Hydrogen generation from Al/NaBH4 hydrolysis promoted by Li–NiCl2 additives

On-demand hydrogen generation from solid-state Al/NaBH4 hydrolysis activated by Li–NiCl2 additives are elaborated in the present paper. Hydrogen generation amount and rate can be regulated by changing Al/NaBH4 weight ratio, Li and NiCl2 amount, hydrolytic temperature, etc. The optimized Al−10 wt.% Li−15 wt.% NiCl2/NaBH4 mixture (weight ratio of 1:1) yields 1778 ml hydrogen/1 g mixture with 100% efficiency within 50 min at 323 K. The improved hydrolytic performance comes from the effect of Li–NiCl2 additives, which decrease aluminum particle size in the milling process and produce the catalytic promoter BNi2/Al(OH)3 in the hydrolytic process. Compared with the conventional reaction of Al and NaBH4 in water, there is an interaction of Al/NaBH4 hydrolysis which improves the hydrolytic kinetics of Al/NaBH4 via the catalytic effect of hydrolysis by-products Al(OH)3, BNi2, and NaBO2. The Al/NaBH4 mixture may be applied as a portable hydrogen generation material. Our experimental data lay a foundation for designing practical hydrogen generators.

► Al/NaBH4 mixture activated by Li and NiCl2 had good hydrolytic performance.
► It could be regulated by changing Al/NaBH4 weight ratio, Li and NiCl2 amount, etc.
► 1 g optimized mixture yielded 1778 ml hydrogen with 100% efficiency at 323 K.
► The improvement came from catalytic effect of BNi2/Al(OH)3 and interaction of Al/NaBH4 hydrolysis.