Hydrogen generation from the hydrolysis of aluminum lithium/sodium borohydride (referred to as AlLi/NaBH4) system activated by Co powder with different particle size and amount was evaluated in this paper. The designed aluminum-lithium-cobalt (referred to as Al-Li-Co/NaBH4) systems including Al-5 wt% Li-50 wt% nano Co, Al-7.5 wt% Li-25 wt% nano Co, Al-5 wt% Li-50 wt% micro Co, and Al-7.5 wt% Li-25 wt% micro Co had 100% hydrogen yield at 323 K. The hydrogen generation rates of these systems were regulated by Co species, Co amount, as well as consecutive runs of NaBH4 hydrolysis. The underlying activation mechanism, including the formation of Al0.94Co1.06 alloy and highly active and stable Co-based catalyst has been elaborated in this study. Experimental data present an inexpensive and highly efficient hydrogen source for portable fuel cell. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.