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

Abstract

At present, catalyst doping has been widely concerned by researchers as an effective method to improve the hydrogen storage performance of MgH2. Herein, it is confirmed that MnMoO4 rod catalyst can effectively improve the hydrogen storage performance of MgH2. According to the experimental results, MgH2+10 wt%MnMoO4 composite material starts dehydrogenation at about 220 °C, which is about 140 °C lower than MgH2 without additives. The initial dehydrogenation capacity of 6 wt% can be reached within 10min at 300 °C. After complete dehydrogenation, H2 can be absorbed below 55 °C, and 4.34 wt% H2 can be absorbed within 15 min at 150 °C and 3 MPa hydrogen pressure. In addition, the activation energy of dehydrogenation of MgH2 decreased about 45 kJ mol−1. Furthermore, hydrogen storage capacity of MgH2 can still be maintained at 5.85 wt% after 20 cycles. The synergy between the in-situ formed Mn and MgMo2O7 may help promote the dissociation and diffusion of H2 along the Mg/MgH2 interface, thereby improving the hydrogen storage performance of MgH2.