In this work we study a model of a catalytic reaction among three monomers in order to understand the kinetics of the selective catalytic reduction of NO by ammonia (4NO + 4NH3 + O2 -> 4N2 + 6H2O). Our model takes into account the formation of the intermediate species in the global scheme of the reaction. Using the Monte Carlo method we simulated the model on a square lattice and determined its phase diagram.
