Reversible Hydrogen Decomposition of KAlH4.

Abstract We report that potassium aluminum tetrahydride, KAlH4, exhibits a rapid reversible hydrogen decomposition reaction without any aid of external catalysts. This is significantly different from the reaction mechanism of NaAlH4 and LiAlH4, in which the homogeneous doping of the transition metal catalyst is essential for the reversibility and fast kinetics. The reversible dehydrogenation and hydrogenation were clearly observed without a catalyst over a temperature range 250–340 °C under