A new model is developed to analyze oxygen interference in hydrogen storage materials. It is based on the competitive adsorption isotherm between the two gases, with the parameters fitted from molecular dynamic simulations. The model is applied to a system consisting of graphene sheets separated by different distances. For a gas-phase mixture of hydrogen (99.9%) and oxygen (0.1%) in interaction with porous graphite of 6.5 angstrom (optimum size) it can be observed that after 50 cycles of charging/discharging the blocking of active sites of the material by oxygen is similar to 10%, due to progressive pollution of the system by oxygen. The model presented here may easily be extended to other systems of interest, involving other blocking species or adsorbent materials. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.