Improvement of hydrogen storage performance of MgH2 by MnMoO4 rod composite catalyst.

At present, catalyst doping has been widely concerned by researchers as an effective method to improve the hydrogen storage performance of MgH 2. Herein, it is confirmed that MnMoO 4 rod catalyst can effectively improve the hydrogen storage performance of MgH 2. According to the experimental results, MgH 2 +10 wt%MnMoO 4 composite material starts dehydrogenation at about 220 °C, which is about 140 °C lower than MgH 2 without additives. The initial dehydrogenation capacity of 6 wt% can be reached within 10min at 300 °C. After complete dehydrogenation, H 2 can be absorbed below 55 °C, and 4.34 wt% H 2 can be absorbed within 15 min at 150 °C and 3 MPa hydrogen pressure. In addition, the activation energy of dehydrogenation of MgH 2 decreased about 45 kJ mol−1. Furthermore, hydrogen storage capacity of MgH 2 can still be maintained at 5.85 wt% after 20 cycles. The synergy between the in-situ formed Mn and MgMo 2 O 7 may help promote the dissociation and diffusion of H 2 along the Mg/MgH 2 interface, thereby improving the hydrogen storage performance of MgH 2. [Display omitted] • MgH 2 –MnMoO 4 composite system was reported for the first time. • MgH 2 +10 wt%MnMoO 4 composite material starts dehydrogenation at about 220 °C. • MgH 2 –MnMoO 4 composites showed promising kinetic properties. • MgO, Mn and MgMo 2 O 7 were formed in situ during the reaction. [ABSTRACT FROM AUTHOR]