Using Density Functional Theory (DFT), the desorption energies of Hydrogen in Aluminum, and Boron nanoparticles (NPs) is calculated. The type of NPs studied here, were MnHm with M = Al or B, n varying from 2 up to 20 and m/n between 0 and 3. NPs combining the two atoms (Aln-xBxH3n) were also examined. These types of clusters combine the low weight of B with the low desorption energies of Al. For each NP, several different geometries were studied in order to find the one with the lowest energy. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.