Electrochemical oxidation of phenol at boron-doped diamond electrode

The electrochemical oxidation of phenol at synthetic boron-doped diamond th in film electrode (BDD) has been studied in acid media by cyclic voltammetr y, chronoamperometry and bulk electrolysis. The results have shown that in the potential region of water stability (E < 2.3 V vs. SHE) they can occur direct electron transfer reactions on BDD surface that results in electrode fouling due to the formation of a polymeric film on its surface. While dur ing electrolyses in the potential region of water decomposition (E > 2.3 V vs. SHE), indirect oxidation reactions can take place by electrogenerated a ctive intermediates, probably hydroxyl radicals, which can avoid electrode fouling. Depending on the values of applied current, and phenol concentrati on it is possible to obtain the complete combustion of phenol to CO, or the partial oxidation of phenol to other aromatic compounds (benzoquinone, hyd roquinone, catechol). (C) 2001 Elsevier Science Ltd. All rights reserved.