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Evaluation of Sulfur Dioxide Poisoning for LSCF Cathodes
Author(s) -
Wang F.,
Yamaji K.,
Cho D.H.,
Shimonosono T.,
Nishi M.,
Kishimoto H.,
Brito M. E.,
Horita T.,
Yokokawa H.
Publication year - 2013
Publication title -
fuel cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.485
H-Index - 69
eISSN - 1615-6854
pISSN - 1615-6846
DOI - 10.1002/fuce.201200172
Subject(s) - adsorption , sulfur , cathode , degradation (telecommunications) , oxide , sulfur dioxide , materials science , inorganic chemistry , scavenging , polarization (electrochemistry) , chemical engineering , chemistry , metallurgy , organic chemistry , telecommunications , computer science , engineering , antioxidant
Abstract Sulfur poisoning behavior of La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3–δ (LSCF6428) cathode was investigated at T = 1073 K (800 °C) under 0.1 ppm of SO 2 ‐air mixture gas; the amount of supplied SO 2 was controlled by changing the flow rate. Two stages of the performance degradation were found: a rapid degradation at the early stage and a subsequent monotonic degradation. The elemental distributions of SrSO 4 showed a strong correlation between the electrochemically active sites and SrSO 4 reaction sites in the vicinity of the LSCF6428/10GDC interfaces. Considerations were made to attribute the first and the second stages of performance degradation to the SO 2 adsorption and the SrSO 4 formation, respectively. The SO 2 adsorption mechanism was discussed in terms of the high concentration of oxide ion vacancies in the electrochemically active region under the cathodic polarization condition.