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. Amperometrically the oscillations were followed by monitoring the anodic current at a potential of 1.0 V, which corresponds to the electrooxidation of Br− ions. In the Ag+-perturbed BZ reaction we still observe anodic current oscillations due to the electrooxidation of Br− ions more or less loosely bound in AgBr mono- or oligomers. Solid AgBr, however, has been found to be chemically and electrochemically inert in the BZ reaction. The timescale of producing electrochemically inactive AgBr precipitate is a second-order process with a rate constant of 256 M−1 s−1.