▎ 摘　　要

In order to mitigate the disadvantage of the Mg hydrides, several studies have been conducted that have used MgHx intermixed with carbon. Graphene is a kind of carbon allotrope that is easily subject to a desorption reaction at low temperatures because such a reaction is exothermic. In this work, an MgHx-graphene mixture has been prepared by reactive mechanical grinding. The synthesized powder was characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and simultaneous thermogravimetric (TG) and differential scanning calorimetric (DSC) analyses. The hydrogenation behaviors were evaluated using a Sievert's type automatic pressure-composition-temperature (PCT) apparatus without activation treatment. From the characteristics of the absorption kinetics and the curves observed, the role of graphene as a catalyst in hydrogen absorption was determined. According to the results of the PCI curve, the available hydrogen storage amounts for MgHx-5 wt% graphene composites had maximum values of 3.69, 5.09, and 5.72 wt% at 423, 523, and 623 K, respectively. Those values for MgHx-10 wt% graphene were 5.08, 5.45, and 5.83 wt% at 423, 523, and 673K, respectively.