Superior hydrogen storage properties of MgH2–10 wt.% TiC composite

The hydrogen storage performance of MgH2–10 wt.% TiC composite was investigated. The additive TiC nanoparticle led to a pronounced improvement in the de/hydrogenation kinetics of MgH2. The composite could dehydrogenate 6.3 wt.% at 573 K while the milled MgH2 only released 4.9 wt.% of hydrogen at the same condition. The improvement came from that the activation energy of dehydrogenation was decreased from 191.27 kJ mol−1 to 144.62 kJ mol−1 with the TiC additive. The MgH2–10 wt.% TiC composite also absorbed 6.01 wt.% (or 5.1 wt.%) of hydrogen under 1 MPa H2 at 573 K (or 473 K) in 3000 s. Even at 1 MPa H2 and 373 K, it could absorb 4.1 wt.% of hydrogen, but milled MgH2 could not absorb hydrogen at this condition. Additionally, the composite had good cycling stability, and its hydrogen capacity only decreased 3.3% of the first run after 10 de/hydrogenation cycles. The improved hydrogen storage properties were explained to the TiC particles embedded in the MgH2, which provided the pathways for the hydrogen diffusion into the MgH2–10 wt.% TiC composite.