In this paper, a series of Fe(1-x)Co(x) alloys (x = 0, 0.3, 0.5, 0.6, 0.7, 1) is in situ synthesized by a chemical reduction method and used as catalysts for generating hydrogen from aqueous solution of ammonia borane (NH(3)BH(3)) at room temperature. XRD and TEM characterizations reveal that these Fe(1-x)Co(x) nano-alloys are amorphous and ultrafine. The hydrogen generation measurements show that in situ synthesized Fe(1-x)Co(x) alloys exhibit excellent catalytic properties. The hydrogen generation rate of Fe(0.3)Co(0.7) alloy can reach to the maximum of 8945.5 ml min(-1) g(-1) at 293 K and the activation energy is only 16.30 kJ mol(-1). Furthermore, the hydrolysis of NH(3)BH(3) is completed within 1.8 min. The results are better than Fe, Co nano-particles and ex situ synthesized samples, which could be attributed to electron transfer from Fe to active Co sites, and improvement in the dispersion of the catalyst with Fe(2)O(3). (C) 2011 Elsevier B.V. All rights reserved.