Low‐Temperature Synthesis of LiBH4 by Gas–Solid Reaction

Strikingly simple: The low‐temperature and solvent‐free synthesis of LiBH4 from LiH in a borane atmosphere at ambient pressures is reported. The results indicate that the formation of BH bonds is the limiting step for the formation of LiBH4 from the elements. Therefore, the use of diborane as a starting reactant allows one to circumvent the reaction barrier for the BB bond dissociation and explains the rather moderate synthesis conditions. magnified image The solvent‐free synthesis of LiBH4 from LiH in a borane atmosphere at 120 °C and ambient pressures is demonstrated. The source of borane is a milled LiBH4/ZnCl2 mixture, in which Zn(BH4)2 is generated by a metathesis reaction. The yield of the reaction of about 74 % LiBH4 shows that a bulk reaction is taking place upon borane absorption by LiH. This indicates that the formation of BH bonds is the limiting step for the formation of LiBH4 from the elements. Therefore, the use of diborane as a starting reactant allows one to circumvent the reaction barrier for the BB bond dissociation and explains the rather moderate synthesis conditions.