A ternary Mg2FeH6 hydride was synthesized applying the processing route described in detail in [4]. Subsequently, a nanocomposite of 2Mg + Fe was produced through a thermal decomposition of Mg2FeH6 precursor. Microstructural studies by SEM, STEM, EDS, EELS and XRD show a microstructure consisting of nanocrystalline nearly spherical Fe particles with an average diameter of 20-30 nm uniformly distributed in the nanocrystalline Mg matrix exhibiting the grain size on the order of 5-10 nm. The 2Mg + Fe nanocomposite was subsequently hydrogenated at 30 degrees C under 4 MPa of hydrogen pressure. After 10 h about 1.1 mass% of hydrogen has been absorbed but the pertinent desorption curve shows that the hydrogenation process is not saturated yet. Temperature programmed desorption (TPD) of hydrogenated 2 Mg + Fe sample shows an asymmetrical desorption peak with a tail extending from similar to 130 to 200 degrees C, then sharp increase in the peak height and eventually a sudden drop around a maximum at similar to 250 degrees C. This asymmetrical shape strongly suggests that a large population of nanocrystalline grains being in an intimate contact with the nanocrystalline particles of Fe which, most likely, act as a catalyst, is able to desorb hydrogen at very low temperatures from similar to 130-250 degrees C under helium flow used in a TPD test. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.