TY - JOUR

T1 - Phase composition and proton uptake of acceptor-doped self-generated Ba(Ce,Fe)O3-δ – Ba(Fe,Ce)O3-δ composites

AU - Nader, Christina

AU - Lammer, Judith

AU - Egger, Andreas

AU - Berger, Christian

AU - Sitte, Werner

AU - Grogger, Werner

AU - Merkle, Rotraut

AU - Maier, Joachim

AU - Bucher, Edith

N1 - Publisher Copyright: © 2024 The Authors

PY - 2024/3

Y1 - 2024/3

N2 - Self-generated Ba(Ce,Fe,In)O 3-δ composites were prepared by one-pot sol-gel synthesis. They consist of Ce-rich and Fe-rich phases, and are intended to supply the required protonic and electronic transport for air electrode materials in protonic ceramic fuel and electrolysis cells (PCFC, PCEC). Crystal structure, lattice parameters, and the relative phase amounts of the composites were obtained from X-ray diffraction. The local chemical composition and distribution of cations within the individual phases were characterized by scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy. Annealing experiments indicate that the miscibility gap of the BaCe 0.8-xFe xIn 0.2O 3-δ system ranges from [Ce]/([Ce] + [Fe]) ratios of ~ 0.2 to ~ 0.9. The In 3+ acceptor shows a tendency to accumulate in the Fe-rich phase, with the ratio In(Ce-rich phase)/In(Fe-rich phase) being in the range of 0.3–0.7. The proton uptake capacity of the materials, which was analyzed by thermogravimetry, increases with an increasing amount of In and decreasing amount of Fe in the precursor. Proton concentrations are in the range of 1–4 mol% at 400 °C. Further measurements on BaCe 0.4Fe 0.4Acc 0.2O 3-δ (Acc = Y, Yb, Gd, Sm, Sc) composites show that proton uptake is generally increased compared to the undoped system BaCe 0.5Fe 0.5O 3-δ. However, variations in the acceptor ion can tune the proton uptake only to a limited extent.

AB - Self-generated Ba(Ce,Fe,In)O 3-δ composites were prepared by one-pot sol-gel synthesis. They consist of Ce-rich and Fe-rich phases, and are intended to supply the required protonic and electronic transport for air electrode materials in protonic ceramic fuel and electrolysis cells (PCFC, PCEC). Crystal structure, lattice parameters, and the relative phase amounts of the composites were obtained from X-ray diffraction. The local chemical composition and distribution of cations within the individual phases were characterized by scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy. Annealing experiments indicate that the miscibility gap of the BaCe 0.8-xFe xIn 0.2O 3-δ system ranges from [Ce]/([Ce] + [Fe]) ratios of ~ 0.2 to ~ 0.9. The In 3+ acceptor shows a tendency to accumulate in the Fe-rich phase, with the ratio In(Ce-rich phase)/In(Fe-rich phase) being in the range of 0.3–0.7. The proton uptake capacity of the materials, which was analyzed by thermogravimetry, increases with an increasing amount of In and decreasing amount of Fe in the precursor. Proton concentrations are in the range of 1–4 mol% at 400 °C. Further measurements on BaCe 0.4Fe 0.4Acc 0.2O 3-δ (Acc = Y, Yb, Gd, Sm, Sc) composites show that proton uptake is generally increased compared to the undoped system BaCe 0.5Fe 0.5O 3-δ. However, variations in the acceptor ion can tune the proton uptake only to a limited extent.

KW - Barium indium cerate

KW - Barium indium ferrate

KW - Crystal structure

KW - Miscibility gap

KW - Proton uptake capacity

KW - Self-generated composite

UR - http://www.scopus.com/inward/record.url?scp=85183452088&partnerID=8YFLogxK

U2 - 10.1016/j.ssi.2024.116474

DO - 10.1016/j.ssi.2024.116474

M3 - Article

VL - 406.2024

JO - Solid State Ionics

JF - Solid State Ionics

SN - 0167-2738

IS - March

M1 - 116474

ER -