TY  - JOUR
AU  - He, Guanghu
AU  - Lan, Qianqian
AU  - Sohn, Yoo Jung
AU  - Baumann, Stefan
AU  - Dunin-Borkowski, Prof. Rafal
AU  - Meulenberg, Wilhelm A
AU  - Jiang, Heqing
TI  - Temperature-Induced Structural Reorganization of W-doped Ba0.5Sr0.5Co0.8Fe0.2O3-δ Composite Membranes for Air Separation
JO  - Chemistry of materials
VL  - 31
IS  - 18
SN  - 1520-5002
CY  - Washington, DC
PB  - American Chemical Society
M1  - FZJ-2019-04423
SP  - 7487-7492
PY  - 2019
AB  - The practical use of Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) prototypical oxygen-transport membrane for air separation is currently hampered by the decomposition of the cubic perovskite into a variant with hexagonal stacking at intermediate temperatures of ≤850 °C, which impairs the oxygen transport. Here, we report the development of a W-doped BSCF composite that contains Fe-rich single perovskite (SP) and W-rich double perovskite (DP) phases with different crystallographic parameters. In contrast to BSCF, the BSCFW SP/DP composite maintains its cubic structure at 800 °C for 200 h, demonstrating its structural stability at intermediate temperatures. We use X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy to show that the enhanced phase stability of the composite is associated with a temperature-induced SP–DP dynamic interaction, which involves W and Fe interdiffusion between the SP and DP phases, dynamically adjusting the chemical composition and limiting structural distortion and new phase formation. The composite exhibits a stable permeation performance in the oxygen-transport membrane during over 150 h operation at 800 and 700 °C, confirming the potential of intermediate-temperature oxygen-transport membranes for air separation and providing insight for designing thermally stable composite oxides.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000487859200042
DO  - DOI:10.1021/acs.chemmater.9b02213
UR  - https://juser.fz-juelich.de/record/864756
ER  -