A comparison study of hydrogen storage performances of as-milled YMg11Ni alloy catalyzed by CeO2 and MoS2.

The microstructures, hydrogen storage thermodynamics and kinetics, and non-isothermal dehydrogenation performances of YMg 11 Ni + 5 wt% M (M = CeO 2 , MoS 2 ) alloys prepared by ball milling were investigated. The results reveal that there exist a nanocrystalline and amorphous structure in all experimental alloys. The CeO 2 catalyzed alloy shows a larger hydrogen absorption capacity and faster hydriding rate as compared with the MoS 2 catalyzed one. The onset hydrogen desorption temperature of M = CeO 2 alloy is lower than that of M = MoS 2 alloy. The hydrogen desorption property of M = CeO 2 alloy is superior to that of M = MoS 2 alloy. The dehydrogenation activation energy ( E de ) is in the order of E de (CeO 2 ) < E de (MoS 2 ), which is responsible for the M = CeO 2 alloy possessing the much faster hydrogen desorption rate. The hydrogen desorption enthalpy change (Δ H de ) is in the order of Δ H de (CeO 2 ) < Δ H de (MoS 2 ). [ABSTRACT FROM AUTHOR]