%0 journal article
%@ 1932-7447
%A Le, T., Pistidda, C., Puszkiel, J., Castro Riglos, M., Karimi, F., Skibsted, J., Payandeh GharibDoust, S., Richter, B., Emmler, T., Milanese, C., Santoru, A., Hoell, A., Krumrey, M., Gericke, E., Akiba, E., Jensen, T., Klassen, T., Dornheim, M.

%D 2018
%J The Journal of Physical Chemistry C
%N 14
%P 7642-7655 
%R doi:10.1021/acs.jpcc.8b01850
%T Design of a Nanometric AlTi Additive for MgB2-Based Reactive Hydride Composites with Superior Kinetic Properties
%U https://doi.org/10.1021/acs.jpcc.8b01850
14 
%X Solid-state hydride compounds are a promising option for efficient and safe hydrogen-storage systems. Lithium reactive hydride composite system 2LiBH4 + MgH2/2LiH + MgB2 (Li-RHC) has been widely investigated owing to its high theoretical hydrogen-storage capacity and low calculated reaction enthalpy (11.5 wt % H2 and 45.9 kJ/mol H2). In this paper, a thorough investigation into the effect of the formation of nano-TiAl alloys on the hydrogen-storage properties of Li-RHC is presented. The additive 3TiCl3·AlCl3 is used as the nanoparticle precursor. For the investigated temperatures and hydrogen pressures, the addition of ∼5 wt % 3TiCl3·AlCl3 leads to hydrogenation/dehydrogenation times of only 30 min and a reversible hydrogen-storage capacity of 9.5 wt %. The material containing 3TiCl3·AlCl3 possesses superior hydrogen-storage properties in terms of rates and a stable hydrogen capacity during several hydrogenation/dehydrogenation cycles. These enhancements are attributed to an in situ nanostructure and a hexagonal AlTi3 phase observed by high-resolution transmission electron microscopy. This phase acts in a 2-fold manner, first promoting the nucleation of MgB2 upon dehydrogenation and second suppressing the formation of Li2B12H12 upon hydrogenation/dehydrogenation cycling.