Microkinetic model is a very powerful technique for understanding catalytic processes. In the present study, this model was implemented in order to investigate CO2 reforming of methane (DRM) over Ni/gamma-Al2O3 at atmospheric pressure and temperatures between 450 degrees C and 650 degrees C. The effect of operating conditions such as temperature on the surface coverages and the elementary surface reactions have been investigated. From the obtained results, it is observed that the main oxidizer produced in our case is OH* and not O* which comes from the oxidation of hydrogen on the surface of catalyst. Rising temperature favours the dissociation of CH4*and CO2*. Consequently, it's responsible for the formation of H*, H2O* and C*, while the latter causes the catalytic deactivation. It was found that this deactivation process is significant at higher temperatures. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.