The Sulphur Poisoning Behaviour of Gadolinia Doped Ceria Model Systems in Reducing Atmospheres

Materials

Riza Iskandar¹  Martin Bram²  Veronika Rojek-Wöckner²  Matthias Gerstl³  Andreas Nenning³  Alexander Karl Opitz³  Herbert Hutter³ 

[1] Central Facility for Electron Microscopy (GFE), RWTH Aachen University, Ahornstraße 55, Aachen 52074, Germany;Christian Doppler Laboratory for Interfaces in Metal-Supported Electrochemical Energy Converters, Getreidemarkt 9/164-EC, Vienna 1060, Austria;Institute of Chemical Technologies and Analytics, TU Wien, Getreidemarkt 9/164-EC, Vienna A-1060, Austria;

关键词: ceria;    sulphur poisoning;    SOFC anode;    electrochemical impedance spectroscopy;    ToF-SIMS;    microelectrodes;    XRD;    XPS;    BET;    TEM;   

DOI  :  10.3390/ma9080649

来源: DOAJ

【 摘 要 】

An array of analytical methods including surface area determination by gas adsorption using the Brunauer, Emmett, Teller (BET) method, combustion analysis, XRD, ToF-SIMS, TEM and impedance spectroscopy has been used to investigate the interaction of gadolinia doped ceria (GDC) with hydrogen sulphide containing reducing atmospheres. It is shown that sulphur is incorporated into the GDC bulk and might lead to phase changes. Additionally, high concentrations of silicon are found on the surface of model composite microelectrodes. Based on these data, a model is proposed to explain the multi-facetted electrochemical degradation behaviour encountered during long term electrochemical measurements. While electrochemical bulk properties of GDC stay largely unaffected, the surface polarisation resistance is dramatically changed, due to silicon segregation and reaction with adsorbed sulphur.

【 授权许可】

Unknown