Simulation of kinetic oscillations in the CO+O2/Pt reaction on the nm scale

Using the Monte Carlo technique, we simulate kinetic oscillations in CO oxidation occurring on nm-sized supported Pt particles via the conventional Langmuir–Hinshelwood mechanism and surface oxide formation and removal. Incorporating cooperative effects into the oxide growth mode, we demonstrate that the oscillations may be accompanied by remarkable segregation between oxide and CO. During oscillations, the maximum CO coverage may be appreciably smaller that that at saturation. These findings are in line with recent transient Fourier transform infrared spectroscopy measurements (Fanson, P.T., Delgass, W.N., Lauterbach, I., J. Catal. 204 (2001) 35) indicating that during oscillations on Pt/SiO2 the CO coverage is relatively low and the shift of the stretching frequency of linearly bonded CO is nearly negligible.