Phase and microstructural characterizations for Ce0.8Gd0.2O2-δ-FeCo2O4 dual phase oxygen transport membranes

F. Zeng*, Jürgen Malzbender, Stefan Baumann, Manja Krüger, Louis Winnubst, Olivier Guillon, Willi Meulenberg

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

1 Citation (Scopus)
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Abstract

Dual phase oxygen transport membranes were prepared via solid state reaction at 1200 ℃. The sintered membranes were characterized via X-ray diffraction, back scattered electron microscopy and electron backscatter diffraction, and associated with image analysis and calculations to quantify phase compositions and microstructural features including volume fractions, grain sizes, and contiguity. The characterizations reveal a multi-phase system containing Ce1-xGdxO2-δ’ (x ≈ 0.1) (CGO10), and FeyCo3-yO4 (0.2 < y < 1.2) (FCO), CoO and Gd0.85Ce0.15Fe0.75Co0.25O3 (GCFCO) in the sintered membranes. In addition, a novel model is utilized to assess the evolution of the ambipolar conductivity with respect to microstructural features. Both experimental and calculated results indicate that if the grain sizes of all phases in the composites are similar, the optimal ambipolar conductivity is reached with a volume ratio of ionic conducting phase to electronic conducting phase close to 4:1. Meanwhile, the GCFCO phase dominates the effective electronic conductivity.
Original languageEnglish
Pages (from-to)5646-5652
Number of pages7
JournalJournal of the European Ceramic Society
Volume40
Issue number15
Early online date19 Jun 2020
DOIs
Publication statusE-pub ahead of print/First online - 19 Jun 2020

Keywords

  • Ceramic
  • Conductivity
  • Dual phase oxygen transport membrane
  • Microstructure
  • Optimization

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