engleski

Cyclic normal pulse voltammetry in the study of EC reactions

In this communication a theory of cyclic normal pulse voltammetry (CNPV) of a simple reversible electron transfer followed by irreversible chemical reaction is presented: Ox + ne- <---> Red - kf -> P where kf is the rate constant of chemical reaction. The effect of dimensionless chemical kinetic parameter, Kc = kf∙tp (where tp is the pulse duration), on CNP voltammogram was examined. Chemical reaction (i.e. increasing the value of Kc) changes the appearance of forward branch of voltammogram from wave to peak. The relationship between diffusion and maximum reduction current ratio and logarithm of Kc is analysed theoretically and the criterion for recognition of the EC mechanism is given. Experimentally, the value of kf can be estimated from the linear relationship of id/imax on log(tp).

cyclic normal pulse voltammetry; EC mechanism; theory

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