Synergistic hydrogen generation from AlLi alloy and solid-state NaBH4 activated by CoCl2 in water for portable fuel cell

Solid-state AlLi/NaBH4 mixture activated by CoCl2 salt is fabricated for hydrogen generation via a milling process, providing uniform dispersion of AlLi alloy and CoCl2 salt among pulverized NaBH4 particles in order to improve NaBH4 hydrolysis through the contact of NaBH4 with active catalytic sites. The active catalytic sites come from Co2B loaded in Al(OH)3 (Bayerite) or LiAl2(OH)7 hydrate, generated from the reaction of CoCl2, AlLi alloy, and NaBH4 in water. The results show that the gravimetric hydrogen storage capacity is as high as 6.4 wt.% and an efficiency of above 90% in 30-min hydrolysis at 323 K could be achieved using the limited amount of water. The hydrogen generation amount and rate could be regulated by changing the composition, mixing style, mixture/water weight ratio, and hydrolysis temperature. The relative mechanism is explored.

► Solid-state AlLi/NaBH4 mixture were activated by CoCl2 salt for hydrogen generation. ► The active catalytic sites come from Co2B loaded in Al(OH)3 (Bayerite) or LiAl2(OH)7 hydrate at 323 K. ► The optimized mixture showed 6.4 wt.% H2 with an efficiency above 90%. ► The hydrogen generation amount and rate could be regulated by changing the composition, etc.