A synergistic effect of NH3BH3 and H2 on their pressurization metallization: An Ab initio molecular dynamics study
A synergistic effect of NH3BH3 and H2 on their pressurization metallization: An Ab initio molecular dynamics study
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NH3BH3 和 H2 对加压金属化的协同效应：从头算分子动力学研究
DOI：
10.1016/j.commatsci.2022.111972
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发表时间：
2022-12-17
影响因子：
3.3
通讯作者：
Ji，Guang-Fu
中科院分区：
文献类型：
--
作者：
Huang，Yao-Yao;Ji，Lin-Xiang;Ji，Guang-Fu
氨硼烷（NH3BH3， AB）作为一种典型的富氢化合物，有望成为低压金属化材料中很有前途的氢源。然而，它在压力下的微观电子特性还没有得到充分的了解。在本研究中，我们采用从头算分子动力学方法系统地研究了AB及其配合物与h2的加压过程，揭示了它们的金属化机制。随着压力的增加，AB首先发生部分脱氢，释放出一些h2分子。在450 GPa的金属化压力下，通过新形成的h2和-BHxgroup之间的Hsingle bondH⋯Hsingle bond db相互作用，有效地促进了金属化进程。对于ab单键dh2化合物，AB的电子态首先通过由额外的H2衍生的h单键h⋯h单键db的增强相互作用被激活。反过来，相应h2分子内的h单键h键部分极化。特殊的h2对是通过Hsingle bondH⋯Hsingle bondH相互作用形成的，促进了电子之间的弥散。ABsingle - bondh2系统的整个电子通道通过Hsingle - bonh⋯Hsingle - bondB和Hsingle - bonh⋯Hsingle - bonh的协同相互作用串联在一起，显著加快了加压金属化进程，使金属化压力真正降低到250 GPa。我们的研究首次阐明了AB和H2system的协同金属化机制，这将为氢或富氢材料的低压金属化研究提供很大的启发。
Ammonia borane (NH3BH3, AB), as a typical hydrogen-rich compound, is expected to be a promising hydrogen source for low-pressure metallization materials. However, its microscopic electronic properties subjected to pressure are not sufficiently understood yet. In this study, we systematically investigate the pressurization process of AB and its complex with H2to uncover their metallization mechanism, using ab initio molecular dynamics method. As pressure increase, AB first undergoes partial dehydrogenation to liberate some H2molecules. The metallization progress is effectively promoted via Hsingle bondH⋯Hsingle bondB interaction between new-formed H2and -BHxgroup, with the metallization pressure of 450 GPa. As to ABsingle bondH2compound, the electron states of AB are first activated through the enhanced interaction of Hsingle bondH⋯Hsingle bondB deriving from the additional H2. In turn, the Hsingle bondH bonds within the corresponding H2molecules are partially polarized. The special H2-couples are formed through the Hsingle bondH⋯Hsingle bondH interaction, promoting the electron dispersion with each other. The whole electron channel of ABsingle bondH2system is threaded together by the synergistic interactions of Hsingle bondH⋯Hsingle bondB and Hsingle bondH⋯Hsingle bondH, which significantly accelerate the pressurization metallization progress, resulting in a really lower metallization pressure of 250 GPa. Our study elucidate the synergistic metallization mechanism of AB and H2system for the first time, which would provide a great inspiration for low-pressure metallization studies of hydrogen or hydrogen-rich materials.