Additive Differential Pulse Voltammetry for the Study of Slow Charge Transfer Processes at Spherical Electrodes

Abstract

The application of additive differential pulse voltammetry to the study of the kinetics of a charge transfer process is studied. A simple analytical solution is presented, valid for spherical electrodes of any size and for electrode processes of any reversibility. From this solution, valuable diagnostic criteria for the elucidation of the electrochemical reversibility are established based on the variation of the ADPV signal with the duration of the potential pulses, the electrode radius and the pulse height. Working curves for the determination of the kinetic parameters are also given. The value of the ADPV technique is experimentally demonstrated by studying the kinetics of the reduction of 3-nitrophenolate À and europium 3 + at mercury hemispherical microelectrodes.

Simulation of Alternative Differential Multi-pulse Voltammetry. Evaluation of the Electrochemical Reversibility by the Voltammogram Symmetry

“…|∆Φp,r / ∆Φp,f| = 0.79) as a result of the concentration gradient of redox components in diffusion layer near the electrode surface. These observations are different from the results given by Laborda et al [12,13] where |∆Φp,r / ∆Φp,f| = 1 and Ec = E° (in case of a reversible redox reaction) as a result of different potential-time waveforms. More precisely, in ADMPV at the "middle-pulse" potential, the product Red generated during the forward/cathodic pulse diffuses away during the delay time (τ) separating the two pulses with opposite polarities.…”

“…These are in accordance with the results given in references. [12,15] On the other hand, by increasing the values of τ and tp simultaneously, both forward/cathodic and reverse/anodic peak currents decrease ( Figure 2B). Furthermore, unlike data from Laborda et al [13] the net ADMP voltammogram is not a result of the addition of two differential pulse voltammograms.…”

Comparison between double pulse and multipulse differential techniques

“…In previous papers [4,28,29], the striking splitting of the peakshaped curves for quasireversible processes with small or large values of the transfer coefficient (a) has been described for DDPV and Additive Differential Pulse Voltammetry. In Fig.…”

Recent Advances in Voltammetry

“…The quantification of the electrode kinetics is possible from single‐point fitting of the DDPV and ADPV curves –. For this, the peak height (in DDPV) and maximum current (in ADPV) are more sensitive in the case of quasi‐reversible processes whereas the DDPV peak potential and the ADPV crossing potential are more appropriate for irreversible electrode reactions.…”