Improved Dehydrogenation Properties of LiBH 4 Using Catalytic Nickel‐ and Cobalt‐based Mesoporous Oxide Nanorods

Lithium borohydride (LiBH 4 ) with a theoretical hydrogen storage capacity of 18.5 wt % has attracted intense interest as a high‐density hydrogen storage material. However, high dehydrogenation temperatures and limited kinetics restrict its practical applications. In this study, mesoporous nickel‐ and cobalt‐based oxide nanorods (NiCo 2 O 4 , Co 3 O 4 and NiO) were synthesized in a controlled manner by using a hydrothermal method and then mixed with LiBH 4 by ball milling. It is found that the dehydrogenation properties of LiBH 4 are remarkably enhanced by doping the as‐synthesized metal oxide nanorods. When the mass ratio of LiBH 4 and oxides is 1:1, the NiCo 2 O 4 nanorods display the best catalytic performance owing to the mesoporous rod‐like structure and synergistic effect of nickel and cobalt active species. The initial hydrogen desorption temperature of the LiBH 4 ‐NiCo 2 O 4 composite decreases to 80 °C, which is 220 °C lower than that of pure LiBH 4 , and 16.1 wt % H 2 is released at 500 °C for the LiBH 4 ‐NiCo 2 O 4 composite. Meanwhile, the composite also exhibits superior dehydrogenation kinetics, which liberates 5.7 wt % H 2 within 60 s and a total of 12 wt % H 2 after 5 h at 400 °C. In comparison, pure LiBH 4 releases only 5.3 wt % H 2 under the same conditions.