Enhanced Low-Temperature Hydrogen Storage in Nanoporous Ni-Based Alloy Supported LiBH₄

To reveal the synergistic effect of nanoconfinement and metallic catalysis on the hydrogen storage properties of LiBH₄, the nanoporous Ni-based alloy (np-Ni) was prepared herein by dealloying of the Mn₇₀Ni₃₀ alloy in (NH₄)₂SO₄ solution, and then LiBH₄ was loaded into np-Ni to construct the LiBH₄/np-Ni hydrogen storage system using wet impregnation. It was found that dehydrogenation of the LiBH₄/np-Ni (1:5) system starts at around 70°C and ends before 400°C, with ~11.9 wt.% of hydrogen desorbed. The apparent dehydrogenation activation energy for the LiBH₄/np-Ni (1:5) system was remarkable decreased to about 11.4 kJ/mol. After rehydrogenation at 450°C under 8 MPa hydrogen pressure, ~8.2 wt.% of hydrogen can be released from about 60°C upon second dehydrogenation. These obtained results would provide an efficient strategy for improving the hydrogen storage properties of other metal borohydrides.