Phase diagrams of the YK surface-reaction model on 2D lattices with exchange diffusion

In this work, we investigate the phase diagrams of the Yaldram and Khan catalytic surface model on square and hexagonal lattices when exchange diffusion is allowed for carbon monoxide (CO) and nitrogen (N) atoms. To reach our goal, we carried out extensive steady-state Monte Carlo simulations, for both lattices, in order to obtain a framework of the steady reactive state of the model for different values of the nitric oxide dissociation rate, rNO. The results show the emergence of steady reactive state for certain values of rNO and of exchange diffusion rate x when the simulations take place on square lattice. Our findings on the hexagonal lattice also show that the diffusion of these species favors the appearance of the active phase for values of rNO lower than that found for the standard model (without exchange diffusion). In addition, we observed that the system possesses a continuous phase transition and a discontinuous one separating the active phase from absorbing states for both lattices, except for rNO=1 in which the continuous phase transition is destroyed and a steady reactive state emerges from the beginning since very small values of x.