Abstract: The complex kinetics of the reaction of periodate and sulfite has been investigated. This is a novel periodate-based oscillator. In excess of sulfite and in acidic medium（pH< 3）, batch single-peak phenomena and CSTR sustained oscillations of Pt 、I－ and pH potential, and the complex dynamics in a semibatch are obtained, while the alternative change of color from colorless to brown is also observed. The oscillation behavior is related to [KIO4]0/[Na2SO3]0 ratio and acidity. A possible reaction mechanism, which consists of an autocatalytic production of H＋(positive feedback) and a H＋-consuming pathway (negative feedback), along with the production and elimination of iodine, could fairly explain the complex dynamical behavior.

Key words: Chemical oscillation, Complex kinetics, Periodate, Sulfite