Periodic perturbations of the oscillatory CO oxidation on Pt(110): Model calculations

The periodically perturbed oscillations in the isothermal CO oxidation on a Pt(110) surface at low pressure were modeled using the recently developed reconstruction model of kinetic oscillations, in which the usual Langmuir-Hinshelwood mechanism is coupled with the CO-driven 1×2⇄1×1 phase transition of the surface. The experimental findings (entrainment bands, quasiperiodicity, critical slowing down) could be well reproduced with this model. The calculations revealed a complicated bifurcation fine structure of the Arnol'd tongues. While the skeleton structure turned out to be the same as in other studies, some additional features were found, and several details (mainly in the p/2 tongues) were different from forced systems examined previously. A co-dimension-3 bifurcation (in which a second-order resonance coincides with a degenerate period doubling) is discussed in this context.