Hydrogen storage performance of 2LiH + MgB2 doped with hydrothermal-synthesized ZrO2 nanorods

In this study, we synthesized ZrO₂ nanorods through a hydrothermal process as a catalyst precursor for the reversible hydrogen storage reaction between 2LiH + MgB₂ and 2LiBH₄ + MgH_2. The 2LiH + MgB₂ composites doped with the ZrO₂ nanorods demonstrated superior and stable hydriding/dehydriding kinetics upon cycling. The XRD, SEM and HRTEM results revealed that the doped ZrO₂ nanorods were transformed into ZrB₂ nanoparticles with a size of a few nanometers during the first hydrogenation. The initial nanosize of the ZrO₂ catalyst precursor accounted for the formation of extremely fine ZrB₂ nanoparticles, which acted as heterogeneous nuclei of MgB₂. The present study provides a new route for performance enhancement of complex hydride composites through manipulating the nanostructure of catalysts.