Hydrogen storage properties of MgH2 modified by efficient Co3V2O8 catalyst

Developing medium temperature hydrogen storage materials is important for the practical application of the Studies have demonstrated that V-based catalysts exhibit exceptional catalytic activity in the dehydrogenation of MgH 2 at medium levels. However, the V-base catalysts primarily concentrates on hydrogen desorption, and there is a necessity for further enhancement of hydrogen absorption properties. To solve this problem, herein we prepared a bimetallic oxide. Co can enhance the hydrogen absorption and desorption properties of MgH 2 as the catalyst and it influences the performance of hydrogen absorption more obviously than the hydrogen desorption performance. It is found that MgH 2 catalyzed by Co 3 V 2 O 8 can absorb 1.31 wt% hydrogen within 30 min even under room temperature and can release 3.41 wt% hydrogen within 120 min at temperatures as low as 225 °C. The activation energy of MgH 2 -6 wt.%Co 3 V 2 O 8 is determined to 68.5 kJ/mol, which is 50.2 % lower than that of Ball-MgH 2 . XRD combined with TEM measurements revealed that the in-situ formed Co and V 2 O 3 can weaken the H H and Mg H bonds respectively to improve the hydrogen storage properties of MgH 2 . These discoveries provide guideline of the further design of high efficiency catalysts for Mg-based hydrogen storage materials.