A New Series of Sr(Co,Fe,Zr)O3-δ Perovskite-Type Membrane Materials for Oxygen Permeation

Abstract

A new series of SrCo0.4Fe0.6-xZrxO3-δ (0 ≤ x ≤ 0.2) and SrCo0.95-xFexZr0.05O3-δ (0.1 ≤ x ≤ 0.8) oxides were synthesized by the solid-state reaction method. The incorporation of Zr and its effect on the crystal chemistry, oxygen permeation, and structural stability of SrCo0.4Fe0.6-xZrxO3-δ have been investigated. Formation of the solid solutions with the cubic perovskite-type structure was found in the SrCo0.4Fe0.6-xZrxO3-δ oxide system in the range of 0 ≤ x < 0.1. The incorporation of the proper content of Zr into SrCo0.4Fe0.6O3-δ suppressed the oxygen loss at high temperature and could stabilize the cubic structure of perovskite in a low oxygen partial pressure atmosphere, while the oxygen permeability of SrCo0.4Fe0.6-xZrxO3-δ membranes decreased with increasing Zr content. A total of 5 mol % of Zr cation dissolution was considered to be enough for the structural stability without deleteriously affecting the oxygen flux. Meanwhile, an investigation of the effect of the Co content on the oxygen permeation...