Hydrogen generation from coupling reactions of sodium borohydride and aluminum powder with aqueous solution of cobalt chloride

On-demand hydrogen generation from the hydrolysis reactions of chemical hydrides has gained ever-increasing attention as a promising approach for providing mobile/portable hydrogen sources. In this paper, we report a new chemical hydrogen storage system that is composed of sodium borohydride (NaBH4)/aluminum (Al)/sodium hydroxide (NaOH) solid powder mixture and aqueous solution of cobalt chloride (CoCl2). Hydrogen generation can be readily controlled by regulating the contact of the aqueous solution with the solid powder mixture. In comparison with the conventional NaBH4/H2O or Al/H2O systems, the newly developed dual-solid-fuel system exhibits distinct advantages in hydrogen storage density, hydrogen generation rate and fuel conversion. Additionally, the dual-solid-fuel system shows satisfactory transient response. The factors influencing the hydrogen generation performance of the system were studied. The reaction by-products were characterized using powder X-ray diffraction and Fourier transform infrared spectroscopy techniques. Our study demonstrated a high-performance dual-solid-fuel hydrogen generation system, and may lay a foundation for developing practical hydrogen generators for mobile/portable applications.