Modelling of reaction_diffusion processes: the theory of catalytic electrode processes at hemispheroidal ultramicroelectrodes

The transient chronoamperometric current for a catalytic electrode reaction (ECʹ reaction) at a hemispheroidal Ultramicroelectrode is reported. This simple new approximate multidimensional analytical expression is valid for all values of time and all values of the rate constant. It is more accurate for all times and large K than for short times and small K. The analytical results are compared with recently presented digital simulation results (Galceran and co-workers, J. Electroanal. Chem 466 (1999) 15) for a disc electrode and are found to be in good agreement.