Electrochemical oxidation of organics at metal oxide electrodes: The incineration of oxalic acid at IrO2–Ta2O5 (DSA-O2) anode

The electrochemical incineration of oxalic acid (OA) at Ti/IrO2–Ta2O5 (DSA-O2) anode was investigated to find the influence of the operative parameters on the performances of the process. Polarization curves and chronoamperometric measurements indicate the probable occurrence of a direct electrochemical oxidation of OA at the surface of the DSA anode. In incineration electrolyses, the performances of the process in terms of OA conversion and current efficiency dramatically depend on the adopted operative conditions. Interestingly, very high OA removal and current efficiency were obtained when the process was performed at relatively high temperatures (50 °C) or in the presence of NaCl. The experimental results are in good agreement with the previsions of a simple theoretical model previously developed.