Chemical Research in Chinese Universities ›› 2017, Vol. 33 ›› Issue (3): 422-429.doi: 10.1007/s40242-017-6436-z

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Enhancement of Hydrogen Sorption on Metal (Ni, Rh, Pd) Functionalized Carbon Nanotubes: a DFT Study

XIAO Lu1, CHU Wei1, SUN Wenjing2, XUE Ying1, JIANG Chengfa1   

  1. 1. School of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China;
    2. China-America Cancer Research Institute, Key Laboratory for Medical Molecular Diagnostics of Guangdong Province, Guangdong Medical University, Dongguan 523808, P. R. China
  • Received:2016-11-01 Revised:2017-03-07 Online:2017-06-01 Published:2017-04-11
  • Contact: JIANG Chengfa,E-mail:jiangcf@scu.edu.cn E-mail:jiangcf@scu.edu.cn
  • Supported by:

    Supported by the National Natural Science Foundation of China(No.201476145) and the National Basic Research Program of China(No.2011CB201202).

Abstract:

Hydrogen interacted with pristine single-walled carbon nanotubes(SWNTs) and single/dimer metal doped ones(M-CNTs) was investigated via density functional theory(DFT) simulations. The most stable configurations of Ni, Rh, Pd on SWNTs were identified. The interaction of H2 molecules with pristine SWNTs and M-CNTs was investigated. The results show that H2 molecules can be adsorbed on the pristine SWNTs via a weak physical interaction, which is much weaker than those of H2 molecules with M-CNTs by chemisorption. Each Ni, Rh and Pd doped SWNTs can respectively chemisorb three, two, or one H2 molecules and the H-H bond of H2 molecule is elongated. Furthermore, the H2 molecule could be dissociated owing to the presence of the Ni-Ni bond for Ni dimer doped SWNT, forming new Ni-H bonds. While such a dissociation could not be observed on Rh2/Pd2-CNT samples. Density of state(DOS) results show that the s orbital of hydrogen can hybridize with the d orbital of metal atom, resulting in the stronger inteaction between H2 and M-CNTs, impying that the hydrogen storage capacity could be enhanced in the presence of M-CNTs. The comparison of the interaction mechanism among different metals doped CNTs can screen out the most effective hydrogen-adsorption materials and the design of the related materials by computational approaches.

Key words: Hydrogen sorption, Carbon nanotube, Metal doped, Density functional theory