Kinetic Enhancement in the Sorption Properties by Forming Mg–x wt % ZrCrCu Composites

Composite formation with Zr-based Laves phase alloys, especially the ZrCr 2 family, is an effective method to improve the hydriding properties of MgH 2 . The present paper describes a systematic study of the reaction pathway of Mg– x wt % ZrCrCu composites ( x = 25, 50) in terms of their structural, morphological, and hydrogenation properties. XRD and SEM results show no interaction between Mg and the ZrCrCu alloy phase during composite preparation by high-energy ball-milling. However, hydriding/annealing cycles lead to the formation of the Mg 2 Cu phase at grain boundaries of the Mg–ZrCrCu matrix. This Mg 2 Cu phase does not interact with the hydrogen at the studied condition, but provides several diffusion paths and stable nucleation sites for the formation of MgH 2, and thus enhances the sorption kinetics. Pressure composition temperature (PCT) analysis shows a reduction in desorption temperature down to 250 °C for these composites.