Nanosized SrTiO₃ Catalyzes Hydrogen Sorption of MgH₂

Nanosized SrTiO3, a common photocatalyst that enhances water splitting for hydrogen production, has been synthesized to catalyze the reversible hydrogen gas–solid reaction of MgH2. Compared to the pure MgH2, the milled MgH2-SrTiO3 composite shows significantly enhanced hydrogen storage properties, absorbing 3.5 wt % H2 within 1 min at room temperature and releasing 6.1 wt % H2 within 9 min at 250 °C. The activation energy for dehydrogenation is 82.91 kJ/mol, which is 52.09 kJ/mol lower than that of as-milled MgH2. The composite retains a capacity of 5.47 wt % after 40 cycles of dehydrogenation at 250 °C. The catalytic mechanism of nanosized SrTiO3 was discussed. Therefore, like anatase TiO2 photocatalysts, SrTiO3 shows an excellent catalytic effect to enhance the hydrogen sorption of MgH2 at significantly lower temperatures. A significant number of photocatalytsts have great potential to enhance the hydrogen sorption of Mg, making them promising candidates for solid-state hydrogen storage materials.