A Study on Metal-ion Catalysed Oscillatory behaviour of Pyrogallol based BZ system

The influence of initial reagent concentrations and the temperature dependence on the Belousov-Zhabotinsky (BZ) system with Mn²⁺/Mn³⁺ and Ce³⁺/Ce⁴⁺ redox catalyst, inorganic bromate as oxidant and pyrogallol as organic substrate was studied in aqueous sulphuric acid medium (1.5 mol L⁻¹). The reactions were monitored by potentiometry in oxidation reduction potential (ORP) mode. The aforesaid reagents were mixed with varying concentrations to evolve the optimal concentrations at which the reaction system exhibited better oscillations. The various oscillatory parameters such as induction period (t_in), time period (t_p), frequency (v), amplitude (A) and number of oscillations (n) were derived and the dependence of concentration of the reacting species on these oscillatory parameters was interpreted on the basis of the Field-Koros-Noyes mechanism. Further, the effect of temperature on the aforesaid oscillatory parameters was investigated. The corresponding activation parameters have been determined and the results showed good agreement with Arrhenius temperature dependence.