A disordered mesoporous hollow carbon spheres were decorated with Pd nanoparticles and their H-2 sorption performance was examined at 40 degrees C and up to 45 bar. It was found that Pd supported carbon spheres exhibited enhanced H-2 uptake capacity in comparison to the pristine material, despite the fact that their surface area and porosity decreased after Pd incorporation. The effect of the amount of Pd loading on the hydrogen storage abilities of the samples was studied. The results revealed that the H-2 uptake increases with increasing of Pd content and particle size. It is essential that for 3-Pd@C_24 sample (as the one with the highest H-2 uptake) the morphology and uptake capacity have been not changed during multiple adsorption/desorption cycles. The hydrogen storage mechanism in the investigated samples was also proposed. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.