A Mechanistic Study of Oscillations and Bistability in the Briggs-Rauscher Reaction

Abstract

A ten-step mechanism has been developed for the Briggs-Rauscher system which contains iodate, hydrogen peroxide, malonic acid, and manganese(II) in acidic solution. The model is qualitatively identical with, though it differs quantitatively from, that proposed independently by Noyes and Furrow. It also bears strong similarities to the mechanistic suggestions of Cooke. Extensive numerical simulations of the reaction in a flow reactor show that the model predicts the observed topology of the “cross-shaped phase diagram” in which both bistability and oscillations appear as the input flows of the reactant species are varied. The observed hysteresis in the steady-state iodine concentration as a function of I2 flow and a variety of other dynamic behavior are also calculated in agreement with experiment. The remaining discrepancies between theory and experiment appear to result from an overestimation in the model of the stability of the nonradical steady state. A possible remedy for this problem is suggested. © 1982, American Chemical Society. All rights reserved.