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Synergetic effect of Ni and Nb2O5 on dehydrogenation properties of nanostructured MgH2 synthesized by high-energy mechanical alloying

Simchi, H ; Sharif University of Technology | 2009

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  1. Type of Document: Article
  2. DOI: 10.1016/j.ijhydene.2009.07.038
  3. Publisher: 2009
  4. Abstract:
  5. Nanostructured MgH2-Ni/Nb2O5 nanocomposite was synthesized by high-energy mechanical alloying. The effect of MgH2 structure, i.e. crystallite size and lattice strain, and the presence of 0.5 mol% Ni and Nb2O5 on the hydrogen-desorption kinetics was investigated. It is shown that the dehydrogenation temperature of MgH2 decreases from 426 °C to 327 °C after 4 h mechanical alloying. Here, the average crystallite size and accumulated lattice strain are 20 nm and 0.9%, respectively. Further improvement in the hydrogen desorption is attained in the presence of Ni and Nb2O5, i.e. the dehydrogenation temperature of MgH2/Ni and MgH2/Nb2O5 is measured to be 230 °C and 220 °C, respectively. Meanwhile, the dehydrogenation starts at 200 °C in MgH2-Ni/Nb2O5 system, revealing synergetic effect of Ni and Nb2O5. The mechanism of the catalytic effect is presented. © 2009 Professor T. Nejat Veziroglu
  6. Keywords:
  7. Catalytic effects ; Dehydrogenation properties ; Desorption kinetics ; High energy ; Hydrogen absorbing materials ; Hydrogen desorption ; Lattice strain ; Metal hydrides ; Nano-structured ; Synergetic effect ; Crystallite size ; Dehydrogenation ; Desorption ; Hydrides ; Hydrogen ; Lithium batteries ; Mechanical alloying ; Metallurgy ; Microstructure ; Nanocomposites ; Nickel ; Niobium ; Nanostructures
  8. Source: International Journal of Hydrogen Energy ; Volume 34, Issue 18 , 2009 , Pages 7724-7730 ; 03603199 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0360319909011045