Co-based catalyst can significantly improve the dehydrogenation kinetics of the eutectic composite of LiBH4-Mg(BH4)(2) (1/1 M ratio). The onset hydrogen desorption temperature of the composite is at about 155 degrees C, which is ca. 245, 110 or 27 degrees C lower than that of LiBH4, Mg(BH4)(2) or pristine LiBH4-Mg(BH4)(2), respectively. Upon holding the samples at 270 degrees C, the Co catalyzed composite can release hydrogen at a rate 1.6 times faster than that of the pristine one. Electron Paramagnetic Resonance (EPR) characterization evidenced that Co was in a reduced state of Co+ which may serve as the functional species in catalyzing the dehydrogenation of the composite. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.