MECHANISTIC ANALYSIS OF ELECTROCHEMICAL OSCILLATORS USING DERIVATIVE FEEDBACK-CONTROL TECHNIQUES

Derivative control was applied to electrochemical oscillators under po tentiostatic as well as galvanostatic conditions; i.e., the time deriv ative of a measured quantity (such as the current or the concentration of an electrochemical species) is fed back to the externally applied voltage or, respectively, current. In particular cases the control led to stabilization of the unstable node, i.e., suppression of oscillati ons. By comparison with model calculations, it is shown that the resul t of the derivative control provides valuable information about the me chanism of an electrochemical oscillator and the role of certain speci es.