Effect of the Temperature and Pressure on Hydrogen Generation from Sodium Borohydride by Thermolysis Using a Catalyst

Sodium borohydride (NaBH4) has a theoretical gravimetric H2 storage of 10.6 wt %, which has long been considered a viable hydrogen-storage material. Considering the facile solution method, a series of composite materials (catalyst/NaBH4) were synthesized and studied for hydrogen generation via thermolysis in a high-pressure reactor by changing the system pressures (1, 5, 10, and 20 bar). X-ray diffraction (XRD), thermogravimetry differential thermal analysis (TG–DTA), field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR) were used to characterize the materials. The composite material 30CaCl2/NaBH4 (1.41 wt %) generated more hydrogen than pure NaBH4 (0.11 wt %). System pressure also plays a crucial role in changing the material properties and hydrogen generation. The production of hydrogen declined as the system pressure rose from 1 to 20 bar. The optimal system pressure of composite material thermolysis is suggested to be 1 bar at 100 °C.