ANALYSIS OF THE CYCLIC VOLTAMMETRIC RESPONSES EXHIBITED BY ELECTRODESMODIFIED WITH MONOLAYERS OF CATALYSTS IN THE ABSENCE AND PRESENCE OF SUBSTRATES

The cyclic voltammetric responses to be expected from electrodes to wh ich monolayers of redox catalysts are attached are calculated in the a bsence and presence of substrates for the catalyst. The consequences o f interactions among the attached catalyst molecules and/or finite rat es of the electrode reaction are treated explicitly. Relationships amo ng peak currents, peak and half-peak potentials of the pure catalytic waves and the rate constant for the catalytic reaction are derived, fr om which the rate constant of the catalytic reaction can be evaluated. When the rate of the electrode reaction for the catalyst is high, the pure catalytic component of the observed voltammetric responses can b e obtained by subtraction of the response from the catalyst in :he abs ence of substrate from the observed response in the presence of substr ate. However, this convenient property is lost as the rate constant of the electrode reaction decreases. A kinetic parameter was found empir ically from which the experimental conditions required to allow the si mple subtraction procedure to be used reliably even in the presence of slow electron transfer were established.