The model, proposed by Peskov et al. (Catal Today 105:223, 2005) to describe kinetic oscillations observed in the N2O + H-2 reaction on Ir(110), is used to illustrate the effect of periodic perturbation of the reactant pressures on oscillations. The attention is focused on the conversion of natural period-1 oscillations to period-1 oscillations with the imposed frequency. For this conversion, simultaneous perturbation of both reactant pressures is found to be much more efficient compared to perturbation of one of the pressures.