The synthesis of hydrazine borane and derivatives and its utilization in the catalytic hydrogen production

The reliable and efficient storage of hydrogen has been a key enabling technology for the advancement of a hydrogen-based energy infrastructure. Recently, several studies have been conducted in the field of hydrogen storage materials. However, the most important application problem regarding boron compounds, which are considered as hydrogen storage materials in the future, is the rapid and controlled production of hydrogen required for fuel cells. Efficient and reversible hydrogen release can be achieved from the boron based materials via catalytic and non-catalytic dehydrogenation. Particularly, hydrazine borane (N2H4BH3) and hydrazine bisborane (N2H4(BH3)2) have been taken into account as chemical hydrogen storage materials due to their high hydrogen contents (15.4% and 16.8%). In this study, the non-catalytic and catalytic synthesis of hydrazine borane and bisborane was performed (TiO2, CuO, RuO2 and Ru/TiO2, Y2O3, ZnO and AlCl3 catalysts). As a result of catalytic synthesis (TiO2 catalyst) conducted by changing the temperature, reactant mole ratio, pH and reaction time, hydrazine borane and hydrazine bisborane were obtained with 95% and 90% yield, respectively. The products were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), 11B Nuclear Magnetic Resonance Spectroscopy (11B NMR) and 1H Nuclear Magnetic Resonance Spectroscopy (1H NMR). In addition, hydrogen production was carried out by catalytic dehydrogenation of as-synthesized hydrazine borane and bisborane. Binary and ternary catalysts (Pd-Ni/B and Rh-Ni/Zr-B) were prepared by impregnation method. Their catalytic properties and performance were assessed (SEM, XPS and XRD analyses) for the catalytic dehydrogenation. Accordingly, the hydrolysis of hydrazine borane and bisborane generated 2.8 moles and 4.5 moles of (H2+N2) gas at 60 °C with Rh-Ni/Zr-B catalyst, whereas 3.58 moles and 5.4 moles of (H2+N2) gas were produced in the presence of Pd-Ni/B catalyst, respectively.