Nicholson Kelly M, Sholl David S
School of Chemical & Biomolecular Engineering, Georgia Institute of Technology , 311 Ferst Drive, Atlanta, Georgia 30332-0100, United States.
Inorg Chem. 2014 Nov 17;53(22):11849-60. doi: 10.1021/ic501992x. Epub 2014 Oct 31.
Metal hydrides with high thermodynamic stability are desirable for high-temperature applications, such as those that require high hydrogen release temperatures or low hydrogen overpressures. First-principles calculations have been used previously to identify complex transition metal hydrides (CTMHs) for high temperature use by screening materials with experimentally known structures. Here, we extend our previous screening of CTMHs with a library of 149 proposed materials based on known prototype structures and charge balancing rules. These proposed materials are typically related to known materials by cation substitution. Our semiautomated, high-throughput screening uses density functional theory (DFT) and grand canonical linear programming (GCLP) methods to compute thermodynamic properties and phase diagrams: 81 of the 149 materials are found to be thermodynamically stable. We identified seven proposed materials that release hydrogen at higher temperatures than the associated binary hydrides and at high temperature, T > 1000 K, for 1 bar H2 overpressure. Our results indicate that there are many novel CTMH compounds that are thermodynamically stable, and the computed thermodynamic data and phase diagrams should be useful for selecting materials and operating parameters for high temperature metal hydride applications.
具有高热力学稳定性的金属氢化物适用于高温应用，例如那些需要高氢释放温度或低氢超压的应用。第一性原理计算先前已被用于通过筛选具有实验已知结构的材料来识别用于高温用途的复杂过渡金属氢化物（CTMHs）。在这里，我们基于已知的原型结构和电荷平衡规则，用一个包含149种提议材料的库扩展了我们先前对CTMHs的筛选。这些提议的材料通常通过阳离子取代与已知材料相关。我们的半自动高通量筛选使用密度泛函理论（DFT）和巨正则线性规划（GCLP）方法来计算热力学性质和相图：发现149种材料中有81种在热力学上是稳定的。我们确定了七种提议的材料，它们在高于相关二元氢化物的温度下释放氢气，并且在1巴氢气超压、高温（T > 1000 K）下也能释放氢气。我们的结果表明，有许多新型的CTMH化合物在热力学上是稳定的，并且计算出的热力学数据和相图应该有助于为高温金属氢化物应用选择材料和操作参数。
