标题： 钪修饰的C$_{24}$富勒烯作为高容量可逆氢存储材料：密度泛函理论模拟的见解 显示英文标题

标题： Scandium decorated C$_{24}$ fullerene as high capacity reversible hydrogen storage material: Insights from density functional theory simulations

摘要： 使用第一性原理密度泛函理论模拟，我们观察到钪修饰的C$_{24}$球烯可以吸附多达六个氢分子，每个H$_2$的平均吸附能为-0.35 eV，平均解吸温度为451 K。钪修饰的C$_{24}$球烯系统的重量百分比氢含量为13.02%，这明显高于美国能源部的要求。 通过态密度、空间电荷密度差图和Bader电荷分析解释了电子结构、轨道相互作用和电荷转移机制。 从钪的3d和4s轨道到C$_{24}$球烯的2p碳轨道的总电荷转移量为1.44e。 氢分子通过Kubas类型的相互作用附着在钪修饰的C$_{24}$球烯上。 扩散能垒计算预测，存在足够的能垒将防止金属-金属团聚。 从头算分子动力学（A.I.M.D.）模拟证实了在最高解吸温度下结构的稳定性。 因此，我们认为钪修饰的C$_{24}$球烯系统是一种热力学稳定、有前途的可逆高容量氢储存装置。 显示英文摘要

摘要： Using first-principles density functional theory simulations, we have observed that the scandium decorated C$_{24}$ fullerene can adsorb up to six hydrogen molecules with an average adsorption energy of -0.35 eV per H$_2$ and average desorption temperature of 451 K. The gravimetric wt % of hydrogen for the scandium decorated C$_{24}$ fullerene system is 13.02%, which is sufficiently higher than the Department of Energy, United States demand. Electronic structure, orbital interactions, and charge transfer mechanisms are explained using the density of states, spatial charge density difference plots, and Bader charge analysis. A total amount of 1.44e charge transfer from the 3d and 4s orbitals of scandium to the 2p carbon orbitals of C$_{24}$ fullerene. Hydrogen molecules are attached to scandium decorated C$_{24}$ fullerene by Kubas type of interactions. Diffusion energy barrier calculations predict that the existence of a sufficient energy barrier will prevent metal-metal clustering. Ab-initio molecular dynamics (A.I.M.D.) simulations confirm the solidity of the structure at the highest desorption temperature. Therefore, we believe that the scandium decorated C$_{24}$ fullerene system is a thermodynamically stable, promising reversible high-capacity hydrogen storage device.