Improved Dehydrogenation Performance of Li-B-N-H by Doped NiO

Abstract

In order to improve the dehydrogenation properties of the Li-B-N-H system, a flower-like NiO was successfully synthesized using the hydrothermal method. The effect of the NiO on the dehydrogenation properties of the LiBH4-2LiNH2 system was studied. The results showed that the dehydrogenation properties of the LiBH4-2LiMH2 system were significantly enhanced by doping with NiO. The composite doped with 5 wt. % NiO exhibited optimal hydrogen storage properties. It released about 10.5 wt. % hydrogen below 300 °C, and the onset dehydrogenation temperature was only 90 °C, 110 °C lower than that of LiBH4-2LiNH2. The isothermal dehydrogenation experiment indicated that the LiBH4-2LiNH2-5 wt. % NiO composite released 8.8 wt. % hydrogen within 15 min at 150 °C. Structural analysis revealed that the as-prepared NiO was reduced to metallic Ni, which worked as an active catalytic species in the remainder of the dehydrogenation process. The Mass Spectrometer (MS) analyses showed that the doped NiO inhibited the content of NH3 released in the process of the dehydrogenation of LiBH4-2LiNH2-NiO.