AN INTEGRAL-TRANSFORM FORMULATION FOR THE REACTION DISTRIBUTION ON A STATIONARY-DISK ELECTRODE BELOW THE LIMITING CURRENT

Current flow on a disk electrode can be described by means of a partial differential equation on a half-infinite, two-dimensional space. A numerical solution method to the steady-state version of this problem is developed using an integral transform which reduces the problem to an integral equation on a bounded one-dimensional space. The formulation yields approximate solutions by analytic means, which will be discussed in a future report. Simulation results are presented for the reaction profile over the disk surface (current distribution) and the corresponding surface potential and concentration profiles. The model can be used to identify conditions for which the current distribution will be uniform—a condition that facilitates the measurement of charge-transfer rates. Simulation results are used to explain why electrodes of smaller radii (microdisks) are superior for the measurement of charge-transfer rates. © 1990, The Electrochemical Society, Inc. All rights reserved.