Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

OP-I-9This work is a continuation of [2], which was devoted to the development of a lowdimensionalkinetic model of CO oxidation on a metallic catalyst surface and the theoreticalstudy of arising nonlinear phenomena and relaxation oscillations of the reaction rate. In thepaper [2], the conventional Langmuir-Hinshelwood mechanism of catalytic CO oxidation wasconsidered under assumption of the possibility of a metal surface modification in the courseof catalytic reaction due to the oxygen penetration into subsurface layers.The rate of changing the third coordinate z is smaller then the rates of the other reactionstages, and the dynamic properties of the whole system are inherently determined by thestructure of limit sets of the one-parameter family of submodels with two variables x, y andparameter z. These submodels have a hysteresis of steady states and two maximal families ofperiodic solutions at some K i values (i = 1, -1, 2, 3). For each family, the periodic solutions atone of the boundaries degenerate into the homoclinic orbit that is a saddle-loop separatrix. Inthis case the periodic solutions are highly parametric sensitive. Moreover, there are twoscenarios of the chaotic dynamics birth in the model at some values of K 4 and K 5 , namely: bymeans of a cascade of period-doubling bifurcations and owing to the mixed-mode oscillations(see Fig. 1).Figure 1. The examples of a strange attractor as a result of the cascade of period-doubling bifurcations (left part)and chaotic oscillations as a result of the development of mixed-mode oscillations (right part)References:1. G.A. Chumakov, M.G. Slinko. Dokl. Akad. Nauk SSSR, 1982, 266, 5, 1194-1198.2. E. Ivanova, N. Chumakova, G. Chumakov, A. Boronin. Chem. Eng. J. 2005, 107, 191-198.43