Hysteresis and complex oscillations of the uncatalysed Belousov–Zhabotinskii reaction in a stirred flow reactor

Abstract

The experimental behaviour of an uncatalysed Belousov–Zhabotinskii reaction (gallic acid–KBrO₃–H₂SO₄ system) in a continuous-flow, stirred tank reactor (CSTR) has been studied for the first time. At low inflow concentrations of gallic acid (GA), hysteresis or ‘bistability’ has been observed. At higher GA inflow concentrations a sequence of simple and mixed-mode oscillations is found between the two stable steady states at long and short residence time. A new form of complex waveform is also reported. The mechanistic characterisation of the GA–BrO^–₃ reaction in acidic media is discussed.