Porous (Cu,Ni)/Cu2O heterostructure-induced destabilization of LiBH4 for reversible hydrogen storage

LiBH 4 , a solid-state hydrogen storage material with ultra-high theoretical hydrogen capacity, is seriously hindered for the practical applications by its high thermodynamic stability and slow hydrogen desorption kinetics. Herein, the dehydrogenation properties of LiBH 4 are remarkably improved by confinement in the porous (Cu,Ni)/Cu 2 O heterostructure (np-(Cu,Ni)/Cu 2 O), which was achieved using a novel two-step method containing dealloying of Mg–Cu–Ni precursor alloy to form the porous (Cu,Ni) solid solution, followed by micro-oxidation under air conditions. Hydrogen release from the constructed LiBH 4 @np-(Cu,Ni)/Cu 2 O (1:2, mass ratio) system begins at approximately 80°C and ends before 380°C, with 12.5wt% of hydrogen desorbed. Moreover, the apparent dehydrogenation activation energy has been reduced to 44.2 kJ/mol. After rehydrogenation at 400°C under 8 MPa hydrogen pressure, the LiBH 4 @np-(Cu,Ni)/Cu 2 O (1:2, mass ratio) system can release 3.6wt% of hydrogen during the second dehydrogenation process. These findings show that the synergistic effect of confinement and heterostructure catalysis provided by the porous metal derivatives can greatly enhance the hydrogen storage properties of LiBH 4 .