ZGB surface reaction model with high diffusion rates

The diffusionless ZGB (monomer–dimer) surface reaction model exhibits a discontinuous transition to a monomer‐poisoned state when the fraction of monomer adsorption attempts exceeds 0.525. It has been claimed that this transition shifts to 2/3 with introduction of rapid diffusion of the monomerspecies, or of both species. We show this is not the case, 2/3 representing the spinodal rather than the transition point. For equal diffusion rates of both species, we find that the transition only shifts to 0.5951±0.0002