Electrochemical, Catalytic and O 2 -Permeation Studies of Iron-Doped Barium Zirconates for Membrane Reactor Applications

Abstract

An Fe-doped Barium Zirconate perovskite (Ba 0.9 Fe 0.1 Zr 0.9 O 3-δ ) is investigated for electrochemical and catalytic activity at 800 o C via combination of gas effluent mass spectroscopy and electrochemical impedance spectroscopy (EIS). Results confirm competitive reaction rates for both CO 2 reduction to CO and O 2 under dry-gas conditions and CO oxidation to CO 2 and H 2 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 O 2 permeability of 9.52×10 -12 mol.m -1 .s -1 .Pa -1 , which is competitive with similarly reported zirconate-based perovskite materials.