A high-performance hydrogen generation system based on transition metal-catalyzed dissociation and hydrolysis of ammonia-borane complex (NH3BH3) at room temperature has been achieved. NH3BH3 dissolves in water to form a solution stable in the absence of air. The addition of a catalytic amount of suitable metal catalysts such as Pt, Rh, and Pd into the solutions with various concentrations leads to rigorous release of hydrogen gas with an H-2 to NH3BH3 ratio up to 3.0, corresponding to 8.9 wt.% of the starting materials NH3BH3 and H2O. The Pt catalysts are the most active and no significant deactivation was observed for the recycled catalysts. This new system possesses high potential to find its application to portable fuel cells. (c) 2005 Elsevier B.V. All rights reserved.