Influence of mixed cerium(IV) sulphate and ferroin catalysts on the oscillatory redox reaction between malonic acid and bromate

Abstract

We examine the influence of mixed cerium(IV) sulphate and ferroin catalysts in the oscillating reduction of bromate by malonic acid. The tests were made by potentiometric and spectrophotometric methods. Results are shown as number of cycles and both maximum and minimum of potential vs. time. The mixed cerium(IV)–ferroin catalysts have almost the same effect as pure ferroin at the beginning and as pure cerium(IV) at the end. The number of cycles is quite steady, but the frequency of oscillations of the cerium(IV) catalyst is very low and very different from that of the mixed catalysts and of pure ferroin.