It has been found that the reaction products between TiCl3 and Li3AlH6 by mechanical milling consist of LiCl and TiAl3 together with TiH(2)Thermodynamic calculation also predicts that TiAl3 becomes dominant over TiH2 with increasing temperature. Based on this, ultra-fine TiAl3 powder having the primary particle size of about 100 nm has been mechanochemically synthesized from a mixture of TiC1(3), AlC1(3) and Mg. The addition of this TiAl3 powder into Li3AlH6 clearly shows a good catalytic effect on the thermal decomposition of Li3AlH6 as expected. The use of fine TiAl3 catalyst is certainly more favorable than TiC1(3) in terms of hydrogen storage capacity as it does not produce irreversible chloride byproduct in alanates. (c) 2006 Elsevier B.V. All rights reserved.