不同金属外掺杂富勒烯C_(20)M(M=Li,Ti,Fe)的储氢性能

Hydrogen Storage of the Different Kinds of Metal Atoms Coated Fullerene C_(20)M(M=Li,Ti,Fe)

使用密度泛函理论（DFT）中的广义梯度近似（GGA）对经碱金属原子Li、过渡金属原子Ti和Fe修饰的富勒烯C20M（M=Li,Ti,Fe）的储氢性能进行研究.结果表明,C20Li（C20Ti和C20Fe）能够吸附H2的最大数目为6,6和4,与18电子规则相吻合;C20M（M=Li,Ti,Fe）对H2的平均吸附能在0.25-0.80 eV范围内,介于物理吸附和化学吸附之间（0.1-0.8 eV）,因此可以实现常温下对氢的可逆吸附.C20Li主要通过正负电荷形成的偶极矩作用进行储氢,而C20Ti和C20Fe主要通过Dewar-Kubas作用进行储氢.

The hydrogen storage ability of the alkali metal atom Li, transition metal atom Ti and Fe decorated fullerene C20M was studied with the generalized gradient approximation of the density functional theory. Geometry optimization shows that the most stable adsorption position of the metal atom is located above the bridge site of the C--C bond of C20. It is known from the average adsorption energy that the maximum numbers of H2 adsorbed on the C20M（ M = Li, Ti, Fe） are 6, 6 and 4, respectively. They agree well with the 18 electronic rule. The average adsorption energies of C20M-nH2 are in the range from 0. 25 eV to 0. 8 eV, between physical adsorption and chemical adsorption（0.1-0.8 eV）, so it can realize the reversible adsorption of H2. C20Li mainly through the dipole moment formed of positive and negative charge to adsorb H2 molecules, while C20Ti and C2oFe adsorb H2 mainly through Dewar-Kubas role.