The application of cyclic voltammetry and digital simulation for the examination of hydroquinone oxidation at a polycrystalline gold electrode in HClO4

The electrochemical behaviour of hydroquinone was examined using cyclic voltammetry at a polycry-stalline gold electrode in 0.5M HClO4. The peak-to-peak potential separation (ΔEp) has been found to be 489 mV vs. SCE. The results indicate that the reductive peak coupled with the oxidative peak of hydroquinone is absent due to the presence of a chemical step following the electron transfer. The relevant chemical and electrochemical parameters were determined experimentally via cyclic voltam-metry. A Theoretical study via electrochemical simulation based on oxidation behavior has been perfo-rmed for the cyclic voltammograms obtained on the surface of an Au electrode. The kinetic data extracted from cyclic volta-mmograms was confirmed and verified with the help of digital simulation. The homogeneous and heterogeneous rate constants were estimated by comparing the experimental cyclic voltammetric resp-onses with the digital simulated results. On the basis of the electrochemical behavior we proposed an ECE mechanism for the electrochemical oxidation of hydroquinone. Digital simulation was used also to confirms the proposed ECE pathway of electrode reaction.