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A novel concept for the preparation of multiphase composite ceramics based on demixing of a single ceramic precursor has been developed and used for the synthesis of a dual-phase H2-permeable ceramic membrane. The precursor BaCe0.5Fe0.5O3− δ decomposes on calcination at 1370 °C for 10 h into two thermodynamically stable oxides with perovskite structures: the cerium-rich oxide BaCe0.85Fe0.15O3− δ (BCF8515) and the iron-rich oxide BaCe0.15Fe0.85O3− δ (BCF1585), 50 mol % each. In the resulting dual-phase material, the orthorhombic perovskite BCF8515 acts as the main proton conductor and the cubic perovskite BCF1585 as the main electron conductor. The dual-phase membrane shows an extremely high H2 permeation flux of 0.76 mL min−1 cm−2 at 950 °C with 1.0 mm thickness. This auto-demixing concept should be applicable to the synthesis of other ionic-electronic conducting ceramics. [ABSTRACT FROM AUTHOR]

A novel concept for the preparation of multiphase composite ceramics based on demixing of a single ceramic precursor has been developed and used for the synthesis of a dual-phase H2 -permeable ceramic membrane. The precursor BaCe0.5 Fe0.5 O3-δ decomposes on calcination at 1370 °C for 10 h into two thermodynamically stable oxides with perovskite structures: the cerium-rich oxide BaCe0.85 Fe0.15 O3-δ (BCF8515) and the iron-rich oxide BaCe0.15 Fe0.85 O3-δ (BCF1585), 50 mol % each. In the resulting dual-phase material, the orthorhombic perovskite BCF8515 acts as the main proton conductor and the cubic perovskite BCF1585 as the main electron conductor. The dual-phase membrane shows an extremely high H2 permeation flux of 0.76 mL min(-1)  cm(-2) at 950 °C with 1.0 mm thickness. This auto-demixing concept should be applicable to the synthesis of other ionic-electronic conducting ceramics., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)