Review Article

Metastable Metal Hydrides for Hydrogen Storage

Table 2

A few examples of unstable and metastable aluminum-based hydrides showing hydrogen weight percent and the initial decomposition temperature (in many cases full hydrogen desorption occurs over multiple steps that occur at higher temperatures). It is also worth noting that the decomposition temperatures listed identify the temperature at which significant H2 evolution occurs and may be lower than the exothermic or endothermic peaks observed in calorimetric measurements.

Alanes and hexahydride alanatesWt.%HDecomposition temperatureTetrahydride alanatesWt.%HDecomposition temperature

α-AlH3 [1828]10.1100°CLiAlH4 [2931]10.5120°C
α ′-AlH3 [21]10.190°CCuAlH4 [32]−70°C
β-AlH3 [19, 20, 22]10.180°CAgAlH4 [32]−50°C
γ-AlH3 [19, 20, 2328]10.180°C [32]20°C
AlH6 [2931, 33, 34]11.1160°C [35, 36]110°C
[37, 38]150°C
[32]25°C
[32, 39]<−45°C
LiMg [37]100°C
CaMg [38]125°C
In [32]−40°C
Ce [32]25°C
Ti [32, 40]−85°C
Sn [32]−40°C