Electrochemical and Raman study of La0.7Sr0.3Co0.8Fe0.2O3 − δ reduction
作者： E. Siebert , A. Boréave , F. Gaillard , T. Pagnier
DOI: 10.1016/J.SSI.2013.05.006
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摘要: Abstract The reduction of La 0.7 Sr 0.3 Co 0.8 Fe 0.2 O 3 − δ (LSCF7382) by heat-treatment in H 2 atmosphere or electrochemical polarization has been followed X-ray diffraction and Raman spectroscopy. transition from perovskite ABO 3 to brownmillerite A B 5 occurs at 250–300 °C 10% is reversible. spectrum shows two bands 560 640 cm − 1 that we attribute CoO 4 tetrahedron stretching. Above 600 °C the sample starts decompose irreversibly into Co, , SrO, LaSrFeO . This confirms cations are more reducible than ones. spectra obtained under cathodic LSCF7382/CGO interface 300 °C PO = 10 − 4 0.1 atm show same as for structure. indicates produces 2 + tetrahedral environment, even low reducing overpotentials. Two steps have observed linear sweep voltammetry open circuit voltage relaxation. In both cases, indicate presence environment. first step thus attributed 4 + within phase second one 3 + associated phase. Thermodynamic calculations published literature support this idea. association n-type mobile species (Co ) with oxygen vacancies confirmed.
sci-hub.se 参考文章(61)
E. Siebert, C. Roux, A. Boréave, F. Gaillard, P. Vernoux, Oxido-reduction properties of La0.7Sr0.3Co0.8Fe0.2O3−δ perovskite oxide catalyst Solid State Ionics. ,vol. 183, pp. 40- 47 ,(2011) , 10.1016/J.SSI.2010.11.012
C. Montella, Discussion of the potential step method for the determination of the diffusion coefficients of guest species in host materials. Part I. Influence of charge transfer kinetics and ohmic potential drop Journal of Electroanalytical Chemistry. ,vol. 518, pp. 61- 83 ,(2002) , 10.1016/S0022-0728(01)00691-X
P. Fabry, M. Kleitz, C. Deportes, Sur l'utilisation d'une electrode ponctuelle dans les cellules à oxyde electrolyte solide: I. Application aux mesures thermodynamiques et à la détermination du nombre de transport electronique de l'electrolyte Journal of Solid State Chemistry. ,vol. 5, pp. 1- 10 ,(1972) , 10.1016/0022-4596(72)90001-1
Frank S. Baumann, Jürgen Fleig, Mitsuharu Konuma, Ulrich Starke, Hanns-Ulrich Habermeier, Joachim Maier, Strong Performance Improvement of La0.6Sr0.4Co0.8Fe0.2O3 − δ SOFC Cathodes by Electrochemical Activation Journal of The Electrochemical Society. ,vol. 152, ,(2005) , 10.1149/1.2034529
S. Bebelis, V. Kournoutis, A. Mai, F. Tietz, Cyclic voltammetry of La0.78Sr0.2FeO3−δ and La0.78Sr0.2Co0.2Fe0.8O3−δ electrodes interfaced to CGO/YSZ Solid State Ionics. ,vol. 179, pp. 1080- 1084 ,(2008) , 10.1016/J.SSI.2008.02.028
L-W Tai, MM Nasrallah, Harlan U Anderson, Don M Sparlin, SR Sehlin, Structure and electrical properties of La1−xSrxCo1−yFeyO3. Part 1. The system La0.8Sr0.2Co1−yFeyO3 Solid State Ionics. ,vol. 76, pp. 259- 271 ,(1995) , 10.1016/0167-2738(94)00244-M
C. Greaves, A. J. Jacobson, B. C. Tofield, B. E. F. Fender, A powder neutron diffraction investigation of the nuclear and magnetic structure of Sr2Fe2O5 Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. ,vol. 31, pp. 641- 646 ,(1975) , 10.1107/S0567740875003536
M. Meyyappan, Catalyzed chemical vapor deposition of one-dimensional nanostructures and their applications Progress in Crystal Growth and Characterization of Materials. ,vol. 55, pp. 1- 21 ,(2009) , 10.1016/J.PCRYSGROW.2009.01.001
Q YIN, Y LIN, Beneficial effect of order–disorder phase transition on oxygen sorption properties of perovskite-type oxides Solid State Ionics. ,vol. 178, pp. 83- 89 ,(2007) , 10.1016/J.SSI.2006.11.013
L.S.M. Traqueia, T. Pagnier, F.M.B. Marques, Structural and electrical characterization of titania-doped YSZ Journal of The European Ceramic Society. ,vol. 17, pp. 1019- 1026 ,(1997) , 10.1016/S0955-2219(96)00172-0