Temperature-induced bifurcations in the Cu(II)-catalyzed and catalyst-free hydrogen peroxide-thiosulfate oscillating reaction

摘要

We study the oxidation dynamics of thiosulfate ions by hydrogen peroxide in the presence of trace amounts of copper(II) using the reaction temperature as a control parameter in a continuous flow stirred tank reactor. The system displays period-doubling, aperodic, and mixed-mode oscillations at different temperatures. We are able to simulate these complex dynamics with a model proposed by Kurin-Cs?rgei et al. The model suggests that the Cu ~(2+)-containing term is not essential for the observed oscillations. We find small-amplitude and high-frequency oscillations in the catalyst-free experimental system. The reaction between H_2O_2 and S _2O_3~(2-) contains the core mechanism of the H _2O_2-S_2O_3~(2-)-Cu ~(2+) and H_2O_2-S_2O_3~(2-)-SO_3~(2-) oscillatory systems, while the Cu ~(2+) and SO_3~(2-) modulate the feedback loops so as to strengthen the oscillatory dynamics.