Identification of the reaction mechanism of the Pt,O2/La(Sr)Ga(Mg)O3− electrode system

Бронин, Д. И.; Yaroslavtsev, I. Yu.; Näfe, H.; Aldinger, Fritz

doi:10.1016/j.electacta.2004.01.021

Cited by 10 publications

(13 citation statements)

References 23 publications

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“…35 A comparable adsorption entropy amounting to ≈70% of S 0 was obtained from the analysis of electrochemical oxygen reduction kinetics on Pt/YSZ, a process comprising dissociative oxygen adsorption. 36 Therefore we use ∆S ad 0 ) -200 and -120 J/(mol K) as limiting cases (S 0 (O 2 , 1000 K) ) 245 J/(mol K) 37 ). …”

Section: Resultsmentioning

confidence: 99%

Pathways for Oxygen Incorporation in Mixed Conducting Perovskites: A DFT-Based Mechanistic Analysis for (La, Sr)MnO_3−δ

et al. 2010

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An extensive set of DFT calculations on LaMnO 3 slabs has been generated and used as a basis to identify the most probable reaction mechanism for oxygen incorporation into (La, Sr)MnO 3-δ cathode materials. MnO 2 [001] is found to be the most stable surface termination under fuel cell operation conditions (high temperature, high pO 2 , cubic unit cell). Chemisorption leading to the formation of O 2 -, O 2 2-, and O -atop Mn is exothermic, but due to the negative adsorption entropy and electrostatic repulsion the levels of coverage of molecular oxygen adsorbates are low (in the few percent range). Under typical solid oxide fuel cell conditions, a mechanism in which the encounter of O -with a surface oxygen vacancy at the surface is rate-determining exhibits the fastest rate. The variation of the reaction rate and preferred mechanism(s) with adsorbate and point defect concentrations is discussed.

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Section: Resultsmentioning

confidence: 99%

Pathways for Oxygen Incorporation in Mixed Conducting Perovskites: A DFT-Based Mechanistic Analysis for (La, Sr)MnO_3−δ

et al. 2010

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“…On the other hand, the existence of two parallel mechanisms of the cathodic reduction of oxygen does makes it possible to explain the observed dependences of the cathodic process. The notions that the kinetics of electrode processes in systems with an electrolyte on the basis of lanthanum gallate is limited by parallel processes had already been developed in [14,16].…”

Section: The Discussion the Cathodic Polarizationmentioning

confidence: 99%

“…The publications that are devoted to studying interfacial processes in electrode systems with this electrolyte are not numerous [7][8][9][10][11][12][13][14]. The latter was probably connected with the expectation that the mechanism of electrode processes in systems with a solid oxygenconducting electrolyte (SOCE) on the basis of lanthanum gallate was analogous to the mechanism of electrode processes in systems with electrolytes that have a face-centered cubic lattice (fcc).…”

Section: Introductionmentioning

confidence: 99%

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Effect of the Electrode Potential on the Oxygen Reaction Rate in the Electrode System O2, Au/La0.88Sr0.12Ga0.82Mg0.18O2.85

2005

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The polarization dependences of a porous gold electrode in contact with a solid electrolyte of the composition La 0.88 Sr 0.12 Ga 0.82 Mg 0.18 O 2.85 are studied at 600-800 ° C and oxygen pressures of 2 × 10 -2 -1 atm. It is shown that the rate of cathodic reduction of oxygen out of the gas phase depends on the preliminary treatment of the sample. The activation energy is equal to 110-135 kJ mol -1 at a low polarization. After increasing the polarization, the activation energy for the cathodic reduction of oxygen equals 75-85 kJ mol -1 and depends on the oxygen pressure as a power function with a power index of 1/4. The rate of the anodic evolution of oxygen is dependent neither on the preliminary treatment of the sample nor on the oxygen pressure in the gas phase and the polarization curve has a characteristic segment, which corresponds to a limiting overvoltage.

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“…In the intermediate temperatures range (200-400 • C), the contributions intragrains and intergrains may be observed in their entirety but not those relating to the electrodes. These lasts may be analysed at higher temperatures (>400 • C) [30,39,40].…”

Section: Electrochemical Characterizationmentioning

confidence: 99%

Dense La0.9Sr0.1Ga0.8Mg0.2O2.85 electrolyte for IT-SOFC's: Sintering study and electrochemical characterization

Traina

Henrist

Vertruyen

et al. 2011

Journal of Alloys and Compounds

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Identification of the reaction mechanism of the Pt,O2/La(Sr)Ga(Mg)O3− electrode system

Cited by 10 publications

References 23 publications

Pathways for Oxygen Incorporation in Mixed Conducting Perovskites: A DFT-Based Mechanistic Analysis for (La, Sr)MnO_3−δ

Pathways for Oxygen Incorporation in Mixed Conducting Perovskites: A DFT-Based Mechanistic Analysis for (La, Sr)MnO_3−δ

Effect of the Electrode Potential on the Oxygen Reaction Rate in the Electrode System O2, Au/La0.88Sr0.12Ga0.82Mg0.18O2.85

Dense La0.9Sr0.1Ga0.8Mg0.2O2.85 electrolyte for IT-SOFC's: Sintering study and electrochemical characterization

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Identification of the reaction mechanism of the Pt,O2/La(Sr)Ga(Mg)O3− electrode system

Cited by 10 publications

References 23 publications

Pathways for Oxygen Incorporation in Mixed Conducting Perovskites: A DFT-Based Mechanistic Analysis for (La, Sr)MnO3−δ

Pathways for Oxygen Incorporation in Mixed Conducting Perovskites: A DFT-Based Mechanistic Analysis for (La, Sr)MnO3−δ

Effect of the Electrode Potential on the Oxygen Reaction Rate in the Electrode System O2, Au/La0.88Sr0.12Ga0.82Mg0.18O2.85

Dense La0.9Sr0.1Ga0.8Mg0.2O2.85 electrolyte for IT-SOFC's: Sintering study and electrochemical characterization

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About

Pathways for Oxygen Incorporation in Mixed Conducting Perovskites: A DFT-Based Mechanistic Analysis for (La, Sr)MnO_3−δ

Pathways for Oxygen Incorporation in Mixed Conducting Perovskites: A DFT-Based Mechanistic Analysis for (La, Sr)MnO_3−δ