO2 and H2 in the presence of steam. A combination of both p-type and n-type semiconduction behavior is suggested to explain the complex dependence of electrical conductivity upon individual gas species partial pressure. Separate gas permeation measurements confirm an O2 permeability of 9.52×10-12 mol.m-1.s-1.Pa-1, which is competitive with similarly reported zirconate-based perovskite materials. © The Electrochemical Society.