A ReaxFF Investigation of Hydride Formation in Palladium Nanoclusters via Monte Carlo and Molecular Dynamics Simulations
A ReaxFF Investigation of Hydride Formation in Palladium Nanoclusters via Monte Carlo and Molecular Dynamics Simulations
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DOI：
10.1021/jp411015a
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发表时间：
2014-02
影响因子：
3.7
通讯作者：
T. Senftle;M. Janik;A. Duin
中科院分区：
文献类型：
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作者：
T. Senftle;M. Janik;A. Duin
钯可以很容易地从气相中解离和吸收氢，使其可用于储氢设备、分离膜和加氢催化剂。为了在原子尺度上研究Pd中的氢输运性质，我们从大量的体相和表面性质的量子数据中推导出了Pd/H的Reaxff相互作用势。利用这个势能，我们用最近发展起来的巨正则-蒙特卡罗/分子动力学(GC-MC/MD)方法，在氢压从10-1atm到10-14atm，温度从300K到500K的范围内，推导了Pd大块晶体和纳米团簇的理论吸氢等温线。对平衡团簇结构的分析揭示了表面、亚表面和块体区域在固溶体α相和氢化物β相之间依赖于尺寸的转变过程中所起的作用。此外，还对氢气在气相中的解离吸附进行了分子动力学模拟。
Palladium can readily dissociate and absorb hydrogen from the gas phase, making it applicable in hydrogen storage devices, separation membranes, and hydrogenation catalysts. To investigate hydrogen transport properties in Pd on the atomic scale, we derived a ReaxFF interaction potential for Pd/H from an extensive set of quantum data for both bulk and surface properties. Using this potential, we employed a recently developed hybrid grand canonical-Monte Carlo/molecular dynamics (GC-MC/MD) method to derive theoretical hydrogen absorption isotherms in Pd bulk crystals and nanoclusters for hydrogen pressures ranging from 10–1 atm to 10–14 atm, and at temperatures ranging from 300 to 500 K. Analysis of the equilibrated cluster structures reveals the contributing roles of surface, subsurface, and bulk regions during the size-dependent transition between the solid solution α phase and the hydride β phase. Additionally, MD simulations of the dissociative adsorption of hydrogen from the gas phase were conducted to...