Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (10): 2207-2214.doi: 10.3866/PKU.WHXB201307191

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Molecular Simulation on Hydrogen Storage Capacities of Porous Metal Organic Frameworks

WU Xuan-Jun, ZHENG Ji, LI Jiang, CAI Wei-Quan   

  1. School of Chemical Engineering, Wuhan University of Technology, Wuhan 430070, P. R. China
  • Received:2013-05-20 Revised:2013-07-15 Published:2013-09-26
  • Contact: CAI Wei-Quan E-mail:wqcai@home.ipe.ac.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51142002, 51272201) and Fundamental Research Funds for the Central Universities, China (2012142, 2013-II-014).

Abstract:

The adsorption equilibriumproperties of H2 molecules in various metal-organic frameworks (MOFs) including IRMOF-61, IRMOF-62, and IRMOF-1 were studied using the grand canonical Monte Carlo (GCMC) simulation method with the optimized parameters obtained using the DREIDING force field. The calculated parameters could exactly reproduce the adsorption isotherms of H2 molecules in IRMOF-62. However, they may underestimate the adsorption isothermof H2 molecules in IRMOF-61 at lowpressure. The H2 storage capacities of IRMOF-61 and IRMOF-62 with interpenetrating frameworks were not significantly higher than that of IRMOF-1 at roomtemperature. H2 molecules were preferentially adsorbed near Zn4O units, which were located close to the benzene rings, according to the probability density distribution of H2 molecules in the above MOFs under adsorption equilibriumconditions at 77 K, 100 kPa, and 3.0 MPa. For the MOFs with interpenetrating frameworks, the area with preferential adsorption sites for H2 molecules is smaller and more scattered than the MOF without because of their smaller cavity sizes. The organic linker should be of appropriate length to promote the formation of an interpenetrating framework, which can enhance the interaction between the framework and H2 molecules, and thus improve H2 storage capacity. If the organic linker is too long, it will decrease the adsorption capacity of the MOF for H2 because more corners unable to adsorb H2 are formed.

Key words: MOFs, Porous material, GCMC simulation, Hydrogen storage, Isothermal adsorption

MSC2000: 

  • O641