Oxygen tracer diffusion and surface exchange kinetics in La0.6Sr0.4CoO3-δ

被引：121

作者：

Berenov, A. V. ^{[1
]}

Atkinson, A. ^{[1
]}

Kilner, J. A. ^{[1
]}

Bucher, E. ^{[2
]}

Sitte, W. ^{[2
]}

机构：

[1] Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2AZ, England

[2] Univ Min & Met Leoben, Chair Phys Chem, A-8700 Leoben, Austria

来源：

SOLID STATE IONICS | 2010年 / 181卷 / 17-18期

基金：

英国工程与自然科学研究理事会;

关键词：

Lanthanum cobaltites; Secondary-Ion Mass Spectroscopy; Oxygen tracer diffusion; Oxygen tracer surface exchange; Solid Oxide Fuel Cells; Cathodes; PEROVSKITE-TYPE OXIDES; CONDUCTIVITY RELAXATION; SOFC-CATHODE; TRANSPORT; NONSTOICHIOMETRY; STRONTIUM; CRYSTAL; LA1-XSRXCOO3; COEFFICIENT; ELECTRODES;

D O I：

10.1016/j.ssi.2010.04.031

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The oxygen tracer diffusion coefficient, D*, and the oxygen tracer surface exchange coefficient, k*, were measured in La0.6Sr0.4CoO3-delta over the temperature range of 406-680 degrees C and the oxygen partial pressure range 0.044-1.019 bar. Distortions of the near surface regions of the diffusion profiles were observed in several specimens. O-18 exchange experiments were modeled by the Finite Element method and the origin of the observed distortions was assigned to exchange of oxygen during sample cooling. The estimated error in the determination of D* and k* was found to be less than 20%. The activation energies of D* and k* were 1.84 +/- 0.02 eV and 0.76 +/- 0.13 eV, respectively. D* was found to decrease with oxygen partial pressure following the power law with a power of -0.55 +/- 0.10. The effect of Sr doping on the values of D* in Ln(1-x)Sr(x)CoO(3-delta) (Ln = La, Sm) perovskites is discussed. The data obtained from isotopic exchange measurements at 500-600 degrees C are in good agreement with the kinetic parameters derived from conductivity relaxation experiments on samples from the same batch. (C) 2010 Elsevier B.V. All rights reserved.

引用

页码：819 / 826

页数：8

共 37 条

[1] Electrode kinetics of porous mixed-conducting oxygen electrodes [J].

Adler, SB ;

Lane, JA ;

Steele, BCH .

JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1996, 143 (11) :3554-3564

[2]

Benson S.J., 1997, P 3 INT S IONIC MIXE, P596

[3] Stability of the SOFC cathode material (Ba,Sr)(Co,Fe)O3-δ in CO2-containing atmospheres [J].

Bucher, E. ;

Egger, A. ;

Caraman, G. B. ;

Sitte, W. .

JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 2008, 155 (11) :B1218-B1224

[4]

BUCHER E, 2003, THESIS U LEOBEN AUST

[5] OXYGEN-TRANSPORT IN SELECTED NONSTOICHIOMETRIC PEROVSKITE-STRUCTURE OXIDES [J].

CARTER, S ;

SELCUK, A ;

CHATER, RJ ;

KAJDA, J ;

KILNER, JA ;

STEELE, BCH .

SOLID STATE IONICS, 1992, 53 :597-605

[6] DEVELOPMENT OF A NOVEL SIMS TECHNIQUE FOR OXYGEN SELF-DIFFUSION AND SURFACE EXCHANGE COEFFICIENT MEASUREMENTS IN OXIDES OF HIGH DIFFUSIVITY [J].

CHATER, RJ ;

CARTER, S ;

KILNER, JA ;

STEELE, BCH .

SOLID STATE IONICS, 1992, 53 (pt 2) :859-867

[7] OXYGEN-ION MIGRATION IN PEROVSKITE-TYPE OXIDES [J].

CHERRY, M ;

ISLAM, MS ;

CATLOW, CRA .

JOURNAL OF SOLID STATE CHEMISTRY, 1995, 118 (01) :125-132

[8] Rational design of novel cathode materials in solid oxide fuel cells using first-principles simulations [J].

Choi, YongMan ;

Lin, M. C. ;

Liu, Meilin .

JOURNAL OF POWER SOURCES, 2010, 195 (05) :1441-1445

[9]

CRANK J, 1964, MATH DIFFUSION, P34

[10]

*CRC, 1974, CRC HDB CHEM PHYS, pB250

← 1 2 3 4 →