Preparation and Catalytic Activity of a Novel Nanocrystalline ZrO2@C Composite for Hydrogen Storage in NaAlH4

Graphical Boosting hydrogen storage : In situ-synthesized nanocrystalline ZrO 2 @C exhibits good catalytic activity for hydrogen storage in NaAlH 4 . The NaAlH 4 –7 wt % ZrO 2 @C sample releases hydrogen starting from 126 °C and reabsorbs hydrogen starting from 54 °C, and these temperatures are lower by 71 and 36 °C, respectively, than those for pristine NaAlH 4 (see figure). Sodium alanate (NaAlH 4 ) has attracted intense interest as a prototypical high-density hydrogen-storage material. However, poor reversibility and slow kinetics limit its practical applications. Herein, a nanocrystalline ZrO 2 @C catalyst was synthesized by using Uio-66(Zr) as a precursor and furfuryl alcohol (FA) as a carbon source. The as-synthesized ZrO 2 @C exhibits good catalytic activity for the dehydrogenation and hydrogenation of NaAlH 4 . The NaAlH 4 -7 wt % ZrO 2 @C sample released hydrogen starting from 126 °C and reabsorbed it starting from 54 °C, and these temperatures are lower by 71 and 36 °C, respectively, relative to pristine NaAlH 4 . At 160 °C, approximately 5.0 wt % of hydrogen was released from the NaAlH 4 -7 wt % ZrO 2 @C sample within 250 min, and the dehydrogenation product reabsorbed approximately 4.9 wt % within 35 min at 140 °C and 100 bar of hydrogen. The catalytic function of the Zr-based active species is believed to contribute to the significantly reduced operating temperatures and enhanced kinetics.