Evaluation of the standard enthalpies and isobaric potentials of the formation of certain complex hydrides

Development of amidoboranes for hydrogen storage

“…Borohydrides can be synthesized by reacting metal hydrides and diborane through the reaction (19). [94][95][96] MH n + n/2B 2 H 6 -M(BH 4 ) n , (19) with M being a metal and n being the valence state of metal.…”

Structure of unsolvated magnesium borohydride Mg(BH4)2

“…However, the poor quality of the diffraction data precluded determination of the crystal structure. Empirical calculation of the enthalpy of decomposition of Mg(BH 4 ) 2 (Sarner, 1966;Kuznetsov & Dymova, 1971) gave the very attractive value of $ 40 kJ mol À1 H 2 , which would suggest that the hydrogen release should be reversible at moderate temperatures. Interest in this system has stimulated a number of theoretical works, including some predictions of crystal structures (Charkin et al, 1987;Vajeeston et al, 2006;Majzoub & Ozolins, 2006;Bonaccorsi et al, 1991;.…”

A study of the effect of the addition of nanostructured carbonaceous catalysts in the dehydrogenation mechanism of magnesium borohydride

“…Magnesium borohydride Mg(BH 4 ) 2 is well known for its high gravimetric (14.9 wt%) and volumetric (113 g-H 2 per L) hydrogen densities, besides the favorable enthalpy of decomposition was estimated empirically to be about 40 kJ per mol H 2 . 6,7 As experimentally observed 4 the reaction occurs via several stages with the formation of intermediate magnesium polyboranes, which eventually transforms into the most stable magnesium dodecaboranate and ultimately ends with the formation of MgB 2 . The formation of dodecaboranate actually is common for all metal borohydrides, and the existence of multiple steps with different enthalpies makes the task of rehydrogenation very difficult.…”