For hydrogen generation from an aqueous alkaline NaBH4 solution, Co-B catalyst was prepared by the chemical reduction method using NaBH4 as a reduction chemical. To design a hydrogen generator, hydrogen generation rate was measured using the Co-13 catalyst as a function of solution temperature, amount of catalyst loading, NaBH4 concentration, and NaOH (a base-stabilizer) concentration. Activation energy for the hydrogen generation reaction was measured to be 64.87 kJ mol(-1). Compared to Ru catalysts previously used, the low-cost Co-13 catalyst exhibited comparable activity for the hydrogen generation reaction. Using the hydrogen generation system employing the Co-13 catalyst, a 2 W polymer electrolyte membrane fuel cell (PEMFC) stack was operated and successfully powered a cellular phone. (c) 2005 Elsevier B.V. All rights reserved.