Hydrogen generation by hydrolysis of alkaline NaBH_4 solution on Co-Mo-Pd-B amorphous catalyst with efficient catalytic properties

摘要

Mo-modified Co-Pd-B (Co-Mo-Pd-B) and Pd-modified Co-B (Co-Pd-B) catalyst powders are synthesized by chemical reduction of cobalt and molybdenum salt at ambient conditions. The resulting catalyst powders are characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), X-photoelectron spectroscopy (XPS) and BET surface area measurement. The study on the catalytic efficiency of amorphous Co-Mo-Pd-B catalyst powders is performed in hydrogen generation by hydrolysis of alkaline sodium borohydride (NaBH_4). The Co-Mo-Pd-B powders show the highest hydrogen generation rate as compared to Co-B, Co-Mo-B, and Co-Pd-B catalyst powders. Kinetic studies on the hydrolysis reaction of NaBH_4 with Co-Mo-Pd-B catalyst reveal that the concentrations of both NaBH_4 and NaOH have essentially no evident effects on hydrogen generation rate. The promoting effect of Mo in Co-Mo-Pd-B catalyst results in lower activation energy for hydrogen production, which is 36.36 kJ mol~(-1) compared to 64.87 kJ mol~(-1) obtained with pure Co-B powder.