TiO2_ZnTiO3 with carbon nanotubes catalytically improve the hydrogen storage characteristics of MgH2

Solid-state hydrogen storage technology is attracting considerable attention in the field of energy storage as a potential solution for clean energy storage and transmission. MgH 2 is one of the most promising materials for solid-state hydrogen storage today. However, its practical applications are limited by high dehydrogenation temperature, slow rate, and low cyclic stability. In this paper, TiO 2 _ZnTiO 3 with carbon nanotubes (CNTs) is successfully synthesized by simple hydrothermal, calcination, and mechanical ball milling methods. In particular, MgH 2 +10 wt% TiO 2 _ZnTiO 3 @CNTs exhibited excellent hydrogen storage properties during cycling compared to the composites without added CNTs. The composite material can dehydrogenate up to 6.1 wt% in 10 min at 300 °C, approximately one order of magnitude higher than the rate of pure MgH 2 . And the corresponding whole dehydrogenation process can be accomplished in 15 min. The starting hydrogen absorption temperature of the composite material is less than 50 °C, and the activation energy is significantly reduced. Relevant tests indicate that the new phase exists stably during the dehydrogenation/absorption process, which helps promote the dissociation and diffusion of hydrogen atoms. This study broadens the application of catalysts in hydrogen storage and provides a strategy to promote the sustainable utilization and development of clean energy.