Mass transport and dynamical instabilities in a model electrocatalytic process with a preceding chemical reaction

Abstract

The influence of mass transport on the occurrence of periodic current oscillations and bistability in a model electrocatalytic process with a preceding homogeneous first-order chemical reaction in the Nernst diffusion layer for different diffusion coefficients of species involved in the chemical reaction is shown. The impacts of the diffusion coefficients of electrochemically active and inactive species, as well as the preceding chemical reaction rate constants on the emergence of these dynamical instabilities are uncovered. The effect of the aforementioned parameters on frequency of oscillations is determined. The peculiarities of the system behavior at the bifurcation points are demonstrated in the Nyquist and Bode plots. For the first time, the role of diffusion coefficient of inactive species in these nonlinear processes is presented theoretically.