Catalysis and hydrolysis properties of perovskite hydride NaMgH3

Abstract

• The formation of NaMgH 3 in the NaH doped MgH 2 improves the hydrogen sorption kinetics of MgH 2 . • The catalytic role of NaMgH 3 is related with its perovskite structure. • The NaMgH 3 shows fast hydrolysis reaction kinetics without any passivation. The addition of NaH by ball milling is shown to greatly improve the hydrogen storage properties and the hydrolysis properties of MgH 2 , which is related to the formation of ternary hydride NaMgH 3 with specific perovskite structure. The MgH 2 –10%NaH mixture exhibits better hydriding and dehydriding kinetics than the MgH 2 –10%LiH mixture, in which the LiMgH 3 with perovskite structure could not be formed. The catalytic role of NaMgH 3 is attributed to fast hydrogen mobility in the perovskite structure, which provides fast hydrogen diffusion pathways for the hydriding and dehydriding of MgH 2 . The NaMgH 3 also shows fast hydrolysis reaction kinetics without any passivation. Our work shows that such perovskite-type hydride demonstrates great potential as efficient catalysts for the high-capacity hydrides for whether reversible or irreversible hydrogen storage.