Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-10T13:33:58.215Z Has data issue: false hasContentIssue false

Thin film cathodes in SOFC research: How to identify oxygen reduction pathways?

Published online by Cambridge University Press:  27 August 2013

Alexander K. Opitz*
Affiliation:
Vienna University of Technology, Institute of Chemical Technologies and Analytics, Getreidemarkt 9/164-EC, 1060 Vienna, Austria
Markus Kubicek
Affiliation:
Vienna University of Technology, Institute of Chemical Technologies and Analytics, Getreidemarkt 9/164-EC, 1060 Vienna, Austria
Stefanie Huber
Affiliation:
Vienna University of Technology, Institute of Chemical Technologies and Analytics, Getreidemarkt 9/164-EC, 1060 Vienna, Austria
Tobias Huber
Affiliation:
Vienna University of Technology, Institute of Chemical Technologies and Analytics, Getreidemarkt 9/164-EC, 1060 Vienna, Austria
Gerald Holzlechner
Affiliation:
Vienna University of Technology, Institute of Chemical Technologies and Analytics, Getreidemarkt 9/164-EC, 1060 Vienna, Austria
Herbert Hutter
Affiliation:
Vienna University of Technology, Institute of Chemical Technologies and Analytics, Getreidemarkt 9/164-EC, 1060 Vienna, Austria
Jürgen Fleig
Affiliation:
Vienna University of Technology, Institute of Chemical Technologies and Analytics, Getreidemarkt 9/164-EC, 1060 Vienna, Austria
*
a)Address all correspondence to this author. e-mail: alexander.opitz@tuwien.ac.at
Get access

Abstract

The considerable potential of model-type thin film electrodes for the investigation of oxygen exchange pathways is demonstrated for different electrode materials on yttria-stabilized zirconia (YSZ). In particular, a correlation of voltage-driven 18O tracer experiments and electrical ac and dc measurements has proven to be helpful when aiming at mechanistic conclusions. For Pt electrodes, two different parallel reaction pathways can be identified under equilibrium conditions. At lower temperatures, a diffusion limited path through the electrode is dominant, whereas at higher temperatures, an electrode surface path with oxygen incorporation at the three-phase boundary determines the electrochemical activity. In addition, for high cathodic polarization, an electrolyte surface path with electron transfer via YSZ outperforms both other pathways. The oxygen incorporation zones of the bulk path as well as the electrolyte surface path can be visualized by 18O tracer incorporation experiments in combination with time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis. A successful separation of surface and bulk path can also be obtained for La0.8Sr0.2MnO3−δ (LSM) electrodes by means of 18O tracer incorporation at different cathodic overpotentials. Under lower polarization, a surface path with oxygen incorporation at the three-phase boundary is dominant, whereas at higher cathodic overpotential, the bulk path becomes significantly more pronounced. These changes are discussed in terms of polarization-induced changes of the ionic conductivity in the LSM electrode. Measurements on the acceptor-doped perovskite-type materials La0.6Sr0.4CoO3−δ (LSC) and La0.6Sr0.4FeO3−δ (LSF) illustrate the limitations of the tracer incorporation method. In the case of highly active LSC electrodes with low polarization resistances, the tracer distribution is determined by the electrolyte, and thus the active sites of the electrodes can no longer be visualized. The effect of polarization-induced changes of the electrode's electronic conductivity is demonstrated for LSF. Only a region close to the current collector remains electrochemically active owing to limited lateral electron transport.

Type
Invited Feature Paper
Copyright
Copyright © Materials Research Society 2013 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Hamann, C.H., Hamnett, A., and Vielstich, W.: Electrochemistry, 2nd ed. (Wiley-VCH, Weinheim, 2007).Google Scholar
Fleig, J.: Solid oxide fuel cell cathodes: Polarization mechanisms and modeling of the electrochemical performance. Annu. Rev. Mater. Res. 33, 361 (2003).CrossRefGoogle Scholar
Fleig, J.: On the width of the electrochemically active region in mixed conducting solid oxide fuel cell cathodes. J. Power Sources 105(2), 228 (2002).CrossRefGoogle Scholar
Janek, J., Luerßen, B., Mutoro, E., Fischer, H., and Günther, S.: In situ imaging of electrode processes on solid electrolytes by photoelectron microscopy and microspectroscopy - the role of the three-phase boundary. Top. Catal. 44(3), 399 (2007).CrossRefGoogle Scholar
Adler, S.B.: Factors governing oxygen reduction in solid oxide fuel cell cathodes. Chem. Rev. 104(10), 4791 (2004).CrossRefGoogle ScholarPubMed
Beck, G., Fischer, H., Mutoro, E., Srot, V., Petrikowski, K., Tchernychova, E., Wuttig, M., Ruhle, M., Luerßen, B., and Janek, J.: Epitaxial Pt(111) thin film electrodes on YSZ(111) and YSZ(100) - preparation and characterisation. Solid State Ionics 178(5–6), 327 (2007).CrossRefGoogle Scholar
Radhakrishnan, R., Virkar, A.V., and Singhal, S.C.: Estimation of charge-transfer resistivity of Pt cathode on YSZ electrolyte using patterned electrodes. J. Electrochem. Soc. 152(5), A927 (2005).CrossRefGoogle Scholar
Chueh, W.C., Lai, W., and Haile, S.M.: Electrochemical behavior of ceria with selected metal electrodes. Solid State Ionics 179(21–26), 1036 (2008).CrossRefGoogle Scholar
Jamnik, J. and Maier, J.: Treatment of the impedance of mixed conductors equivalent circuit model and explicit approximate solutions. J. Electrochem. Soc. 146(11), 4183 (1999).CrossRefGoogle Scholar
Jamnik, J. and Maier, J.: Generalised equivalent circuits for mass and charge transport: Chemical capacitance and its implications. Phys. Chem. Chem. Phys. 3(9), 1668 (2001).CrossRefGoogle Scholar
Baumann, F.S., Fleig, J., Habermeier, H.U., and Maier, J.: Impedance spectroscopic study on well-defined (La, Sr)(Co, Fe)O3-delta model electrodes. Solid State Ionics 177(11–12), 1071 (2006).CrossRefGoogle Scholar
Wang, L., Merkle, R., and Maier, J.: Surface kinetics and mechanism of oxygen incorporation into Ba1-xSrxCoyFe1-yO3-δ SOFC microelectrodes. J. Electrochem. Soc. 157(12), B1802 (2010).CrossRefGoogle Scholar
Van Herle, J. and McEvoy, A.J.: Oxygen diffusion through silver cathodes for solid oxide fuel cells. J. Phys. Chem. Solids 55(4), 339 (1994).CrossRefGoogle Scholar
Wang, D.Y. and Nowick, A.S.: Cathodic and anodic polarization phenomena at platinum electrodes with doped CeO2 as electrolyte - II. J. Electrochem. Soc. 126(7), 1166 (1979).CrossRefGoogle Scholar
Wang, D.Y. and Nowick, A.S.: Cathodic and anodic polarization phenomena at platinum electrodes with doped CeO2 as electrolyte - I. J. Electrochem. Soc. 126(7), 1155 (1979).CrossRefGoogle Scholar
Kenjo, T. and Shiroichi, N.: Separation of the polarization of a two-electron transfer reaction into those of consecutive one-electron transfer reactions by potential-step chronoamperometry in the oxidation of O2- ion by Pt/YSZ oxygen electrodes. Electrochim. Acta 42(23–24), 3461 (1997).CrossRefGoogle Scholar
Mitterdorfer, A. and Gauckler, L.J.: Reaction kinetics of the Pt, O2(g)c-ZrO2 system: Precursor-mediated adsorption. Solid State Ionics 120(1–4), 211 (1999).CrossRefGoogle Scholar
Robertson, N.L. and Michaels, J.N.: Oxygen-exchange on platinum-electrodes in zirconia cells - location of electrochemical reaction sites. J. Electrochem. Soc. 137(1), 129 (1990).CrossRefGoogle Scholar
Verkerk, M.J., Hammink, M.W.J., and Burggraaf, A.J.: Oxygen transfer on substituted ZrO2, Bi2O3, and CeO2 electrolytes with platinum electrodes. J. Electrochem. Soc. 130(1), 70 (1983).CrossRefGoogle Scholar
Mizusaki, J., Amano, K., Yamauchi, S., and Fueki, K.: Electrode-reaction at Pt, O2(G)/stabilized zirconia interfaces. 2. Electrochemical measurements and analysis. Solid State Ionics 22(4), 323 (1987).CrossRefGoogle Scholar
van der Haar, L.M., den Otter, M.W., Morskate, M., Bouwmeester, H.J.M., and Verweij, H.: Chemical diffusion and oxygen surface transfer of La1-xSrxCoO3-δ studied with electrical conductivity relaxation. J. Electrochem. Soc. 149(3), J41 (2002).CrossRefGoogle Scholar
De Souza, R.A. and Kilner, J.A.: Oxygen transport in La1-xSrxMn1-yCoyO3±δ perovskites: Part I. Oxygen tracer diffusion. Solid State Ionics 106(3–4), 175 (1998).CrossRefGoogle Scholar
De Souza, R.A. and Kilner, J.A.: Oxygen transport in La1-xSrxMn1-yCoyO3±δ perovskites: Part II. Oxygen surface exchange. Solid State Ionics 126(1–2), 153 (1999).CrossRefGoogle Scholar
Sitte, W., Bucher, E., and Preis, W.: Nonstoichiometry and transport properties of strontium-substituted lanthanum cobaltites. Solid State Ionics 154155(0), 517 (2002).CrossRefGoogle Scholar
van Doorn, R.E., Fullarton, I.C., de Souza, R.A., Kilner, J.A., Bouwmeester, H.J.M., and Burggraaf, A.J.: Surface oxygen exchange of La0.3Sr0.7CoO3-δ. Solid State Ionics 96(1–2), 1 (1997).CrossRefGoogle Scholar
Brichzin, V., Fleig, J., Habermeier, H-U., Cristiani, G., and Maier, J.: The geometry dependence of the polarization resistance of Sr-doped LaMnO3 microelectrodes on yttria-stabilized zirconia. Solid State Ionics 152153, 499 (2002).CrossRefGoogle Scholar
la O’, G.J., Yildiz, B., McEuen, S., and Shao-Horn, Y.: Probing oxygen reduction reaction kinetics of Sr-doped LaMnO3 supported on Y2O3-Stabilized ZrO2: EIS of dense, thin-film microelectrodes. J. Electrochem. Soc. 154(4), B427 (2007).CrossRefGoogle Scholar
Yan, L. and Salvador, P.A.: Substrate and thickness effects on the oxygen surface exchange of La0.7Sr0.3MnO3 thin films. ACS Appl. Mater. Interfaces 4(5), 2541 (2012).CrossRefGoogle Scholar
la O’, G.J., Savinell, R.F., and Shao-Horn, Y.: Activity enhancement of dense strontium-doped lanthanum manganite thin films under cathodic polarization: A combined AES and XPS study. J. Electrochem. Soc. 156(6), B771 (2009).CrossRefGoogle Scholar
Bieberle, A., Meier, L.P., and Gauckler, L.J.: The electrochemistry of Ni pattern anodes used as solid oxide fuel cell model electrodes. J. Electrochem. Soc. 148(6), A646 (2001).CrossRefGoogle Scholar
Fleig, J.: Microelectrodes in solid state ionics. Solid State Ionics. 161(3–4), 279 (2003).CrossRefGoogle Scholar
Hertz, J., Rothschild, A., and Tuller, H.: Highly enhanced electrochemical performance of silicon-free platinum/yttria stabilized zirconia interfaces. J. Electroceram. 22(4), 428 (2009).CrossRefGoogle Scholar
Jung, W. and Tuller, H.L.: Investigation of cathode behavior of model thin-film SrTi1-xFexO3−δ (x = 0.35 and 0.5) mixed ionic-electronic conducting electrodes. J. Electrochem. Soc. 155(11), B1194 (2008).CrossRefGoogle Scholar
Mutoro, E., Luerßen, B., Günther, S., and Janek, J.: The electrode model system Pt(O2)YSZ: Influence of impurities and electrode morphology on cyclic voltammograms. Solid State Ionics 180(17–19), 1019 (2009).CrossRefGoogle Scholar
Mutoro, E., Luerßen, B., Günther, S., and Janek, J.: Structural, morphological and kinetic properties of model type thin film platinum electrodes on YSZ. Solid State Ionics 179(21–26), 1214 (2008).CrossRefGoogle Scholar
Opitz, A.K. and Fleig, J.: Investigation of O2 reduction on Pt/YSZ by means of thin film microelectrodes: The geometry dependence of the electrode impedance. Solid State Ionics 181(15–16), 684 (2010).CrossRefGoogle Scholar
Pöpke, H., Mutoro, E., Luerßen, B., and Janek, J.: Oxygen reduction and oxidation at epitaxial model-type Pt(O2)/YSZ electrodes – on the role of PtOx formation on activation, passivation, and charge transfer. Catal. Today 202, 12 (2012).CrossRefGoogle Scholar
Pöpke, H., Mutoro, E., Luerßen, B., and Janek, J.: Oxidation of platinum in the epitaxial model system Pt(111)/YSZ(111): Quantitative analysis of an electrochemically driven PtOx formation. J. Phys. Chem. C 116(2), 1912 (2011).CrossRefGoogle Scholar
Fleig, J., Baumann, F.S., Brichzin, V., Kim, H-R., Jamnik, J., Cristiani, G., Habermeier, H-U., and Maier, J.: Thin film microelectrodes in SOFC electrode research. Fuel Cells 6(3–4), 284 (2006).CrossRefGoogle Scholar
Horita, T., Yamaji, K., Sakai, N., Xiong, Y., Kato, T., Yokokawa, H., and Kawada, T.: Imaging of oxygen transport at SOFC cathode/electrolyte interfaces by a novel technique. J. Power Sources 106(1–2), 224 (2002).CrossRefGoogle Scholar
Horita, T., Yamaji, K., Sakai, N., Yokokawa, H., and Kato, T.: Oxygen transport at the LaMnO3 film/yttria-stabilized zirconia interface under different cathodic overpotentials by secondary ion mass spectrometry. J. Electrochem. Soc. 148(5), J25 (2001).CrossRefGoogle Scholar
Horita, T., Yamaji, K., Sakai, N., Yokokawa, H., Kawada, T., and Kato, T.: Oxygen reduction sites and diffusion paths at La0.9Sr0.1MnO3-x/yttria-stabilized zirconia interface for different cathodic overvoltages by secondary-ion mass spectrometry. Solid State Ionics 127(1–2), 55 (2000).CrossRefGoogle Scholar
Kawada, T., Horita, T., Sakai, N., Yokokawa, H., Dokiya, M., and Mizusaki, J.: A novel technique for imaging electrochemical reaction sites on a solid oxide electrolyte. Solid State Ionics 131(1–2), 199 (2000).CrossRefGoogle Scholar
Kishimoto, H., Sakai, N., Yamaji, K., Horita, T., Brito, M.E., Yokokawa, H., Amezawa, K., and Uchimoto, Y.: Visualization of oxygen transport behavior at metal electrode/oxide electrolyte interface using secondary ion mass spectrometry. Solid State Ionics 179(9–10), 347 (2008).CrossRefGoogle Scholar
Opitz, A.K., Schintlmeister, A., Hutter, H., and Fleig, J.: Visualization of oxygen reduction sites at Pt electrodes on YSZ by means of 18O tracer incorporation: The width of the electrochemically active zone. Phys. Chem. Chem. Phys. 12, 12734 (2010).CrossRefGoogle ScholarPubMed
Fleig, J., Schintlmeister, A., Opitz, A., and Hutter, H.: The determination of the three-phase boundary width of solid oxide fuel cell cathodes by current-driven 18O tracer incorporation. Scr. Mater. 65, 78 (2011).CrossRefGoogle Scholar
Fleig, J.: Voltage-assisted O-18 tracer incorporation into oxides for obtaining shallow diffusion profiles and for measuring ionic transference numbers: Basic considerations. Phys. Chem. Chem. Phys. 11(17), 3144 (2009).CrossRefGoogle Scholar
Minh, N.Q.: Solid oxide fuel cell technology - features and applications. Solid State Ionics 174(1–4), 271 (2004).CrossRefGoogle Scholar
Wilson, J.R., Duong, A.T., Gameiro, M., Chen, H-Y., Thornton, K., Mumm, D.R., and Barnett, S.A.: Quantitative three-dimensional microstructure of a solid oxide fuel cell cathode. Electrochem. Commun. 11(5), 1052 (2009).CrossRefGoogle Scholar
Søgaard, M., Hendriksen, P.V., Mogensen, M., Poulsen, F.W., and Skou, E.: Oxygen nonstoichiometry and transport properties of strontium substituted lanthanum cobaltite. Solid State Ionics 177(37–38), 3285 (2006).CrossRefGoogle Scholar
Kuhn, M., Hashimoto, S., Sato, K., Yashiro, K., and Mizusaki, J.: Oxygen nonstoichiometry and thermo-chemical stability of La0.6Sr0.4CoO3−δ. J. Solid State Chem. 197(0), 38 (2013).CrossRefGoogle Scholar
Januschewsky, J., Ahrens, M., Opitz, A., Kubel, F., and Fleig, J.: Optimized La0.6Sr0.4CoO3-δ thin-film electrodes with extremely fast oxygen-reduction kinetics. Adv. Funct. Mater. 19, 3151 (2009).CrossRefGoogle Scholar
Hayd, J., Dieterle, L., Guntow, U., Gerthsen, D., and Ivers-Tiffée, E.: Nanoscaled La0.6Sr0.4CoO3−δ as intermediate temperature solid oxide fuel cell cathode: Microstructure and electrochemical performance. J. Power Sources 196(17), 7263 (2011).CrossRefGoogle Scholar
Baumann, F.S., Fleig, J., Cristiani, G., Stuhlhofer, B., Habermeier, H-U., and Maier, J.: Quantitative comparison of mixed conducting SOFC cathode materials by means of thin film model electrodes. J. Electrochem. Soc. 154(9), B931 (2007).CrossRefGoogle Scholar
Kuhn, M., Hashimoto, S., Sato, K., Yashiro, K., and Mizusaki, J.: Oxygen nonstoichiometry, thermo-chemical stability and lattice expansion of La0.6Sr0.4FeO3-δ. Solid State Ionics 195(1), 7 (2011).CrossRefGoogle Scholar
Opitz, A.K., Lutz, A., Kubicek, M., Kubel, F., Hutter, H., and Fleig, J.: Investigation of the oxygen exchange mechanism on Pt/YSZ at intermediate temperatures: Surface path versus bulk path. Electrochim. Acta 56(27), 9727 (2011).CrossRefGoogle ScholarPubMed
Ehn, A., Høgh, J., Graczyk, M., Norrman, K., Montelius, L., Linne, M., and Mogensen, M.: Electrochemical investigation of nickel pattern electrodes in H2/H2O and CO/CO2 atmospheres. J. Electrochem. Soc. 157(11), B1588 (2010).CrossRefGoogle Scholar
Kubicek, M., Limbeck, A., Fromling, T., Hutter, H., and Fleig, J.: Relationship between cation segregation and the electrochemical oxygen reduction kinetics of La0.6Sr0.4CoO3-delta thin film electrodes. J. Electrochem. Soc. 158(6), B727 (2011).CrossRefGoogle Scholar
Holzlechner, G., Kubicek, M., Hutter, H., and Fleig, J.: A novel ToF-SIMS operation mode for improved accuracy and lateral resolution of oxygen isotope measurements on oxides. J. Anal. At. Spectrom. 28, 1080 (2013).CrossRefGoogle Scholar
Kubicek, M., Holzlechner, G., Opitz, A.K., Larisegger, S., Hutter, H., and Fleig, J.: A novel ToF-SIMS operation mode for sub 100 nm lateral resolution: Application and performance. Appl. Surf. Sci. (submitted, 2013).CrossRefGoogle Scholar
De Souza, R.A., Zehnpfenning, J., Martin, M., and Maier, J.: Determining oxygen isotope profiles in oxides with time-of-flight SIMS. Solid State Ionics 176(15–16), 1465 (2005).CrossRefGoogle Scholar
Sakaguchi, I. and Haneda, H.: Oxygen tracer diffusion in single-crystal CaTiO3. J. Solid State Chem. 124(1), 195 (1996).CrossRefGoogle Scholar
Newman, J.: Resistance for flow of current to a disk. J. Electrochem. Soc. 113(5), 501 (1966).CrossRefGoogle Scholar
Opitz, A.K., Horlein, M.P., Huber, T., and Fleig, J.: Current-voltage characteristics of platinum model electrodes on yttria-stabilized zirconia. J. Electrochem. Soc. 159(5), B502 (2012).CrossRefGoogle Scholar
Hoerlein, M.P., Opitz, A.K., and Fleig, J.: On the variability of oxygen exchange kinetics of platinum model electrodes on yttria stabilized zirconia. Solid State Ionics 247248, 56 (2013).CrossRefGoogle Scholar
de Ridder, M., Vervoort, A.G.J., van Welzenis, R.G., and Brongersma, H.H.: The limiting factor for oxygen exchange at the surface of fuel cell electrolytes. Solid State Ionics 156(3–4), 255 (2003).CrossRefGoogle Scholar
de Ridder, M., Welzenis, R.G.v., Gon, A.W.D.v.d., Brongersma, H.H., Wulff, S., Chu, W-F., and Weppner, W.: Subsurface segregation of yttria in yttria stabilized zirconia. J. Appl. Phys. 92(6), 3056 (2002).CrossRefGoogle Scholar
Jensen, K.V., Wallenberg, R., Chorkendorff, I., and Mogensen, M.: Effect of impurities on structural and electrochemical properties of the Ni-YSZ interface. Solid State Ionics 160(1–2), 27 (2003).CrossRefGoogle Scholar
Mogensen, M., Jensen, K.V., Jørgensen, M.J., and Primdahl, S.: Progress in understanding SOFC electrodes. Solid State Ionics 150(1–2), 123 (2002).CrossRefGoogle Scholar
Nielsen, J. and Jacobsen, T.: Three-phase-boundary dynamics at Pt/YSZ microelectrodes. Solid State Ionics 178(13–14), 1001 (2007).CrossRefGoogle Scholar
Mutoro, E., Baumann, N., and Janek, J.: Janus-faced SiO2: Activation and passivation in the electrode system platinum/yttria-stabilized zirconia. J. Phys. Chem. Lett. 1, 2322 (2010).CrossRefGoogle Scholar
Janek, J. and Korte, C.: Electrochemical blackening of yttria-stabilized zirconia - morphological instability of the moving reaction front. Solid State Ionics 116(3–4), 181 (1999).CrossRefGoogle Scholar
Maier, J.: Stationary polarization state: Wagner-Hebb analysis and a simple correction procedure, in Physical Chemistry of Ionic Materials - Ions and Electrons in Solids (John Wiley & Sons, Ltd., Chichester, 2004), pp. 454.CrossRefGoogle Scholar
Park, J.H. and Blumenthal, R.N.: Electronic transport in 8 mole percent Y2O3-ZrO2. J. Electrochem. Soc. 136(10), 2867 (1989).CrossRefGoogle Scholar
Heyne, L. and Beekman, N.M.: Electronic transport in calcia-stabilized zirconia. Proc. Br. Ceram. Soc. 19, 229 (1971).Google Scholar
Schmiedl, R., Demuth, V., Lahnor, P., Godehardt, H., Bodschwinna, Y., Harder, C., Hammer, L., Strunk, H.P., Schulz, M., and Heinz, K.: Oxygen diffusion through thin Pt films on Si(100). Appl. Phys. A 62(3), 223 (1996).CrossRefGoogle Scholar
Stumpf, R., Liu, C-L., and Tracy, C.: Reduced oxygen diffusion through beryllium doped platinum electrodes. Appl. Phys. Lett. 75(10), 1389 (1999).CrossRefGoogle Scholar
Kilner, J., Skinner, S., and Brongersma, H.: The isotope exchange depth profiling (IEDP) technique using SIMS and LEIS. J. Solid State Electrochem. 15(5), 861 (2011).CrossRefGoogle Scholar
Kawada, T., Masuda, K., Suzuki, J., Kaimai, A., Kawamura, K., Nigara, Y., Mizusaki, J., Yugami, H., Arashi, H., Sakai, N., and Yokokawa, H.: Oxygen isotope exchange with a dense La0.6Sr0.4CoO3−δ electrode on a Ce0.9Ca0.1O1.9 electrolyte. Solid State Ionics 121(1–4), 271 (1999).CrossRefGoogle Scholar
Newman, J.: Current distribution on a rotating disk below the limiting current. J. Electrochem. Soc. 113(12), 1235 (1966).CrossRefGoogle Scholar
Patrakeev, M.V., Bahteeva, J.A., Mitberg, E.B., Leonidov, I.A., Kozhevnikov, V.L., and Poeppelmeier, K.R.: Electron/hole and ion transport in La1−xSrxFeO3−δ. J. Solid State Chem. 172(1), 219 (2003).CrossRefGoogle Scholar
van Heuveln, F.H., Bouwmeester, H.J.M., and van Berkel, F.P.F.: Electrode properties of Sr-doped LaMnO3 on yttria-stabilized zirconia: I. Three-phase boundary area. J. Electrochem. Soc. 144(1), 126 (1997).CrossRefGoogle Scholar
Jiang, S.P.: A comparison of O2 reduction reactions on porous (La, Sr)MnO3 and (La, Sr)(Co, Fe)O3 electrodes. Solid State Ionics 146(1–2), 1 (2002).CrossRefGoogle Scholar
Huber, T., Kubicek, M., Opitz, A.K., Holzlechner, G., Navickas, E., Hutter, H., and Fleig, J.: (in preparation).Google Scholar