Abstract
A porous MgH2/C composite can be synthesized through decomposition of an organo-magnesium precursor under hydrogen pressure. XRD patterns of the porous MgH2/C composite exhibit a pure MgH2 phase with a tetragonal structure. The morphology of the resulted samples is significantly dependent on the synthesis temperature and hydrogen pressure. The samples exhibit a rod-like structure and composed of nano-crystallites of MgH2 with a size of less than 5 nm. TPD spectra of a sample synthesized at 220 degrees C for 4 h show a remarkable decrease of the onset hydrogen release temperature. Further, this sample also exhibits fast hydrogen adsorption kinetics adsorbing 6 wt % of hydrogen in 3 mm at 250 degrees C. The same amount of hydrogen is adsorbed in 11 min at 200 degrees C and 40 min at 150 degrees C, respectively. N-2 physisorption measurements of this sample indicate meso-porosity with a BET surface area of 40.9 m(2) g(-1) and an average pore diameter of 20 nm. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.