BELOUSOV-ZHABOTINSKY OSCILLATIONS DURING THE CHEMICAL OR ELECTROCHEMICAL GENERATION OF AG+ IONS

The oscillatory Belousov-Zhabotinsky reaction has been studied in the presence of Ag+ ions using potentiometric and amperometric methods. Am perometrically, the oscillations were followed by monitoring the anodi c current at a potential of 1.0 V, which corresponds to the electrooxi dation of Br- ions. In the Ag+-perturbed BZ reaction we still observe anodic current oscillations due to the electrooxidation of Br- ions mo re or less loosely bound in AgBr mono- or oligomers. Solid AgBr, howev er, has been found to be chemically and electrochemically inert in the BZ reaction. The timescale of producing electrochemically inactive Ag Br precipitate is a second-order process with a rate constant of 256 M -1 s(-1).