A Monte Carlo Simulation of a Monomer Dimer CO-O₂ Catalytic Reaction on the Surface and Subsurface of a Face-centered Cubic Lattice

The presence of oxygen in the subsurface in monomer-dimer reactions (CO-O₂ and NO−CO) is observed experimentally. The effect of subsurface oxygen on a CO-O₂ catalytic reaction on a face-centered cubic (FCC) lattice is studied using Monte Carlo simulation. The effect of adding subsurface neighbours on the phase diagram is also extensively explored. It is observed that the subsurface oxygen totally eliminates the typical second order phase transition. It is also shown that the introduction of the diffusion of O atoms and the subsurface of the FCC lattice shifts the single transition point towards the stoichiometric ratio.