CIESC Journal ›› 2015, Vol. 66 ›› Issue (7): 2540-2546.DOI: 10.11949/j.issn.0438-1157.20150117

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Adsorption mechanism of H2 on covalent organic frameworks

YANG Xiao, LIU Jing, HU Jianbo   

  1. State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
  • Received:2015-01-23 Revised:2015-04-13 Online:2015-07-05 Published:2015-07-05
  • Supported by:

    supported by the Foundation of State Key Laboratory of Coal Combustion (FSKLCCB1502).

氢气在共价有机骨架材料中的吸附机理

杨宵, 刘晶, 胡建波   

  1. 华中科技大学煤燃烧国家重点实验室, 湖北 武汉 430074
  • 通讯作者: 刘晶
  • 基金资助:

    煤燃烧国家重点实验室自主研发基金项目(FSKLCCB1502)。

Abstract:

Covalent organic frameworks (COFs) are considered as a new type of adsorbing material for hydrogen. In this work, density functional theory (DFT) has been applied to investigate the adsorption mechanism of H2 on seven main clusters of COFs, and GGA/PBE is used in the calculation. The results indicate that the center of benzene ring is the most favorable site when H2 molecular attacks vertically, in addition the center and oxygen atom of B3O3 ring are more favorable when H2 molecular attacks parallelly. The increase of carbon atom number on organic cluters would be beneficial for adsorption of H2. By calculation of different adsorption configurations for two H2 molecules on COF-10 and COF-105, it is found that a cooperative effect between H2 adsorption on these two COFs could be exist. Doping of alkali metals (Li, Na, K) and substitution of organic functional groups (methyl, sulfhydryl, amino) on COFs can significantly enhance the adsoroption energy, indicating that these chemical modifications are an effective way for enhancement of hydrogen adsorption capacity of COFs.

Key words: hydrogen, covalent organic frameworks, adsorption, density functional theory, molecular simulation, chemical modification

摘要:

共价有机骨架材料(COFs)是一种新型的储氢材料。采用密度泛函理论研究了COFs的7种主要团簇对H2的吸附机理,计算中选用GGA/PBE泛函。结果表明,当H2垂直接近时,团簇中心苯环为最优先吸附位,当H2平行接近时,硼氧环的中心以及氧原子上为最优先的吸附位。有机链团簇C原子数目的增加有利于对氢气的吸附,多个H2分子在COF-10和COF-105团簇的吸附主要属于协同吸附。对COFs进行碱金属(Li、Na、K)掺杂和官能团替代(甲基—CH3、巯基—SH、氨基—NH2)改性,发现H2吸附能得到显著提高,说明改性是提高COFs材料H2吸附能力的有效途径。

关键词: 氢气, 共价有机骨架材料, 吸附, 密度泛函理论, 分子模拟, 化学改性

CLC Number: