Study of a catalytic mechanism in additive differential pulse techniques

摘要

The new electrochemical double pulse technique, known as additive differential normal pulse voltammetry (ADNPV) when there is no restriction on the duration of both pulses, and additive differential pulse voltammetry (ADPV) when t(2) t(1), has been applied to a pseudo-first-order catalytic mechanism. The expressions obtained here are applicable to planar and spherical electrodes, of any radius. This is of great interest since the size of the electrode plays an important role in the preponderating of diffusive and kinetics processes. The signal obtained with this technique presents the same morphological characteristics as the triple pulse technique, double differential pulse voltammetry (DDPV) and is more advantageous than DDPV and than the double pulse one, differential pulse voltammetry (DPV). The curves obtained in ADNPV and ADPV for an electrochemical reversible catalytic process present a center of symmetry for any value of equilibrium and rate constants of the chemical reaction. From the coordinates of this point, the kinetic parameters of the chemical reaction and the formal potential can be determined, independently of whether the steady state has been reached or not. [References: 7]