ISSN:
1862-0760
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Physik
Notizen:
Abstract Mixed conducting oxide anodes are being considered for the direct utilisation of natural gas in high temperature fuel cells. This work refers to the electrochemical characterization of the pyrochlore Gd2Ti0.6Mo1.2Sc0.2O7-δ (GTMS) as anode in a solid oxide fuel cell running in low humidity hydrogen or methane. The electro-oxidation reaction was investigated using impedance spectroscopy, potentiostatic measurements and cyclic voltammetry. Kinetic data were obtained for different fuels in the temperature range 845–932 °C. In a methane-fuelled cell, steam reforming appears to be the rate-limiting step. The overall polarisation resistance of the anode under open circuit conditions at 932 °C was 6.86 Ω·cm2 in 97% H2/3% H2O, and 43 Ω·cm2 in 97% CH4/3% H2O. For a 97% fuel-3% H2O/GTMS//YSZ-Al2O3//Pt/air cell, the maximum power output at 932 °C was 9.5 mW/cm2 and 1.8 mW/cm2 in hydrogen and methane, respectively. First investigations on this type of electrode material show unidentified peaks on XRD spectra after electrochemical test, which indicate GTMS instability under experimental conditions.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF02374149
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