Effect of Zr4+ doping on the oxygen stoichiometry and phase stability of SrCo0.8Fe0.2O3 - δ oxygen separation membrane

W. Chen, Y. B. Zuo, C. S. Chen*, Louis Winnubst

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

19 Citations (Scopus)

Abstract

The effect of Zr doping in SrCo0.8Fe0.2O 3 - δ (SCF) membranes was investigated. The lattice parameter of SCF increased with the Zr content until 4 at.%, and then leveled off with further increase in the Zr content, revealing that the Zr solubility limit lies at ∼ 4%. The Zr doping resulted in an increase in oxygen stoichiometry (3 - δ) of SCF membranes especially at low oxygen partial pressure. The brownmillerite to perovskite phase transition was investigated by dilatometry in nitrogen (pO2 = 2 × 10- 3 atm). The phase transition temperature was lowered by Zr doping: 770 °C for undoped SCF and 710 °C for SCF doped with 4 at.% of Zr. The change in volume associated to the phase transition also became less pronounced for the Zr-doped samples. Compared to the undoped membrane, the Zr-doped SCF exhibited a somewhat lower oxygen permeability, but it remained well-permeable to oxygen at lower operation temperatures due to the stabilization of the perovskite structure.

Original languageEnglish
Pages (from-to)971-975
Number of pages5
JournalSolid state ionics
Volume181
Issue number21-22
DOIs
Publication statusPublished - 26 Jul 2010

Keywords

  • Brownmillerite
  • Order-disorder
  • Phase transformation
  • SCF

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