Low-Temperature Reversible Hydrogen Storage Properties of LiBH4: A Synergetic Effect of Nanoconfinement and Nanocatalysis

LiBH4 has been loaded into a highly ordered mesoporous carbon scaffold containing dispersed NbF5 nanoparticles to investigate the possible synergetic effect of nanoconfinement and nanocatalysis on the reversible hydrogen storage performance of LiBH4. A careful study shows that the onset desorption temperature for nanoconfined LiBH4@MC-NbF5 system is reduced to 150 degrees C, 225 degrees C lower than that of the bulk LiBH4. The activation energy of hydrogen desorption is reduced from 189.4 kJ mol(-1) for bulk LiBH4 to 97.8 kJ mol(-1) for LiBH4@MC-NbF5 sample. Furthermore, rehydrogenation of LiBH4 is achieved under mild conditions (200 degrees C and 60 bar of H-2). These results are attributed to the active Nb-containing species (NbHx and NbB2) and the function of F anions as well as the nanosized particles of LiBH4 and high specific surface area of the MC scaffold. The combination of nanoconfinement and nanocatalysis may develop to become an important strategy within the nanotechnology for improving reversible hydrogen storage properties of various complex hydrides.