We performed Monte Carlo simulations to study catalytic surface reaction of the type
We chose two different types of catalytic surfaces in our studies: one represented by a square lattice (coordination number four) and the other represented by a triangular lattice (coordination number six). The whole process can be described by a single parameter, which is taken as the relative adsorption of BA molecules. In our model, we always need two nearest neighbor sites to the adsorption of both molecules. After deposition, the A 2 molecules dissociate occupying two nearest neighbor sites, while the BA molecules stay bound. The reaction occurs only when a free A atom is nearest neighbor of a B atom of the BA molecule. In spite of each reaction freeing three empty sites on the lattice, this model does not exhibit any reactive window for both lattices. Only when we introduce processes like the diffusion of BA molecules or free A atoms, or desorption of BA molecules, the catalytic surface can become active for some values of deposition rate y BA . As to be expected, the reactivity over the triangular lattice is higher than that observed on the square lattice.