Oxygen Intake/Release Mechanism of Double-Perovskite Type BaYMn2O5+未 (0 鈮?未 鈮?1)
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- 作者：Teruki Motohashi ; Taku Ueda ; Yuji Masubuchi ; Shinichi Kikkawa
- 刊名：The Journal of Physical Chemistry C
- 出版年：2013
- 出版时间：June 20, 2013
- 年：2013
- 卷：117
- 期：24
- 页码：12560-12566
- 全文大小：451K
- 年卷期：v.117,no.24(June 20, 2013)
- ISSN：1932-7455
文摘
The oxygen intake/release processes of double-perovskite type BaYMn2O5+未 (0 鈮?未 鈮?1) were investigated from the viewpoints of crystal structure and reaction kinetics. The X-ray diffraction study on the partially oxidized/reduced BaYMn2O5+未 products has revealed a clear indication of successive phase changes among three distinct forms with 未 鈮?0, 0.5, and 1: the oxygen intake/release processes could proceed with nucleation followed by a growth of the generated phase. It has also appeared that the oxygen intake reaction is controlled by surface reaction at 348 鈮?T 鈮?403 掳C, while the oxygen release process is surface-reaction-controlled at 425 鈮?T 鈮?550 掳C and nucleation-process-controlled at 600 鈮?T 鈮?750 掳C. The activation energy for the oxygen intake process at 348 鈮?T 鈮?403 掳C is Ea = 0.27 eV and is much smaller than those reported for any other perovskite-type oxides indicative of great affinity to oxygen molecules.