Generalized Nernst layer model for convective-diffusion transport. Numerical solution for bromide ion electroreduction on inactive rotating disk electrode under steady state conditions

The process of electroreduction of bromate anion BrO3 (-) from aqueous solutions on catalytically inactive (e.g., carbon) electrodes is theoretically described in the framework of the generalized Nernst layer model in which the Nernst-layer thickness is chosen independently for each system's component according to the Levich formula. For this system, the numerical algorithm is developed for solving the system diffusion- kinetic equations for the case of excessive content of protons in solution and one-dimensional transport (corresponding to RDE) under stationary conditions. The results are compared with conclusions of the approximate analytical theory proposed for the same system in our recent study (J. Electroanal. Chem., 2016, vol. 779, p. 146). The closeness of the numerical and analytical data makes it possible to conclude that both approaches can be used for solving this problem. Deviations are observed only when the approximations lying in the basis of the corresponding analytical relationships are violated.