H2在Li掺杂Al6Si+上吸附的理论研究

本文利用密度泛函理论的B3LYP/6-31G(d, p)和组态相互作用的QCISD/6-31G(d, p)研究了Al6Si+和Al6SiLi+团簇的几何和电子结构及其对H2分子的吸附，两种不同方法计算的H2分子在团簇上的吸附能非常一致。H2分子在Al6Si+团簇上的吸附能仅为-0.018 eV，Al6Si+团簇中掺杂Li原子可以明显增强其对H2分子的吸附。Al6SiLi+团簇吸附一个H2分子的吸附能可以达到-0.157 eV，吸附五个H2分子的平均吸附能为-0.088 eV。态密度和自然键轨道分析表明，电荷从Li原子向Si原子转移，H2分子在带正电的Li离子产生的电场中发生极化，从而在静电相互作用下吸附在Li原子周围。

Theoretical study of adsorption of H2 on Li-doped Al6Si+ cluster

Adsorptions of the H2 molecules on Al6Si+ cluster and the Li-doped Al6Si+ cluster are investigated using density functional theory(DFT) B3LYP/6-31G(d, p) and configuration interaction QCISD/6-31G(d, p). For the Al6Si+ cluster, the adsorption energy of H2 molecule is only -0.018eV. The adsorption of H2 molecules can be markedly strengthened by doping Li atom into Al6Si+ cluster. The average adsorption energy can reach -0.157 eV and -0.088 eV when one and five H2 molecules are adsorbed. The DOS and Molecular orbital composition analysis show that electrons transfer from Li to Si atom, the positively charged Li+ could polarize H2 molecules, H2 molecules are adsorbed around the Li atom by electrostatic interaction.