Abstract:

The oscillations of P-H2NC6H4COOH-KBrO3- H2SO4 system are studied. The dual-frequency oscillations are found in this system. Furthermore, the influences of initial reaction conditions (concentrations of reactants and temperature) metal-ion catalysts and several additives on oscillating behaviors are concluded. These experimental phenomena suggested that the dual-frequency oscillations are controlled by two types of mechanism, one is bromide-ion controlling to the lower frequency oscillations, the other is non-brominde ion controlling to the higher ones, in which the substrate radicals play an important role. Moreover, these mechanisms are competing in the reaction system when the situation is fit for each one. Some interpretations about this are approached from the analysis of the composion of substrates and the viriation of potential during the reaction.

Key words: BZ reaction, Dual-frequency oscillation, Bromide-ion controlling, Nonbromide-ion controlling