Bifurcations induced by the electrode surface area during the electrochemical oxidation of bisulfite

Electro-oxidation behavior of bisulfite was found to depend qualitatively on the surface area of a glassy carbon electrode, where a transition from stable to oscillatory behavior took place as the surface area of the working electrode was increased to above a critical value. The size-dependent nonlinear behavior was observed at both potentiostatic and galvanostatic conditions. Preliminary characterization with electrochemical impedance spectroscopy illustrates the emergence of a hidden-negative differential resistance at the above threshold surface area. The conclusion that the studied system belongs to the class of HN-NDR type electrochemical oscillator is consistent with the result that oscillations also take place under a galvanostatic control. [Display omitted] •Electrode surface area was found to induce consecutive bifurcations.•Current and potential oscillations were observed during the oxidation of bisulfite.•EIS suggests that the system belongs to a HN-NDR type electrochemical oscillator.