To reduce the greenhouse effect and as a fuel alternatives hydrogen is used as a secure and clean energy. But there are some challenges in the storage of hydrogen energy, the present accurate dynamics of adsorption and release of hydrogen. We report the adsorption and desorption of hydrogen atoms (up to eight) on the ZrAlm (m = 3 to 7) clusters using density functional theory within B3PW91/LANL2DZ basis sets in the GAUSSIAN 09 package. Adsorption energy for per hydrogen atom in all clusters is found in the range of -2.5 eV to -3.3 eV, which shows the chemisorption of hydrogen on the ZrAlm clusters. Change in the DOS with number of hydrogen is attributed to the charge transfer between the ZrAlm clusters and hydrogen atoms. Highest HOMO-LUMO gap of 3.055 eV is found for the ZrAl3H7 cluster which indicates that the ZrAl3H7 cluster is chemically more stable. Work function values for hydrogen doped clusters are in the range of 3.5 eV-4.4 eV which suggests the low optical absorption in considered clusters. The calculated enthalpy difference further confirms the chemisorption of hydrogen on ZrAlm clusters ZrAl3Hn and ZrAl7Hn (for n = 1 to 5 and 7) are more exothermic than other considered clusters. Desorption energies per hydrogen for these clusters are found lower than the some of the best catalytic clusters Pd-13 and Pt-13 indicating more catalytic active nature. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.