Modification of COF-108 via impregnation/functionalization and Li-doping for hydrogen storage at ambient temperature

Zhipeng Ke, Yuanyuan Cheng, Siyuan Yang, Fan Li, Lifeng Ding*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

30 Citations (Scopus)

Abstract

Post-modification approaches such as Li-doping, impregnation, and functionalization are promising methods to enhance H2 adsorption in metal–organic frameworks (MOFs) and covalent-organic frameworks (COFs). In this work, we propose a two-step method to modify COF-108 with the aim to enhance its hydrogen storage capacity at ambient temperature. First, we geometrically modified COF-108 through C60 impregnation or aromatic ring grafting. Subsequently, we surface doped the modified COF-108 with Li atoms. COF-108 is the lightest 3D crystalline material ever reported and it is a promising H2 storage material. Our grand canonical Monte Carlo (GCMC) simulations demonstrated that the combination of Li-doping with C60 impregnation or aromatic ring grafting can potentially increase the volumetric H2 adsorption capacity of COF-108 to reach a total H2 adsorption capacity close to the U.S. DOE target. One of the Li-doped C60-impregnated (Li6C60) COF-108 (with 8 Li6C60 moieties impregnated) showed an absolute H2 uptake beyond the 2010 DOE target (45.6 mg/g and 28.6 g/cm3) at 233 K and 100 bar. Impregnation of C60 and/or grafting of aromatic rings not only increased the density of doped Li in the modified COF-108 but also created more overlapped potential interaction with H2, which resulted in higher number of H2 adsorption sites per unit volume as compared to the unmodified material.

Original languageEnglish
Pages (from-to)11461-11468
Number of pages8
JournalInternational Journal of Hydrogen Energy
Volume42
Issue number16
DOIs
Publication statusPublished - 20 Apr 2017

Keywords

  • Aromatic rings grafting
  • Covalent organic framework
  • Fullerene impregnation
  • Grand canonical Monte Carlo
  • Hydrogen storage
  • Li doping

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