基于Pr(2) NiO(4) 的混合导体的晶体结构,扩散路径和氧气透性 (Pr(0.9) La ((0.1)) ((2) ((Ni ((0.74) Cu ((0.21) Ga ((0.05)) O ((4+delta)
Masatomo Yashima1, Nuansaeng Sirikanda, Tatsumi Ishihara
1Department of Materials Science and Engineering, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-Ku, Yokohama, Kanagawa 226-8502, Japan. yashima@materia.titech.ac.jp
Journal of the American Chemical Society
|February 4, 2010
概括
这项研究表明,化氧化 (Pr0.9La0.1) 2 (Ni0.74Cu0.21Ga0.05) O4+δ) 由于有效的离子扩散通路,具有出色的氧气透性. 它的低激活能量表明在氧气分离应用中具有高性能潜力.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 氧化物离子导体 氧化物离子导体
背景情况:
- 氧化物和氧化物是氧气分离的有希望的混合导体.
- 了解它们的晶体结构和离子扩散对于优化性能至关重要.
研究的目的:
- 为了研究一种特定的化氧化物 (Pr0.9La0.1) 2 (Ni0.74Cu0.21Ga0.05) O4+δ (PLNCG) 的现场晶体结构,氧气扩散,透率和导电性.
- 阐明氧气扩散机制及其与材料特性之间的关系.
主要方法:
- 在空气中广泛的温度范围 (271015.6°C) 中对PLNCG特性进行实地调查.
- 利用中子和同步子衍射,瑞特维尔德精细化,最大率方法 (MEM) 和理论计算.
- 分析了电子密度图和最高占成的分子轨道 (HOMO),以了解结合和导电.
主要成果:
- PLNCG保持一个四边形的K(2) NiF(4) 类型结构,具有2D共价Ni-O网络.
- 实现了高批量氧气透率 (1000 °C时137 μmol cm−2 min−1) 与低激活能 (550 °C时51 kJ mol−1).
- 确定了间歇性O3和异型的顶端O2位点,作为散装氧化物离子扩散的关键,扩散途径在更高的温度下得到加强.
结论:
- 被研究的化氧化表明,由特定的批量扩散通路驱动的高效氧气透.
- 氧气透的低激活能量表明在氧气分离技术中的应用有很大的潜力,特别是高质量的单晶或薄膜.
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