Steady-State Limiting Current at a Microdisc

5 Steady-State Limiting Current at a Microdisc Problem 

The incident transport-limited flux at any radius, r, on the surface of a microdisc electrode under steady-state diffusion conditions is given by 

Use this equation to predict the steady-state limiting current at the microdisc electrode for an n-electron process. Comment on any possible limitations of the 

The expression for / is derived by assuming a zero concentration of the electroactive species on the disc surface, corresponding to diffusion control. However, the expression predicts the flux to become infinite at the disc edges  

In practice, this is physically unrealistic since finite electrode kinetics must restrict the flux to a finite value in the vicinity of the disc edge. 

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