TY - JOUR
T1 - The in situ generated emerging phase inside dual phase oxygen transport membranes
AU - Ran, Ke
AU - Zeng, Fanlin
AU - Fischer, Liudmila
AU - Baumann, Stefan
AU - Meulenberg, Wilhelm A.
AU - Neuhaus, Kerstin
AU - Mayer, Joachim
N1 - Funding Information:
This work has been supported by the Deutsche Forschungsgemeinschaft (Project number 387282673 ). KR acknowledges support by the Bundesministerium für Bildung und Forschung (NEUROTEC).
Publisher Copyright:
© 2022 Acta Materialia Inc.
PY - 2022/8/1
Y1 - 2022/8/1
N2 - The in situ generated emerging phase inside the dual-phase oxygen transport membranes (DP-OTMs) plays a crucial role in boosting the overall performance of DP-OTMs. However, its detailed structure and properties are still not fully understood. Utilizing advanced transmission electron microscopy (TEM) techniques, the emerging phase GdxCe1-xFeyCo1-yO3-δ (GCFCO) inside the CexGd1-xO2-δ-FeCo2O4 (CGO-FC2O) OTMs was successfully characterized at the atomic scale. The newly formed GCFCO is primarily surrounded by the CGO, and contributes to a significant reduction of non-solute segregation at the CGO grain boundaries. Electronic characteristics of the GCFCO shows a sensitive dependence on its chemical composition, including the valence state of Ce and Fe as well as the oxygen vacancies. Additional CGO-GCFCO interfaces were introduced, where almost intact crystal structures were observed with slight Gd and Co segregation ∼1 nm at the edges. Approaching the interface, on the CGO side, only a minimum drop of the Ce valence was determined. On the GCFCO side, mixed Ce3+ and Ce4+ are partially occupying the Gd sites, while Fe and Co valence stay constant until the edge. Our study provides novel insight into the phase information within CGO-FC2O composites, which paves the path towards superior performance of various DP-OTMs.
AB - The in situ generated emerging phase inside the dual-phase oxygen transport membranes (DP-OTMs) plays a crucial role in boosting the overall performance of DP-OTMs. However, its detailed structure and properties are still not fully understood. Utilizing advanced transmission electron microscopy (TEM) techniques, the emerging phase GdxCe1-xFeyCo1-yO3-δ (GCFCO) inside the CexGd1-xO2-δ-FeCo2O4 (CGO-FC2O) OTMs was successfully characterized at the atomic scale. The newly formed GCFCO is primarily surrounded by the CGO, and contributes to a significant reduction of non-solute segregation at the CGO grain boundaries. Electronic characteristics of the GCFCO shows a sensitive dependence on its chemical composition, including the valence state of Ce and Fe as well as the oxygen vacancies. Additional CGO-GCFCO interfaces were introduced, where almost intact crystal structures were observed with slight Gd and Co segregation ∼1 nm at the edges. Approaching the interface, on the CGO side, only a minimum drop of the Ce valence was determined. On the GCFCO side, mixed Ce3+ and Ce4+ are partially occupying the Gd sites, while Fe and Co valence stay constant until the edge. Our study provides novel insight into the phase information within CGO-FC2O composites, which paves the path towards superior performance of various DP-OTMs.
KW - EDXS
KW - EELS
KW - Emerging phase
KW - Interface segregation
KW - Oxygen transport membrane
KW - STEM-HAADF
KW - Valence states
KW - n/a OA procedure
UR - http://www.scopus.com/inward/record.url?scp=85130539180&partnerID=8YFLogxK
U2 - 10.1016/j.actamat.2022.118034
DO - 10.1016/j.actamat.2022.118034
M3 - Article
AN - SCOPUS:85130539180
SN - 1359-6454
VL - 234
JO - Acta materialia
JF - Acta materialia
M1 - 118034
ER -