Laser Experiments and Theoretical Modeling for the Diagnosis of Bifurcation Sequences of an Oscillating Electrode Reaction

The existence of stable and unstable attractors is investigated experimentally for an electrochemical system consisting of a ring iron electrode immersed in sulfuric acid solution. The applied potential is considered as the bifurcation parameter whereas an external resistance is considered as a second parameter of the system. The stable and unstable states of the system are revealed by combining steady state and laser perturbation experiments with the bifurcation characteristics. A structure of the steady state curve is proposed that can predict the experimental dynamical response. The system is modeled by considering the electrode potential and the concentration of one of the ionic species as dynamical variables. The resulting boundary value problem is studied numerically and a comparison between the experimental and theoretical results is performed. It is shown that the model can predict most of the experimental behavior in a good qualitative agreement.