Enhanced dehydrogenation performance of NaAlH 4 by the addition of spherical SrTiO 3

Summary Sluggish sorption kinetics, high decomposition temperature and unsatisfactory cycles of hydrogen release and uptake (reversibility) remain big challenges for using sodium alanate (NaAlH 4 ) as a practical hydrogen storage medium. In solid‐state hydrogen storage materials, especially NaAlH 4 , finding effective catalysts and using mechanical treatment represent promising solutions to overcome the drawbacks of NaAlH 4 . For the first time, in this work, the influence of spherical strontium titanate (SrTiO 3 ) on the dehydrogenation behavior of NaAlH 4 has been investigated. Here, we report that the onset desorption temperature is decreased and the desorption kinetics of NaAlH 4 is enhanced with the addition of 10 wt% of spherical SrTiO 3 catalyst. Using Kissinger's technique, the apparent activation energy of the NaAlH 4 doped with 10 wt% SrTiO 3 composites for the two‐step dehydrogenation was identified as 79 and 92 kJ/mol, which was decreased significantly from that of undoped NaAlH 4 (116 and 122 kJ/mol, respectively). Scanning electron microscopy results indicated that the NaAlH 4 particle sizes decreased by milling with SrTiO 3 . X‐ray diffraction results indicated that SrTiO 3 did not react or change during the milling and desorption (heating) processes. The improvements in the desorption properties of NaAlH 4 resulted from the ability of SrTiO 3 to reduce the physical structure of the NaAlH 4 during the ball milling process.