Transient ordered states in a model reaction on a surface with active sites
A model for the monomer-monomer surface reaction of the type A + B --> AB, with diffusion of A and B monomers on a surface and reaction only on active sites randomly distributed on the surface, has been proposed and studied. For a critical point where both adsorption probabilities are the same, a seemingly reactive steady state transforms itself into a poisoned state. In this transient state, the production of AB molecules, in relation to the density of active sites, is considered and an inert-reactive irreversible phase transition is observed. The critical values of the density of active sites, where the irreversible phase transition occurs, is obtained in the limit L --> infinity by means of a finite-size scaling analysis. The critical exponents that dominate the correlation length of clusters, as well as the production of AB molecules at criticality, axe determined.
irreversible phase transition monte carlo simulation models of surface chemical reactions