%0 journal article
%@ 0360-3199
%A Valentoni, A.,Garroni, S.,Pistidda, C.,Masolo, E.,Napolitano, E.,Moretto, P.,Dornheim, M.,Mulas, G.,Enzo, S.
%D 2014
%J International Journal of Hydrogen Energy
%N 30
%P 17075-17082 
%R doi:10.1016/j.ijhydene.2014.07.169
%T New insights into the thermal desorption of the 2LiNH2 + KBH4 + LiH mixture
%U https://doi.org/10.1016/j.ijhydene.2014.07.169
30 
%X In situ two-dimensional synchrotron X-ray powder diffraction investigation combined with Rietveld method data analysis were performed in order to yield a complete and quantitative phases structure evolution of the polycrystalline mixture 2LiNH2 + KBH4 + LiH during H2 desorption. While a first-principles, purely thermodynamics approach of the system predicted a single dehydrogenation step reaction at relatively low temperatures, it is assessed experimentally that the reaction occurs in two steps with first the formation of Li2NH at ca. 230 °C due to the reaction between LiNH2 and LiH plus hydrogen and ammonia evolution, followed by an additional reaction of the resulting phases with KBH4 at 360 °C, which releases hydrogen and leads to the formation of the monoclinic and tetragonal Li3BN2 polymorphs. Besides pointing out possible limits of a purely thermodynamics approach inevitably relying exact knowledge of experimental quantities, it is concluded that before assuming it viable for on-board vehicle use, additional stoichiometries may be worth of investigation in order to assess any existence of lower hydrogen desorption temperature of such system.