THEORETICAL INQUIRY INTO THE MICROSCOPIC ORIGINS OF THE OSCILLATORY CO OXIDATION REACTION ON PT(100)

An improved model is presented which simulates temporal behavior in th e CO + O-2 reaction on the Pt{100} surface. The model is based on an e xperimentally determined strongly nonlinear power law for (1 x 1)-CO i sland, growth rate from the hexagonal (hex) phase with an apparent rea ction order of about 4 in the local CO coverage on the hex phase. The power law describes the phase transition from the hexagonal phase of t he reconstructed Pt surface to the (1 x 1) phase. Rate parameters from recent adsorption and desorption experiments are used in the modeling . The variations of all adsorbate coverages, the reaction rates, and t he surface phase are monitored to provide extensive information about the reaction. New insight into the mechanisms driving the experimental ly observed oscillations is gained, and an interpretation of the actua l dynamics of the underlying surface processes is also given.