Theoretical analysis of the reactor performance under unsteady-state conditions was carried out. The reactions are described by two kinetic models, which involve the participation in catalytic reaction of two types of active sites. The kinetic model I assumes the blocking of one of the active sites by a reactant, and the kinetic model H suggests a transformation of active sites of one type into another under the influence of the reaction temperature. The unsteady-state conditions on the catalyst surface are supposed to be created (i) by forced oscillations of temperature and concentration in the reactor inlet (periodic operation of reactor) and (ii) by catalyst circulation between two reactors in a dual-reactor system (spatial regulation). ne influence of various parameters like concentration of reactant, cycle split, length of period of forced oscillations, temperatures and the ratio of catalyst volumes in the dual-reactor was investigated with respect to the yield of the desired product. It is shown that for both cases of unsteady-state conditions (periodic reactor operation as well as in a dual-reactor system), a mean reaction rate predicted by the kinetic model I was up to two times higher than the steady-state value. The kinetic model II shows a 20 % increase of the selectivity towards the desired product.