论文标题
Ni掺杂的小毫克簇中可逆氢存储的合金比率与簇大小：分散校正DFT研究
Alloying Ratio Versus Cluster Size for Reversible Hydrogen Storage in Ni Doped Small Mg Clusters: Dispersion Corrected DFT Study
论文作者
论文摘要
分散校正的密度功能理论（$ω$ B97X-D DFT）方法用于研究$ ni_nmg_m $ $ $ $ $ $ $ $ $ $（1 \ geq n \ geq 3,1 \ geq 3,1 \ geq m \ geq9）$ clusters $ clusters $ clusters $ ni_nmg_m $ $ $ $ $ $ $（1 \ geq n \ geq n \ geq n \ geq nmg_m $ $ clusters $ clusters $ clusters $ clusters $ clusters）。所有这些集群都可以有效地吸附多个$ h_2 $在物理吸附和化学吸附之间的首选结合能（BE）范围内，即$ 0.1 ev \ geq be \ geq0.8 $ ev。 $ h_2 $在$ ni_kmg_k $（ni：mg = 1：1），$ ni_kmg_ {2k} $（ni：mg = 1：2）和$ ni_kmg_ {3k} $（ni：ni：ni：mg = 1：3）（k = 1-3）clusing clyie clairing ni claby ni claby ni ni_kmg_k $（ni：mg = 1：1），$ ni_kmg_ {2k} 尺寸。在每个Ni：mg比率中，较重的簇中吸附的$ h_2 $的数量（k = 2，3）成为最轻的配置中的积分倍数（k = 1）。结果，无论簇大小如何，分子氢的重量密度保持固定在每个Ni：mg比率上。相应的值为$ 17.94 $ $ $ wt \％$ $（1：1）$，$ 14.46 $ $ $ $ wt \％$ $（1：2）$（1：2）$和$ 13.28 $ $ $ wt \％$ $ $（1：3）$（1：3）$（1：3）$明显高于$ 6.5 $ $ $ $ $ 6.5 $ $ $ $ $ $ $ $ $的$ 6.5 $ $ $ $。分子动力学模拟进一步表明，所有簇的室温几乎所有$ H_2 $分子都是可能的。
Dispersion corrected density functional theory ($ω$B97X-D DFT) method is used to study the molecular hydrogen adsorption in $Ni_nMg_m$ $(1\geq n\geq 3,1\geq m\geq9)$ clusters. All these clusters can effectively adsorb multiple $H_2$ in the preferred binding energy (BE) range between physisorption and chemisorption, i.e., $0.1 eV\geq BE \geq0.8 $eV. $H_2$ adsorption on $Ni_kMg_k$ (Ni:Mg=1:1), $Ni_kMg_{2k}$ (Ni:Mg=1:2) and $Ni_kMg_{3k}$ (Ni:Mg=1:3) (k=1-3) clusters shows fascinating behaviours in terms of Ni:Mg alloying ratio and cluster size. In each Ni:Mg ratio, the number of adsorbed $H_2$ in the heavier clusters (k=2, 3) becomes integral multiples of that in the lightest configuration (k=1). As a consequence, the gravimetric density of molecular hydrogen remains fixed at each Ni:Mg ratio irrespective of the cluster size. The corresponding values are $17.94$ $wt\%$ $(1:1)$, $14.46$ $wt\%$ $(1:2)$ and $13.28$ $wt\%$ $(1:3)$, which are significantly higher than the ultimate target of $6.5$ $wt\%$ set by DOE, US. Molecular dynamics simulations further reveal that room temperature desorption of almost all $H_2$ molecules are possible for all the clusters.
