Tsere Melkizedeck H, Pogrebnaya Tatiana P, Pogrebnoi Alexander M
Department of Natural Sciences, Mbeya University of Science and Technology (MUST), P.O.Box 131, Mbeya, Tanzania.
Department of Materials, Energy Science and Engineering, The Nelson Mandela African Institution of Science and Technology (NM-AIST), P.O.Box 447, Arusha, Tanzania.
J Mol Model. 2020 Dec 17;27(1):2. doi: 10.1007/s00894-020-04601-3.
Metal hydrides are feasible for energy storage applications as they are able to decompose with hydrogen gas release. In this work, gaseous complex sodium hydrides, NaMH and NaMH (M = B or Al), have been investigated using DFT/B3P86 and MP2 methods with 6-311++G(d,p) basis set; the optimized geometry, vibrational spectra and thermodynamic (TD) properties have been determined. Based on TD approach, a stability of the hydrides to different dissociation channels is analysed; the enthalpies of formation ∆H°(0) of gaseous species have been obtained: - 1 ± 17 kJ mol (NaBH), 91 ± 14 kJ mol (NaAlH), - 13 ± 16 kJ mol (NaBH), and 71 ± 16 kJ mol (NaAlH). The complex hydrides are confirmed to produce gaseous products with hydrogen gas release at elevated temperature, whereas heterophase reactions, with NaH and B/Al products in condensed state, are predicted to occur spontaneously at lower temperature. Graphical abstract.
金属氢化物对于能量存储应用是可行的，因为它们能够分解并释放氢气。在这项工作中，使用具有6-311++G(d,p)基组的DFT/B3P86和MP2方法研究了气态复合氢化钠NaMH和NaMH（M = B或Al）；确定了优化的几何结构、振动光谱和热力学（TD）性质。基于TD方法，分析了氢化物对不同解离通道的稳定性；获得了气态物种的生成焓∆H°(0)：-1±17 kJ mol（NaBH）、91±14 kJ mol（NaAlH）、-13±16 kJ mol（NaBH）和71±16 kJ mol（NaAlH）。证实复合氢化物在高温下会产生气态产物并释放氢气，而预测在较低温度下会自发发生与NaH和凝聚态B/Al产物的异相反应。图形摘要。
