▎ 摘　　要

Mg hydride is a competitive candidates for hydrogen storage based on its high gravimetric hydrogen capacity and accessibility. In this study, a small amount of KOH and graphene were added into MgH2 by high energy ball milling. MgH2 doped with both KOH and graphene has a greatly improved hydrogen storage performance. The existence of graphene and the in-situ formed KMgH3 and MgO decreased activation energy of MgH2 to 109.89 +/- 6.03 kJ/mol. The both KOH and graphene doped sample has a reversibly capacity of 5.43 wt % H-2 and can released H-2 as much as 6.36 times and 1.84 times faster than those of undoped sample and only KOH doped sample at 300 degrees C, respectively. The addition of graphene not only can provide more "H diffusion channels", but also can disperse the catalyst. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.