| Theoretical study of molecular hydrogen and spiltover hydrogen storage on two-dimensional covalent-organic frameworks |
| |
| 作者姓名： | 刘秀英 何杰 于景新 栗正新 樊志琴 |
| |
| 基金项目： | supported by the National Natural Science Foundation of China(Grant Nos.11247275 and 11304079);the Young Core Instructor of the Higher Education Institutions of Henan Province;the Special Foundation for Fostering Technologic Innovative Talents of Henan University of Technology,China(Grant No.2012CXRC16);the Natural Science Foundation of Education Bureau of Henan Province,China(Grant Nos.2011B140005 and 13A140195) |
| |
| 摘 要： | Molecular hydrogen and spiltover hydrogen storages on five two-dimensional （2D） covalent-organic frameworks （COFs） （PPy-COF, TP-COF, BTP-COF, COF-18 A, and HHTP-DPB COF） are investigated using the grand canonical Monte Carlo （GCMC） simulations and the density functional theory （DFT）, respectively. The GCMC simulated results show that HHTP-DPB COF has the best performance for hydrogen storage, followed by BTP-COF, TP-COF, COF-18 A, and PPy-COE However, their adsorption amounts at room temperature are all too low to meet the uptake target set by US Department of Energy （US-DOE） and enable practical applications. The effects of pore size, surface area, and isosteric heat of hydrogen on adsorption amount are considered, which indicate that these three factors are all the important factors for determining the H2 adsorption amount. The chemisorptions of spiltover hydrogen atoms on these five COFs represented by the cluster models are investigated using the DFT method. The saturation cluster models are constructed by considering all possible adsorption sites for these cluster models. The average binding energy of a hydrogen atom and the saturation hydrogen storage density are calculated. The large average binding energy indicates that the spillover process may pro- ceed smoothly and reversibly. The saturation hydrogen storage density is much larger than the physisorption uptake of H2 molecules at 298 K and 100 bar （1 bar = 105 Pa）, and is close to or exceeds the 2010 US-DOE target of 6 wt% for hydrogen storage. This suggests that the hydrogen storage capacities of these COFs by spillover may be significantly enhanced. Thus 2D COFs studied in this paper are suitable hydrogen storage media by spillover.
|
| 关 键 词： | 储氢性能 分子氢 框架理论 共价 二维 密度泛函理论 美国能源部 DFT方法 |
Theoretical study of molecular hydrogen and spiltover hydrogen storage on two-dimensional covalent-organic frameworks |
| |
| Abstract: | hydrogen spillover, covalent-organic frameworks, hydrogen storage, grand canonical Monte Carlo simulation |
| |
| Keywords: | hydrogen spillover covalent-organic frameworks hydrogen storage grand canonical Monte Carlo simulation |
| 本文献已被 CNKI 维普 等数据库收录！ |
|
