In this work the hydrogen storage behaviors of multi walled carbon nanotubes (MWNTs) loaded by crystalline platinum (Pt) particles were studied The microstructure of the Pt/MWNTs was characterized by X ray diffraction and transmission electron microscopy The pore structure and total pore volumes of the Pt/MWNTs were analyzed by N(2)/77 K adsorption isotherms The hydrogen storage capacity of the Pt/MWNTs was evaluated at 298 K and 100 bar From the experimental results it was found that Pt particles were homogeneously distributed on the MWNT surfaces The amount of hydrogen storage capacity increased in proportion to the Pt content with Pt 5/MWNTs exhibiting the largest hydrogen storage capacity The superior amount of hydrogen storage was linked to an increase in the number of active sites and the optimum controlled micropore volume for hydrogen adsorption due to the well dispersed Pt particles Therefore it can be concluded that Pt particles play an important role in hydrogen storage characteristics due to the hydrogen spillover effect Crown Copyright (C) 2010 Published by Elsevier Ltd on behalf of Professor T Nejat Veziroglu All rights reserved