Enhanced dehydrogenation of hydrazine bisborane for hydrogen storage

NiCl₂ and CoCl₂ were adopted to enhance the dehydrogenation of hydrazine bisborane (HBB), respectively, of which NiCl₂ showed better performance. By adding 2.0 mol. % NiCl₂, the dehydrogenation property of HBB was significantly improved, for example, the impurity of NH₃ during the dehydrogenation of HBB was totally suppressed with more than 13.0 wt. % of pure hydrogen evolved. By Kissinger method, the apparent activation energies of the first step for HBB and Ni-doped HBB were calculated to be 143.2 and 60.7 kJ mol⁻¹, respectively. DSC result showed that the addition of NiCl₂ did not change the enthalpy change of HBB dehydrogenation. Based on theoretical analysis and literature review, the improved dehydrogenation property of HBB was potentially ascribed to the solid state interaction of Ni²⁺ with the electronegative N in the NH₂ group of HBB.