Metallic Glassy V45Zr20Ni20Cu10Al3Pd2 Alloy Powders for Superior Hydrogenation/Dehydrogenation Kinetics of MgH2

Nanocrystalline MgH2 powders with an average grain size of 7 nm in diameter were synthesized via reactive ball milling (RBM) approach, using a high energy ball mill operated under a high hydrogen pressure of 50 bar. The as-synthesized MgH2 powders obtained after 200 h of RBM showed slow hydrogenation/dehydrogenation kinetics. In order to improve the kinetics behaviors of this binary metal hydride system, multicomponent-metallic glassy V45Zr20Ni20Cu10Al3Pd2 alloy powders fabricated by mechanical alloying under liquid nitrogen were used as a heterogeneous catalytic agent. For the purpose of the present study, the MgH2 powders were doped with 10 wt.% of the metallic glassy powders and ball-milled for 50 h. The results have shown that the decomposition temperature of as-doped MgH2 with 10 wt.% of V45Zr20Ni20Cu10Al3Pd2 powders was 308.9 degrees C, being far below than that one measured for pure MgH2 (416 degrees C). This new nanocomposite system possessed outstanding properties, indexed by the fast kinetics of absorption and desorption of 5.5 wt. % H-2 within 200 s at a rather low temperature (180 degrees C). (C) 2018 Elsevier Ltd. All rights reserved.