Analysis of the stationary kinetic characteristics of an n-stage unbranched catalytic reaction (linear mechanism)

Conclusions We shall discuss what differences the complexity (n-stage character) brings into the kinetic characteristics of the simplest case examined by us: an unbranched cycle, linear with respect to the intermediate substances. In the range in which the reaction proceeds in the forward direction the temperature dependence for an exothermal complex reaction is identical to that for a simple reversible exothermal stage [1]. For a complex endothermal reaction are possible characteristics which are analogous to an elementary endothermal stage: a monotonic dependence, but also a novel property may appear: an extreme (no more than one) due to the strong hidden endothermal character. As was proved in the present study, the action of the partial pressures of the reactants is analogous to their effect on the rate of an elementary reaction: monotonic functions. The difference consists in that here in most cases a limiting rate exists as a result of, for example, the circumstance that the detailed mechanism embraces stages in which no gas phase participates.Consequently, we classified the typical stationary kinetic characteristics of an n-stage unbranched catalytic reaction with a mechanism linear with respect to the intermediate products. The results obtained in our study can be easily extended to other cases, too, when the kinetic equations are of the shape (1), for example, to some empirical equations.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 14, No. 4, pp. 529–533, July–August, 1978.