How do you expect the metallic hydrides to be useful for hydrogen storage? Explain.

In metallic hydrides, hydrogen is absorbed as H^- atoms. Due to the inclusion of H atoms, the metal lattice distorts and expands and thus becomes less stable. On heating, metallic hydride decomposes to give hydrogen and very finely divided metal. The liberated hydrogen gas can be used as a fuel. Thus transition metals (eg Pd, Pt) or their alloys can be used as storage media and transport hydrogen to be used as a fuel. This is called hydrogen economy.