EN
This report investigated nonlinear spatiotemporal behavior in the ferroin-bromate-pyrocatechol reaction, in which two stages of wave formation, separated by several hours of quiescent period, were observed. In addition to its great photosensitivity, the second stage wave activity could undergo spontaneous breakups at broad reaction conditions. Analysis based on one-dimensional space-time plot suggests that the breakup was caused by propagation slowdown of the leading wave. Due to the presence of coupled autocatalytic reactions, the propagation of the initial and the second stage waves exhibited different and subtle responses to the variation of the concentration of each reagent.