Summary: The paper contains a detailed bifurcational analysis of stationary and non-stationary time-periodic solutions in a certain mathematical model of the NO+CO reaction on (100) plane of platinum monocrystal in a continuously stirred tank reactor. The diagrams of nonequilibrium states of the reactional system are constructed in the plane of \(P_{CO}\) and \(P_{NO}\) partial pressures and in temperature – \(P_{CO}\) pressure plane. The influence of the reactor pumping rate on the structure of nonequilibrium state diagrams was studied. Hysteresis phenomena accompanied by self-oscillations of the reaction rate were discovered.