Szczegóły publikacji
Opis bibliograficzny
Oxygen storage capability in $Co-$ and $Fe-containing$ perovskite-type oxides / Alicja KLIMKOWICZ, Konrad ŚWIERCZEK, Akito Takasaki, Bogdan Dąbrowski // Solid State Ionics ; ISSN 0167-2738. — 2014 — vol. 257, s. 23–28. — Bibliogr. s. 28, Abstr. — A. Klimkowicz dod. afiliacja: Shibaura Institute of Technology
Autorzy (4)
- AGHKlimkowicz Alicja
- AGHŚwierczek Konrad
- Takasaki Akito
- Dąbrowski Bogdan
Słowa kluczowe
Dane bibliometryczne
| ID BaDAP | 80089 |
|---|---|
| Data dodania do BaDAP | 2014-03-04 |
| Tekst źródłowy | URL |
| DOI | 10.1016/j.ssi.2014.01.018 |
| Rok publikacji | 2014 |
| Typ publikacji | artykuł w czasopiśmie |
| Otwarty dostęp |  |
| Czasopismo/seria | Solid State Ionics |
Abstract
In this paper we report on oxygen storage-related properties of selected Co- and Fe-containing perovskite-type oxides, and analyze their advantages and disadvantages in relation to the Mn-based, A-site ordered BaYMn2O5 + delta system. In particular, the crystal structure of reduced and oxidized Ln(0.5)A'0.5Co0.5Fe0.5O3 - delta (Ln: La, Sm; A': Sr, Ba) and La0.6Sr0.4Co0.8Fe0.2O3 - delta is given, results of in situ XRD observation of the oxidation process of the reduced materials is presented, as well as oxygen storage capacity and kinetics measured on oxidation/reduction cycles in isothermal and non-isothermal conditions are reported. Rietveld refinement of the crystal structure carried out for reduced compounds revealed the presence of brownmillerite-type phase for La0.6Sr0.4Co0.2Fe0.8O2.42. La0.5Sr0.5Co0.5Fe0.5O2.53 and Sm0.5Sr0.5Co0.5Fe0.5O2.53. Upon oxidation these materials transform to perovskite-type phase. On the contrary, La0.5Ba0.5Co0.5Fe0.5O3 - delta and A-site cation ordered Sm0.5Ba0.5Co0.5Fe0.5O3 (- delta) possess the same crystal structure in the reduced and oxidized forms. What's more is that the oxidation process causes a significant decrease of the unit cell volume for each studied compound. Rapid in situ XRD studies (1 min scans), performed every 5 degrees C during oxidation of the materials, allowed to observe ongoing structural changes. TG measurements revealed unusually low onset temperatures of oxidation, with reduced La0.5Sr0.5Co0.5 Fe0.5O3 - delta oxidizing at about 40 degrees C. Isothermal oxidation/reduction cycles measured with changing of the atmosphere between air and 5 vol.% H-2 in Ar, performed in 400-600 degrees C allowed to establish oxygen storage-related properties of the studied materials, and it was found that La0.5Sr0.5Co0.5Fe0.5O3 - delta shows enhanced kinetics of the reduction process, while for La0.6Sr0.8Co0.8Fe0.2O3 - delta the measured reversible oxygen storage capacity can exceed 4.2 wt.%, well above that of the BaYMn2O5 + delta system. While these results are very promising, the main drawback arises from a low stability of the considered Co- and Fe-containing oxides, especially in terms of their long-time performance. (C) 2014 Elsevier B.V. All rights reserved.
