New synthesis route for ternary transition metal amides as well as ultrafast amide–hydride hydrogen storage materials

Abstract

K₂[Mn(NH₂)₄] and K₂[Zn(NH₂)₄] were successfully synthesized via a mechanochemical method. The mixture of K₂[Mn(NH₂)₄] and LiH showed excellent rehydrogenation properties. In fact, after dehydrogenation K₂[Mn(NH₂)₄]-8LiH fully rehydrogenates within 60 seconds at ca. 230 °C and 5 MPa of H₂. This is one of the fastest rehydrogenation rates in amide–hydride systems known to date. This work also shows a strategy for the synthesis of transition metal nitrides by decomposition of the mixtures of M[M′(NH₂)_n] (where M is an alkali or alkaline earth metal and M′ is a transition metal) and metal hydrides.