Currently, solid oxide fuel cell (SOFC) anode materials do not support the use of complex hydrocarbon fuels, high molecular weight with hydrogen sulfide contaminants, which can lead to eventual device failure brought upon by unwanted graphitic and metal sulfide formations. These limitations have spurred the investigation of new mixed ionic and electronic conducting (MIEC) anode materials that can be effective at blocking these detrimental formations. The material of interest in these studies is the double perovskite, Sr2Fe1.5Mo0.5O6-δ(SFMO). High device operating temperatures, ≥600°C, and inaccessible device architectures, present challenges to validate material and chemical processes associated fuel oxidation mechanisms occurring in these devices. The redox chemistry of each metal (Sr, Fe, Mo) of this material was explored using X-ray absorption spectroscopy in conjunction with a unique, custom built reactor assembly to allow for the non-invasive exploration of these materials during device operation at 800°C and in reactive atmospheres. This work was completed at the 10-ID Beamline located at the Advance Photon Source at Argonne National Laboratory. The data revealed that each metal in this electrode material exhibited some degree of partial reduction as evident in the observation of edge energies shifts in the near edge X-ray absorption fine structure data. Upon further investigation, of the extended X-ray absorption fine structure data, the SFMO material was able to maintain its crystal structure integrity amidst the changes in metal oxidation states.

High temperature X-ray absorption spectroscopic investigation of Sr2Fe1.5Mo0.5O6-δ solid oxide fuel cell electrodes

249th National Meeting (2015)

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