Insights into the effect of growth on the Ziff–Gulari–Barshad model and the film properties

Abstract

We perform kinetic Monte Carlo computations with a modified Ziff-Gulari-Barshad (ZGB) model which considers the growth of a film. We show that the growth of the film significantly affects the conclusions that can be drawn from the ZGB model, even if the main mechanism, the surface reaction, remains the same. We compare the results of the growth model to the original ZGB and the phase transitions disappears; they are replaced by a smooth transition from 0 to full coverage. The latter observations qualitatively agree with experimental measurements for the CO2 formation. However, in the growth model the surface is always poisoned to a particular coverage values due to the local height differences of the lattice sites. Finally, a potential mechanism based only on surface phenomena which can lead to the decrement of the growth rate even if the amount of the precursor increases is explored.