Abstract
The CuS04-catalyzed reaction of hydrogen peroxide with thiocyanate ion is the first example of a homogeneous, liquid phase, halogen-free system that oscillates under batch conditions. A detailed mechanism is proposed consisting of 30 reactions and 26 variables. The mechanism is constructed from two nonautocatalytic mechanisms for the subsystems alkaline H202-CuS04 and H202-KSCN, coupled through various intermediates to construct a feedback network, which leads to oscillatory behavior in both batch and flow configurations. The integrated mechanism simulates very well the experimentally observed oscillations in absorbance and 02 evolution and two of the three kinds of bistability in a continuously stirred tank reactor. Two alternative mechanisms are also considered, providing insight into the general properties of oscillatory mechanisms.