Excitable dynamics in the bromate–sulfite–ferrocyanide reaction

Abstract

Using the bromate–sulfite–ferrocyanide (BSF) reaction in a continuously stirred tank reactor (CSTR) we study the relations between excitability, oscillations and bistability. Two kinds of excitability associated with either direct or indirect initiation of the autocatalytic production of the H⁺ ions are found by using pulsed addition of H⁺ or OH⁺ ions, respectively. Threshold dynamics in both cases are examined. Experimental findings are compared with calculations based on a mechanism of successive reduction of bromate by protonated forms of sulfite. The model reproduces most of the dynamics in the CSTR including both modes of excitable behaviour.