Glassy carbon surface effects on the electroreduction of aromatic carbonyl compounds Part III: Vanillin

Abstract

Voltammetric studies of vanillin reduction in aprotic (DMF) and aqueous media in three different pH ranges on glassy carbon electrodes (GCE's) are presented. The formation and stability of anion radicals and their reactivity towards protonating agents are discussed. On a partially polished or pretreated GCE in DMF as well as on a polished GCE in neutral aqueous media, a new time-dependent surface prewave is noticed. The evidence indicates that this prewave is due to the interaction of acidic functional groups present on the GCE surface with vanillin. In acidic, neutral and alkaline media, the main reduction process occurs at potentials close to the background reduction potential region.