ISSN:
1551-2916
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Mixed-conducting Sr-Fe-Co oxides have potential applications in dense ceramic membranes for high-purity oxygen separation and/or methane conversion to produce syngas (CO + H2), because of their combined high electronic/ionic conductivity and significant oxygen permeability. SrFeCo0.5Oy has been synthesized by the solid-state reaction method. Conductivities were measured at elevated temperatures in various gas environments and increased as temperature and oxygen partial pressure (pO2) increased in the surrounding environment. Neutron powder diffraction experiments revealed that in a high pO2 environment the SrFeCo0.5Oy material consists of three different phases. The relative concentration of each component phase is dependent on temperature and pO2 in the surrounding environment. In air, Sr2(Fe, Co)3Oy (236-phase) is the majority phase and consists of 〉75 wt% of the total, whereas the perovskite and rocksalt phases account for ∼20 and 〈5 wt%, respectively. However, in a reducing environment, the 236-phase decomposes and converts to perovskite and rocksalt phase at high temperature. In an environment of pO2 〈 10−12.2 atm, the 236-phase is completely converted into perovskite (brownmillerite) and rocksalt phases.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1151-2916.2002.tb00508.x
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