A General Method for Electrochemical Simulations. 2. Application to the Simulation of Steady-State Currents at Microdisk Electrodes: Homogeneous and Heterogeneous Kinetics

Abstract

ILU preconditioned Krylov subspace methods are used with conformal mappings to simulate the steady-state response of microdisk and hemispherical electrodes with the influence of homogeneous and heterogeneous kinetics. For the microdisk electrode, the conformal mapping of Amatore and Fosset (J. Electroanal. Chem. 1992, 328, 21) is shown to be superior to that of Verbrugge and Baker (J. Phys. Chem. 1992, 96, 4572), both in its efficiency for simple electron-transfer problems and in terms of the conditioning of the matrix it produces. The efficiency improvement arising from the use of multipoint Taylor series expressions for boundary conditions is investigated and is found to be highly significant for these systems where edge singularities are removed by the conformal mapping. Convergence at high rate constants is also addressed. The simulations were used to generate working curves at microdisk and spherical/hemispherical electrodes for ECE, DISP1, EC2E, DISP2, and EC‘ mechanisms and a working surface for qu...