在集群中储存气:量子化学研究研究
Rudy W P Wagemans1, Joop H van Lenthe, Petra E de Jongh
1Department of Inorganic Chemistry and Catalysis, Debye Institute, Utrecht University, P. O. Box 80083, NL-3508TC Utrecht, The Netherlands.
Journal of the American Chemical Society
|November 25, 2005
概括
减少化晶体大小可以显著降低的脱吸温度. 这项研究表明,纳米级化可以在200°C时释放,克服了其用于储存的关键障碍.
科学领域:
- 材料科学 材料科学 材料科学
- 计算化学的计算化学
- 储能 储能 储能 储能 储能 储能
背景情况:
- 化 (MgH2) 是一个有前途的,具有成本效益的存材料,由于其高含量 (7.7 wt%).
- 大量MgH2的高脱吸温度 (≥300°C) 阻碍了其实际应用.
- 文献表明,在无序的材料和薄膜中,可能可以达到较低的脱吸温度.
研究的目的:
- 系统地研究晶粒大小对和化的热力学稳定性的影响.
- 为了确定结晶体大小和溶解温度之间的关系.
- 探索纳米级MgH2在改进存应用中的潜力.
主要方法:
- 最初使用了哈特里-福克和密度函数理论计算.
- 研究了减少集群大小对和化稳定性的影响.
- 详细分析了循序渐进的溶解过程.
主要成果:
- 和化都表现出降低的热力学稳定性,随着集群大小的减少,特别是在20个原子以下.
- 化随着尺寸的减少而比更显著地破坏稳定.
- 对于大约1.3nm以下的晶石大小,观察到溶解能量的大幅下降.
- 0.9nm的MgH2结晶体大小预测了低至200°C的脱吸温度.
结论:
- 降低化的晶粒大小有效降低了其溶解温度.
- 纳米级化显示出克服储存中的热力学限制的潜力.
- 这项工作代表了作为储材料的实际应用的重大进展.
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