Enhanced hydrogen storage properties of MgH2 by the synergetic catalysis of Zr0.4Ti0.6Co nanosheets and carbon nanotubes

Abstract Transition metal nanoparticles have shown great catalytic effect on MgH2, yet excellent cyclic stability can be attached due to the addition of carbon nanotubes. In this paper, MgH2 + 10 wt% Zr0.4Ti0.6Co /5 wt% Carbon nanotubes (CNTs) composite is designed to investigate the synergistic modification of Zr0.4Ti0.6Co nanosheets and carbon nanotubes on the hydrogen storage performance of MgH2. Compared with pure MgH2, the initial hydrogen release temperature of MgH2 + 10 wt% Zr0.4Ti0.6Co /5 wt% CNTs composite decreases to 180 °C and the composite can quickly release 90% H2 within 10 min at 300 °C. In addition, the completely dehydrogenated sample can absorb 3.51 wt% H2 within 20 min under 3 Mpa hydrogen pressure at 125 °C. Ulteriorly, the activation energy values of dehydrogenation and rehydrogenation of MgH2 decrease to 70.5 ± 7.8 kJ/mol and 35.8 ± 3.8 kJ/mol on account of the presence of 10 wt% Zr0.4Ti0.6Co/5 wt% CNTs, which reasonably explains the remarkable reduction of the temperature for hydrogen sorption. Furthermore, the MgH2 + 10 wt% Zr0.4Ti0.6Co /5 wt% CNTs composite shows excellent cycling performance, indicative of potential application in practical hydrogen storage in the nearest future.