On the Limit of Frequency of Electrochemical Oscillators and Its Relationship to Kinetic Parameters

The class of electrochemical oscillators characterized by a partially hidden negative differential resistance in an N-shaped current potential curve encompasses a myriad of experimental examples. We present a comprehensive methodological analysis of the oscillation frequency of this class of systems and discuss its dependence on electrical and kinetic parameters. The analysis is developed from a skeleton ordinary differential equation model, and an equation for the oscillation frequency is obtained. Simulations are carried out for a model system, namely, the nickel electrodissolution, and the numerical results are confirmed by experimental data on this system. In addition, the treatment is further applied to the electro-oxidation of ethylene glycol where unusually large oscillation frequencies have been reported. Despite the distinct chemistry underlying the oscillatory dynamics of these systems, a very good agreement between experiments and theoretical predictions is observed. The application of the developed theory is suggested as an important step for primary kinetic characterization.

National Science Foundation

National Science Foundation [CHE-0955555]

H.V. acknowledges Fundacao de Amparo a Pesquisa do Estado de Sao Paulo [09/07629-6, 141455/2008-0, 306151/2010-3]

H.V. acknowledges Fundacao de Amparo a Pesquisa do Estado de Sao Paulo

Conselho Nacional de Desenvolvimento Cientifico (CNPq)

Conselho Nacional de Desenvolvimento Cientifico (CNPq)