Theoretical analysis of homogeneous catalysis of electrochemical reactions: steady-state current-potential

This article presents a theoretical analysis of homogeneous redox catalysis in electrochemical reactions. A nonlinear differential system is used as a model in which a nonlinear term is linked to homogeneous reactions. The concentration of the mediator and substrate at a planar electrode is computed using an analytical method under pure kinetic conditions and constant substrate concentration. This simplifies the analysis, which can be achieved with slow-scan rates and concentrations in real-world scenarios. The resulting current-potential responses have an S shape and are independent of the scan rate. The impact of two essential parameters on the current is investigated. The derived analytical expressions show high accuracy when compared to numerical results, which show satisfactory agreement. The limiting cases for the concentration characteristics and current-potential response are also investigated.