Controllable hydrogen generation and hydrolysis mechanism of AlLi/NaBH4 system activated by CoCl2 solution

Hydrogen generation performance of solid-state AlLi/NaBH4 mixture activated by CoCl2 solution was evaluated in the present work. Hydrogen generation performance can be regulated by AlLi/NaBH4 weight ratio, Li content, CoCl2 concentration, and hydrolysis temperature, among others. 1 g Al-20 wt% Li/NaBH4 mixture (weight ratio, 1:1) yields 1674 mL hydrogen with 89% efficiency in 2.5 wt%CoCl2 solution at 303 K. The relative hydrolysis mechanism and optimized composition design are reported and discussed through the analysis of XRD, SEM, IR, and particle size distribution. The hydrolysis byproducts LiOH and Co2B/Al(OH)3 are the major factors to improve the hydrolysis performance of an AlLi/NaBH4 mixture. Our experimental data show that the new method of hydrogen generation from AlLi/NaBH4 hydrolysis activated by CoCl2 solution may supply free CO2, portable hydrogen for proton exchange membrane fuel cell.

► Hydrogen generation from AlLi/NaBH4/CoCl2 solution could be applied for fuel cells.
► Al-20 wt%Li/NaBH4 (weight ratio 1:1) yielded 1674 mL g−1 hydrogen with 89% efficiency.
► The improved performance came from the dual catalytic effect of Co2B/LiOH/Al(OH)3.
► The relative hydrolysis mechanism was reported and discussed.