Reversible hydrogen storage in the Ni-rich pseudo-binary Mg6Pd0.25Ni0.75 intermetallic compound: Reaction pathway, thermodynamic and kinetic properties

► Mg6.2Pd0.25Ni0.65 reversibly absorbs 5.6 wt.% H in a two plateau pressure PCI. ► The ternary phase depletes in Mg and Ni at low hydrogen pressure to form Mg2Ni. ► Reaction pathway of hydrogenation has been determined. ► Enthalpy of the high pressure plateau is less negative than the one of pure Mg. ► Low activation energy for desorption has been found for highly hydrided material.