Confined NaAlH nanoparticles inside CeO hollow nanotubes towards enhanced hydrogen storage.

NaAlH has been widely regarded as a potential hydrogen storage material due to its favorable thermodynamics and high energy density. The high activation energy barrier and high dehydrogenation temperature, however, significantly hinder its practical application. In this paper, CeO hollow nanotubes (HNTs) prepared by a simple electrospinning technique are adopted as functional scaffolds to support NaAlH nanoparticles (NPs) towards advanced hydrogen storage performance. The nanoconfined NaAlH inside CeO HNTs, synthesized via the infiltration of molten NaAlH into the CeO HNTs under high hydrogen pressure, exhibited significantly improved dehydrogenation properties compared with both bulk and ball-milled CeO HNTs-catalyzed NaAlH. The onset dehydrogenation temperature of the NaAlH@CeO composite was reduced to below 100 °C, with only one main dehydrogenation peak appearing at 130 °C, which is 120 °C and 50 °C lower than for its bulk counterpart and for the ball-milled CeO HNTs-catalyzed NaAlH, respectively. Moreover, ∼5.09 wt% hydrogen could be released within 30 min at 180 °C, while only 1.6 wt% hydrogen was desorbed from the ball-milled NaAlH under the same conditions. This significant improvement is mainly attributed to the synergistic effects contributed by the CeO HNTs, which could act as not only a structural scaffold to fabricate and confine the NaAlH NPs, but also as an effective catalyst to enhance the hydrogen storage performance of NaAlH.