Catalysis and hydrolysis properties of perovskite hydride NaMgH3

•The formation of NaMgH3 in the NaH doped MgH2 improves the hydrogen sorption kinetics of MgH2.•The catalytic role of NaMgH3 is related with its perovskite structure.•The NaMgH3 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 MgH2, which is related to the formation of ternary hydride NaMgH3 with specific perovskite structure. The MgH2–10%NaH mixture exhibits better hydriding and dehydriding kinetics than the MgH2–10%LiH mixture, in which the LiMgH3 with perovskite structure could not be formed. The catalytic role of NaMgH3 is attributed to fast hydrogen mobility in the perovskite structure, which provides fast hydrogen diffusion pathways for the hydriding and dehydriding of MgH2. The NaMgH3 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.