中国物理B ›› 2014, Vol. 23 ›› Issue (6): 67303-067303.doi: 10.1088/1674-1056/23/6/067303

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Theoretical study of molecular hydrogen and spiltover hydrogen storage on two-dimensional covalent-organic frameworks

刘秀英a, 何杰a, 于景新a, 栗正新b, 樊志琴a   

  1. a College of Science, Henan University of Technology, Zhengzhou 450000, China;
    b School of Material Science and Engineering, Henan University of Technology, Zhengzhou 450000, China
  • 收稿日期:2013-09-22 修回日期:2013-12-18 出版日期:2014-06-15 发布日期:2014-06-15
  • 基金资助:
    Project 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), and the Natural Science Foundation of Education Bureau of Henan Province, China (Grant Nos. 2011B140005 and 13A140195).

Theoretical study of molecular hydrogen and spiltover hydrogen storage on two-dimensional covalent-organic frameworks

Liu Xiu-Ying (刘秀英)a, He Jie (何杰)a, Yu Jing-Xin (于景新)a, Li Zheng-Xin (栗正新)b, Fan Zhi-Qin (樊志琴)a   

  1. a College of Science, Henan University of Technology, Zhengzhou 450000, China;
    b School of Material Science and Engineering, Henan University of Technology, Zhengzhou 450000, China
  • Received:2013-09-22 Revised:2013-12-18 Online:2014-06-15 Published:2014-06-15
  • Contact: Liu Xiu-Ying E-mail:liuxiuyingzx@126.com
  • Supported by:
    Project 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), and 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 Å, 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 Å, and PPy-COF. 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 proceed 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: hydrogen spillover, covalent-organic frameworks, hydrogen storage, grand canonical Monte Carlo simulation

Abstract: Molecular hydrogen and spiltover hydrogen storages on five two-dimensional (2D) covalent-organic frameworks (COFs) (PPy-COF, TP-COF, BTP-COF, COF-18 Å, 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 Å, and PPy-COF. 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 proceed 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.

Key words: hydrogen spillover, covalent-organic frameworks, hydrogen storage, grand canonical Monte Carlo simulation

中图分类号:  (Electronic structure of nanoscale materials and related systems)

  • 73.22.-f
36.40.-c (Atomic and molecular clusters) 71.15.Mb (Density functional theory, local density approximation, gradient and other corrections)