Electrochemical incineration of chloranilic acid using Ti/IrO2, Pb/PbO2 and Si/BDD electrodes

The electrochemical oxidation of chloranilic acid (CAA) has been studied in acidic media at Pb/PbO2, boron-doped diamond (Si/BDD) and Ti/IrO2 electrodes by bulk electrolysis experiments under galvanostatic control. The obtained results have clearly shown that the electrode material is an important parameter for the optimization of such processes, deciding of their mechanism and of the oxidation products. It has been observed that the oxidation of CAA generates several intermediates eventually leading to its complete mineralization. Different current efficiencies were obtained at Pb/PbO2 and BDD, depending on the applied current density in the range from 6.3 to 50 mAcm-2. Also the effect of the temperature on Pb/PbO2 and BDD electrodes was studied. UV spectrometric measurements were carried out at all anodic materials, with applied current density of 25 and 50 mAcm-2. These results showed a faster CAA elimination at the BDD electrode. Finally, a mechanism for the electrochemical oxidation of CAA has been proposed according to the results obtained with the HPLC technique