Reactivity of Gold Clusters in the Regime of Structural Fluxionality
Reactivity of Gold Clusters in the Regime of Structural Fluxionality
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DOI：
10.1021/jp511913t
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发表时间：
2015-05-21
影响因子：
3.7
通讯作者：
Taketsugu, Tetsuya
中科院分区：
文献类型：
--
作者：
Gao, Min;Lyalin, Andrey;Taketsugu, Tetsuya
本文采用全局反应路线图（GRRM）技术，结合非谐向下畸变跟踪（ADDF）和人工力诱导反应（AFIR）方法，系统研究了H-2在中性、带正电荷和带负电荷的金团簇Au-n（q）（n = 2-11; q = 0; +/- 1）上的吸附和解离.一个详尽的搜索H-2的解离途径不仅进行最稳定的簇结构，但也对大量的低能量异构体，允许它们之间的结构转换。本策略可以自动识别的结构依赖的最低过渡态（TS）的H-2解离与系统的过程中的制度，在有限的温度下的金团簇的结构流动性。研究了温度效应、团簇异构化以及金团簇电荷状态对H-2吸附和解离的影响。它表明，最稳定的结构的金簇并不总是高度反应性的，和同分异构体结构的合奏必须考虑到在有限温度下的反应速率的充分描述。所提出的方法可以作为一个有前途的工具，系统的分析和预测的小金属团簇的反应性。
This work present results of a systematic investigation of adsorption and dissociation of H-2 on the neutral, positively, and negatively charged gold clusters Au-n(q) (n = 2-11; q = 0; +/- 1) using the global reaction route mapping (GRRM) technique combined with the anharmonic downward distortion following (ADDF) and the artificial force-induced reaction (AFIR) methods. An exhaustive search for H-2 dissociation pathways is performed not only on the most stable cluster structures but also on the large number of low-energy isomers, allowing structural transformations between them. The present strategy can automatically identify the structure-dependent lowest transition states (TS) for H-2 dissociation with a systematic procedure in the regime of the structural fluxionality of gold clusters at finite temperature. Temperature effects, cluster isomerization, and influence of the charge state of gold clusters on H-2 adsorption and dissociation are studied. It is demonstrated that the most stable structures of the gold clusters are not always highly reactive, and an ensemble of isomeric structures must be taken into account for adequate description of the reaction rates at finite temperatures. The proposed approach can serve as a promising tool for a systematic analysis and prediction of reactivity of small metal clusters.