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. MgH2 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, TiO2_ZnTiO3 with carbon nanotubes (CNTs) is successfully synthesized by simple hydrothermal, calcination, and mechanical ball milling methods. In particular, MgH2+10 wt% TiO2_ZnTiO3@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 MgH2. 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. •Successful preparation of TiO2_ZnTiO3@CNTs and its addition as catalyst to MgH2.•TiO2_ZnTiO3@CNTs can significantly reduce the operating temperature of MgH2.•Enhancing the rate of hydrogen de/absorption from MgH2.•Improvement of particle agglomeration and cyclic stability of MgH2.