TY - JOUR
T1 - Catalytic chemical potential shift on the surface of nonstoichiometric oxides under non-equilibrium gas atmosphere
AU - Yashiro, Keiji
AU - Onuma, Shigenori
AU - Sase, Maya
AU - Kaimai, Atsushi
AU - Otake, Takanori
AU - Matsumoto, Hiroshige
AU - Kawada, Tatsuya
AU - Mizusaki, Junichiro
N1 - Funding Information:
This study was partly supported by the Ministry of Education, Culture, Sports, Science and Technology, Grant-in-Aid for Scientific Research, Young Scientists (A), 15686033, 2003. A part of this paper was reproduced from the materials of The Electrochemical Society Proceedings (Ref. [6] ) by permission of The Electrochemical Society, Inc.
PY - 2005/10
Y1 - 2005/10
N2 - Perovskite-type oxide, La0.5Sr0.5CoO 3-δ, has large oxygen nonstoichiometry and high electrical conductivity with a large carrier concentration. The oxygen nonstoichiometry, δ, of dense La0.5Sr0.5CoO3-δ was measured in the stream of NOx-O2-N2 system at 873 to 1073 K by means of a thermogravimetric method. Small amounts of NO 2 caused large changes in oxygen nonstoichiometry. It seems probable that excessive amounts of oxygen can be incorporated into the bulk due to catalytic decomposition of NO2, and as a result, oxygen potential on the surface of the sample seems to be much higher than that of gaseous phase. EMF measurements for dense La0.6Sr0.4CoO 3-δ electrode also revealed that the oxygen potential is affected by NO2. Thus, the gas sensing mechanism of this oxide was found to relate to the change of the bulk property, especially oxygen nonstoichiometry.
AB - Perovskite-type oxide, La0.5Sr0.5CoO 3-δ, has large oxygen nonstoichiometry and high electrical conductivity with a large carrier concentration. The oxygen nonstoichiometry, δ, of dense La0.5Sr0.5CoO3-δ was measured in the stream of NOx-O2-N2 system at 873 to 1073 K by means of a thermogravimetric method. Small amounts of NO 2 caused large changes in oxygen nonstoichiometry. It seems probable that excessive amounts of oxygen can be incorporated into the bulk due to catalytic decomposition of NO2, and as a result, oxygen potential on the surface of the sample seems to be much higher than that of gaseous phase. EMF measurements for dense La0.6Sr0.4CoO 3-δ electrode also revealed that the oxygen potential is affected by NO2. Thus, the gas sensing mechanism of this oxide was found to relate to the change of the bulk property, especially oxygen nonstoichiometry.
KW - Chemical potential shift
KW - Lanthanum cobaltite
KW - NO
KW - Oxygen nonstoichiometry
KW - Surface catalytic activity
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U2 - 10.1016/j.ssi.2005.06.027
DO - 10.1016/j.ssi.2005.06.027
M3 - Conference article
AN - SCOPUS:25444503982
SN - 0167-2738
VL - 176
SP - 2411
EP - 2416
JO - Solid State Ionics
JF - Solid State Ionics
IS - 31-34
T2 - 30th Symposium on Solid State Ionics in Japan
Y2 - 1 December 2004 through 3 December 2004
ER -