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Abstract: A series of cobalt-free and low cost BaCe x Fe1−x O3−δ (x =0.15, 0.50, 0.85) materials are successful synthesized and used as the cathode materials for proton-conducting solid oxide fuel cells (SOFCs). The single cell, consisting of a BaZr0.1Ce0.7Y0.2O3−δ (BZCY7)-NiO anode substrate, a BZCY7 anode functional layer, a BZCY7 electrolyte membrane and a BaCe x Fe1−x O3−δ cathode layer, is assembled and tested from 600 to 700°C with humidified hydrogen (∼3% H2O) as the fuel and the static air as the oxidant. Within all the cathode materials above, the cathode BaCe0.5Fe0.5O3−δ shows the highest cell performance which could obtain an open-circuit potential of 0.99V and a maximum power density of 395mWcm−2 at 700°C. The results indicate that the Fe-doped barium cerates can be promising cathodes for proton-conducting SOFCs. [Copyright &y& Elsevier]

Abstract: Stable BaCe0.5Zr0.3Y0.16Zn0.04O3−δ (BCZYZ) thin membrane was successfully prepared by in situ tape casting/co-firing method for proton-conducting solid oxide fuel cells. The starting powders were BaCO3, CeO2, ZrO2, Y2O3, ZnO for electrolyte and BaCO3, CeO2, ZrO2, Y2O3, ZnO, NiO, graphite for anode. The anode/electrolyte bi-layers were prepared by a simple multi-layer tape casting/co-firing method. The phase characterizations and microstructures were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The anode–electrolyte bi-layers were sintered at 1450°C. The electrolytes were extremely dense with pure perovskite phase and the thickness was about 25μm. The anodes were porous and no obvious reaction was found between NiO and BCZYZ. With LaSr3Co1.5Fe1.5O10−δ (LSCF)/BCZYZ as cathode, the open current voltage and maximum power density respectively, reached 1.00V and 247mWcm−2 at 650°C. [Copyright &y& Elsevier]

Abstract: Composite membranes based on Ni and Zr-doped BaCeO3 are promising for hydrogen separation. Such composites show high proton conductivity and adequate chemical stability in H2O and CO2, but may be unstable in H2S. In this work, the hydrogen permeation performance of Ni–BaZr0.1Ce0.7Y0.2O3−δ was measured in an H2S-containing atmosphere at 900°C. The hydrogen permeation flux began to degrade in 60ppm H2S and decreased by about 45% in 300ppm H2S. After hydrogen permeation tests, X-ray diffraction analysis revealed the formation of BaS, doped CeO2, Ni3S2 and Ce2O2S. Analysis of the microstructure and phase composition, and results of thermodynamic calculations suggest that reaction between H2S and doped BaCeO3 caused the performance loss of the Ni–BaZr0.1Ce0.7Y0.2O3−δ . [Copyright &y& Elsevier]

Abstract: In order to develop a simple and cost-effective route to fabricate protonic ceramic membrane fuel cells (PCMFCs) with layered GdBaCo2O5+x (GBCO) cathode, a dense BaZr0.1Ce0.7Y0.2O3−δ (BZCY7) electrolyte was fabricated on a porous anode by gel-casting and suspension spray. The porous NiO–BaZr0.1Ce0.7Y0.2O3−δ (NiO–BZCY7) anode was directly prepared from metal oxide (NiO, BaCO3, ZrO2, CeO2 and Y2O3) by a simple gel-casting process. A suspension of BaZr0.1Ce0.7Y0.2O3−δ powders synthesized by gel-casting was then employed to deposit BaZr0.1Ce0.7Y0.2O3−δ (BZCY7) thin layer by pressurized spray process on NiO–BZCY7 anode. The bi-layer with 10μm dense BZCY7 electrolyte was obtained by co-sintering at 1400°C for 5h. With layered GBCO cathode synthesized by gel-casting on the bi-layer, single cells were assembled and tested with H2 as fuel and the static air as oxidant. An open-circuit potential of 0.98V, a maximum power density of 266mWcm−2, and a low polarization resistance of the electrodes of 0.16Ωcm2 was achieved at 700°C. [Copyright &y& Elsevier]