In the present work, we study Sc atoms decorated aza-triphenylene based covalent organic framework (ScCOF) for hydrogen storage application by using the electronic structure calculations. A maximum of 18 Sc atoms are decorated on the single aza-triphenylene based covalent organic framework (COF) material with the binding energy of 4.3 eV/Sc-atom. We observe that a maximum of six H molecules are effectively adsorbed on each Sc atom in ScCOF with an adsorption energy of −0.36 eV/H molecule. The H molecules interact with the ScCOF through the Kubas interaction. The calculated H storage capacity is 8.43 % which meets the gravimetric density requirement set by the Department of Energy, United States of America (DOE-US) for H storage. The results obtained from the density of states (DOS) and Bader charge analysis show the charge transfer from the H molecules to ScCOF. Desorption temperature (T) for H molecules on the ScCOF is found to be 436 K. The results obtained from the diffusion energy barrier calculation and Ab-initio Molecular Dynamics (AIMD) simulation studies confirm the absence of metal cluster formation and structural stability of ScCOF at T. These results show the studied ScCOF is a promising material for reversible H storage application.

中文翻译：

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Sc修饰的氮杂苯并菲基共价有机骨架的储氢性能


在目前的工作中，我们通过电子结构计算研究了Sc原子修饰的氮杂苯并菲基共价有机骨架（ScCOF）在储氢方面的应用。单个氮杂苯并菲基共价有机骨架（COF）材料上最多装饰有18个Sc原子，结合能为4.3 eV/Sc原子。我们观察到最多六个 H 分子有效吸附在 ScCOF 中的每个 Sc 原子上，吸附能为 -0.36 eV/H 分子。 H 分子通过 Kubas 相互作用与 ScCOF 相互作用。计算出的氢气存储容量为8.43%，满足美国能源部（DOE-US）对氢气存储设定的重量密度要求。态密度 (DOS) 和 Bader 电荷分析获得的结果显示电荷从 H 分子转移到 ScCOF。 ScCOF 上 H 分子的解吸温度 (T) 为 436 K。扩散能垒计算和从头算分子动力学 (AIMD) 模拟研究获得的结果证实 ScCOF 不存在金属簇形成和结构稳定性这些结果表明所研究的 ScCOF 是一种有前途的可逆储氢应用材料。