Destabilized dehydrogenation reaction of LiBH4 by AlF3

Abstract: In this work, the composites of LiBH4 and AlF3 were prepared and their hydrogen storage properties were investigated. The AlF3 addition to LiBH4 resulted in significant decreases in dehydrogenation temperature. All the xLiBH4 +AlF3 (x =1, 2, 3, 5) composites started to release hydrogen from about 100°C. The dehydrogenation of the composites was accomplished through several steps, depending on the molar ratio of LiBH4 to AlF3. A new phase Li3AlF6 was formed during the first dehydrogenation step, which further reacted with LiBH4. AlB2 was formed only at temperatures higher than 300°C. Li2B12H12 was detected as an intermediate. The dehydrogenation reactions have significantly reduced and thus favorable enthalpy changes. However, the reversibility of the composites needs to be improved. [Copyright &y& Elsevier]