Oxygen reduction at the surface and the hetero-interface of La-Sr-Co-O-oxides

Atsushi Unemoto, Kazuki Nagao, Toshiya Tairako, Koji Amezawa, Tatsuya Kawada

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)

Abstract

To date, we have reported that oxygen surface exchange is enhanced along the hetero-interface consisting of (La,Sr)2CoO4 and (La,Sr)CoO3. However, there still remain questions on the detailed mechanisms. In this study, we examined how the composition of porous (La,Sr)2CoO4, fabricated on (La,Sr)CoO3 film, affects the enhancement. Layered electrodes consisting of porous (La 1-xSrx)2CoO4±δ (x = 1.0 and 0.8) and La0.6Sr0.4CoO3-δ were prepared and tested by impedance spectrometry. Regardless of the La/Sr ratio in (La,Sr)2CoO4 phase, the area specific conductivity was modified at lower temperatures and in higher oxygen partial pressures while the degree of the enhancement was independent of La/Sr ratio. La 0.6Sr0.4CoO3-δ film electrode degraded. Composition analysis of the film surface suggested that it had precipitates such as Sr- and Co-oxides. On the other hand, when porous (La,Sr) 2CoO4 was fabricated on La0.6Sr 0.4CoO3-δ,* film, surface precipitates disappeared. This suggested that the (La,Sr)2CoO4 phase plays an important role to keep the composition of La0.6Sr 0.4CoO3-δ film to be a perovskite structure possibly by accepting and/or releasing cations near the hetero-interface, resulted in the modification of the electrode performance.

Original languageEnglish
Title of host publicationIonic and Mixed Conducting Ceramics 7
PublisherElectrochemical Society Inc.
Pages59-70
Number of pages12
Edition11
ISBN (Electronic)9781566778374
ISBN (Print)9781607681878
DOIs
Publication statusPublished - 2010

Publication series

NameECS Transactions
Number11
Volume28
ISSN (Print)1938-5862
ISSN (Electronic)1938-6737

ASJC Scopus subject areas

  • Engineering(all)

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