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A Kinetic Study on Catechol-Based Belousov–Zhabotinsky Reaction



The present investigation pertains to the kinetic study on bromate-driven and manganese ion catalyzed Belousov–Zhabotinsky oscillatory chemical reaction having catechol (1,2-dihydroxybenzene) as the organic substrate in aqueous acid media at 30 ± 0.1oC under stirred conditions. Although some polyphenols as chemical oscillators are known in the literature but the role of catechol has been marginalized. The reaction system with catechol shows long-time series of periodic as well as aperiodic oscillations, which were monitored potentiometrically in the oxidation reduction potential (ORP) mode under batch conditions. The various oscillatory parameters such as induction time (tin), time period (tp), amplitude (A), and number of oscillations (N) were obtained by drawing a plot between redox potential (mV) versus time (s). It is found that the oscillatory parameters of the system vary with the concentration of the reacting species. The reaction system was also studied in different aqueous acid media, but the detailed studies with respect to experimental parameters have been made in aqueous sulfuric acid medium as it showed a broad oscillatory window and better oscillatory characteristics. Moreover, the oscillatory parameters in general and induction time in particular vary significantly with temperature (15 to 45 ± 0.1oC). The activation parameters of the system have also been calculated. The oscillatory behavior of the reaction system was also confirmed spectrophotometrically. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 45: 141–151, 2013