In the present work, we have investigated the hydrogenation properties of La0.5R0.5Ni4.8Al0.1Li0.1 (R = Ce, Pr or Nd) alloys under the hydrogen pressure ranging from 0.02 to S MPa. The pressure-composition (p-c) isotherms have been measured at four temperatures (293, 313, 333 and 353 K) in order to evaluate hydrogen absorption/desorption abilities of the alloys. For the investigated systems, the enthalpy and entropy of the dehydrogenation process have been calculated using van't Hoff plots. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.