High temperature phase transition in SOFC anodes based on Sr{sub 2}MgMoO{sub 6-{delta}}

Journal Article · Fri May 15 00:00:00 EDT 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.01.018· OSTI ID:21370373

Marrero-Lopez, D ^[1]; Pena-Martinez, J; Ruiz-Morales, J C ^[1]; Martin-Sedeno, M C ^[2]; Nunez, P ^[1]

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1. Departamento de Quimica Inorganica, Universidad de La Laguna, 38200-La Laguna, Tenerife (Spain)
2. Departamento de Quimica Inorganica, Universidad Malaga, 29071-Malaga (Spain)

The double perovskite Sr{sub 2}MgMoO{sub 6-{delta}} has been recently reported as an efficient anode material for solid oxide fuel cells (SOFCs). In the present work, this material have been investigated by high temperature X-ray diffraction (XRD), differential scanning calorimetry (DSC) and impedance spectroscopy to further characterise its properties as SOFC anode. DSC and XRD measurements indicate that Sr{sub 2}MgMoO{sub 6-{delta}} exhibits a reversible phase transition around 275 deg. C from triclinic (I1-bar) with an octahedral tilting distortion to cubic (Fm3-barm) without octahedral distortion. This phase transition is continuous with increasing temperature without any sudden cell volume change during the phase transformation. The main effect of the phase transformation is observed in the electrical conductivity with a change in the activation energy at low temperature. La{sup 3+} and Fe-substituted Sr{sub 2}MgMoO{sub 6-{delta}} phases were also investigated, however these materials are unstable under oxidising conditions due to phase segregations above 600 deg. C. - Graphical abstract: The double perovskite Sr{sub 2}MgMoO{sub 6}, recently proposed as an efficient SOFC anode for direct hydrocarbon oxidation, exhibits a reversible structural phase transition from triclinic to cubic at 275 deg. C.

• OSTI ID: 21370373
• Journal Information: Journal of Solid State Chemistry, Vol. 182, Issue 5; Other Information: DOI: 10.1016/j.jssc.2009.01.018; PII: S0022-4596(09)00025-5; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACTIVATION ENERGY
ANODES
CALORIMETRY
ELECTRIC CONDUCTIVITY
HYDROCARBONS
IMPEDANCE
LANTHANUM IONS
MAGNESIUM COMPOUNDS
MOLYBDATES
OXIDATION
PEROVSKITE
PHASE TRANSFORMATIONS
SEGREGATION
SOLID OXIDE FUEL CELLS
SPECTROSCOPY
STRONTIUM COMPOUNDS
TEMPERATURE RANGE 0400-1000 K
X-RAY DIFFRACTION
ALKALINE EARTH METAL COMPOUNDS
CHARGED PARTICLES
CHEMICAL REACTIONS
COHERENT SCATTERING
DIFFRACTION
DIRECT ENERGY CONVERTERS
ELECTRICAL PROPERTIES
ELECTROCHEMICAL CELLS
ELECTRODES
ENERGY
FUEL CELLS
HIGH-TEMPERATURE FUEL CELLS
IONS
MINERALS
MOLYBDENUM COMPOUNDS
ORGANIC COMPOUNDS
OXIDE MINERALS
OXYGEN COMPOUNDS
PEROVSKITES
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
SCATTERING
SOLID ELECTROLYTE FUEL CELLS
TEMPERATURE RANGE
TRANSITION ELEMENT COMPOUNDS