The catalytic effect of an inert additive (SrTiO3) on the hydrogen storage properties of 4MgH2[sbnd]Na3AlH6.

Abstract Investigations on the catalytic effects of a non-reactive and stable additive, SrTiO 3 , on the hydrogen storage properties of the 4MgH 2 Na 3 AlH 6 destabilized system were carried out for the first time. The Na 3 AlH 6 compound and the destabilized systems used in the investigations are prepared using ball milling method. The doped system, 4MgH 2 Na 3 AlH 6 SrTiO 3 , had an initial dehydrogenation temperature of 145 °C, which 25 °C lower as compared to the un-doped system. The isothermal absorption and desorption capacity at 320 °C has increased by 1.2 wt% and 1.6 wt% with the addition of SrTiO 3 as compared to the 4MgH 2 Na 3 AlH 6 destabilized system. The decomposition activation energy of the doped system is estimated to be 117.1 kJ/mol. As for the XRD analyses at different decomposition stages, SrTiO 3 is found to be stable and inert. In addition to SrTiO 3 , similar phases are found in the doped and the un-doped system during the decomposition and dehydrogenation processes. Therefore, the catalytic effect of the SrTiO 3 is speculated owing to its ability to modify the physical structure of the 4MgH 2 Na 3 AlH 6 particles through pulverization effect. Highlights • H 2 storage properties of SrTiO 3 -doped 4MgH 2 Na 3 AlH 6 composite were investigated. • Doped with SrTiO 3 improved the H 2 sorption properties of 4MgH 2 Na 3 AlH 6. • The activation energy of the doped system is reduced to 117.1 kJ/mol. • SrTiO 3 give a pulverization effect for the SrTiO 3 -doped 4MgH 2 Na 3 AlH 6 composite. [ABSTRACT FROM AUTHOR]