Reversible redox reactions in an epitaxially stabilized SrCoOx oxygen sponge
Reversible redox reactions in an epitaxially stabilized SrCoOx oxygen sponge
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DOI：
10.1038/nmat3736
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发表时间：
2013-11-01
期刊：
影响因子：
41.2
通讯作者：
Lee, Ho Nyung
中科院分区：
文献类型：
--
作者：
Jeen, Hyoungjeen;Choi, Woo Seok;Lee, Ho Nyung
在低温下在固体中进行快速、可逆的氧化还原反应而不发生热机械降解，是提高许多能源材料和设备的整体性能和寿命的一种有前途的策略。然而，阳离子的氧化态和高热力学势垒的鲁棒性阻碍了在低温下实现快速催化和本体扩散。在这里，我们报告了一个显着降低的氧化还原温度的外延稳定的锶钴酸盐（SrCoOx）直接生长的两个不同的结晶相，无论是钙钛矿SrCoO 3-δ或brownmillerite SrCoO2.5。重要的是，这两个相可以在相当短的时间内在显著降低的温度（200-300摄氏度）下可逆地切换（
Fast, reversible redox reactions in solids at low temperatures without thermomechanical degradation are a promising strategy for enhancing the overall performance and lifetime of many energy materials and devices. However, the robust nature of the cation's oxidation state and the high thermodynamic barrier have hindered the realization of fast catalysis and bulk diffusion at low temperatures. Here, we report a significant lowering of the redox temperature by epitaxial stabilization of strontium cobaltites (SrCoOx) grown directly as one of two distinct crystalline phases, either the perovskite SrCoO3-delta or the brownmillerite SrCoO2.5. Importantly, these two phases can be reversibly switched at a remarkably reduced temperature (200-300 degrees C) in a considerably short time (