Hydrogen storage properties for Mg-Zn-Y quasicrystal and ternary alloys

摘要

Three Zn-Mg-Y alloys with nominal compositions of Zn50Mg42Y8 and Zn60Mg30Y10 were prepared by induction melting or gas atomisation. XRD and SEM analysis shows samples ZMY-1 and ZMY-2 consisted of multiple phases including icosahedral quasicrystal (QC) i-phase, hexagonal H-phase and Mg7Zn3, whilst ZMY-3 contained QC only. The hydrogen storage properties of the Zn-Mg-Y quasicrystal and ternary alloys were investigated for the first time. The quasicrystal sample ZMY-3 hydrogenated at 300 degrees C had 0.3 wt.% capacity and the DSC decomposition peak temperature was 503 degrees C. Amongst the three samples, the highest hydrogen storage capacity (0.9 wt.%) and the lowest decomposition peak temperature (445 degrees C) was achieved by sample ZMY-1. The pressure-composition-isotherm (PCI) curve of ZMY-1 sample showed a flat plateau gave a plateau pressure of 3.5 bar at 300 degrees C, which indicates a lower dehydrogenation enthalpy than MgH2. (C) 2015 Elsevier B.V. All rights reserved.