Kinetic instabilities in heterogeneously catalyzed reactions. Pt. 2, Oscillatory instabilities with Langmuir type reactions

Abstract

An analysis of the kinetic model studied in Part I of this contribution gave no indication for the occurrance of periodic solutions. However if an additional slow chemisorption ("buffer") step is added to the model, relaxation oscillations can develop in regions where the original model exhibited multiple solutions. The behaviour of the extended model is analysed via the singular perturbation approach and by simulation. It is shown that a broad variety of slow chemisorption steps can serve as buffer with the restriction that the buffer step should not, or at least only slightly, contribute to the surface reaction.