Enhanced dehydrogenation properties of MgH2 by the synergetic effects of transition metal carbides and graphene

Abstract

Abstract Transition metal carbides show remarkable catalysis for MgH2, and the addition of carbon materials can attach excellent cycling stability. In this paper, Mg-doped with transition metal carbides (TiC) and graphene (G) composite (denoted as Mg–TiC–G) is designed to assess the influence of TiC and graphene on the hydrogen storage performance of MgH2. The as-prepared Mg–TiC–G samples showed favorable dehydrogenation kinetics compared to the pristine Mg system. After adding TiC and graphene, the dehydrogenation activation energy of MgH2 decreases from 128.4 to 111.2 kJ mol−1. The peak desorption temperature of MgH2 doped with TiC and graphene is 326.5 °C, which is 26.3 °C lower than the pure Mg. The improved dehydrogenation performance of Mg–TiC–G composites is attributed to synergistic effects between catalysis and confinement.