Periodic perturbation of the kinetics of heterogeneous catalytic reactions

Periodic forcing of reaction kinetics via, e.g., variation of reactant pressure(s), temperature or flow reversal is one of the useful tools employed in basic and applied studies of heterogeneous catalytic processes. In the case of conventional (stable) kinetics, this strategy is used to clarify the mechanisms of reactions and obtain data on reaction rate constants or to improve the reaction performance, e.g., to increase reaction rate and/or selectivity with respect to desired products. In experiments, that are focused on oscillatory catalytic reactions, periodic perturbations are employed to stabilize period-1 oscillations. This is easily achieved if the external and internal frequencies are equal. In a more general context, periodic perturbation of chemical reactions, that exhibit period-1 oscillations, may result in complex reaction behaviour, including period doubling and irregular kinetics provided that the external and internal frequencies do not coincide. We consider in this review both the relevant data available in the literature and the results of systematic calculations for a few generic models.