Degradation of 2-Chlorophenol Using a Pd/MWNTs Gas Diffusion Electrode in the Divided Cell

In a diaphragm electrolyze system with a Ti/RuO2/IrO2 anode and the Pd/MWNTs gas diffusion cathode, the degradation of 2-chlorophenol was fully studied by the electrochemical reduction and the simultaneous oxidation of the cathode and anode. The results indicated that the Cl- removal reached 90.5% after 80 min electrolysis with H2 feeding. After 120 min electrolysis, the removal of 2-chlorophenol in the anodic and cathode compartments were 88.8% and 98.5%, respectively. Additionally, the TOC removal reached 75% and 85.6% in the anodic and cathodic compartment respectively after 140 min. By the UV scanner analysis of the electrolyte, the 4-chlorophenol and benzoquinone were oxidized by the oxides formed on the cathode, while the benzoquinone was found accumulated in the anodic compartment. Based on the analysis of electrolysis intermediates using high performance liquid chromatography (HPLC) and ion chromatography (IC), the electrolysis degradation of 2-chlorophenol was proposed containing the intermediates, such as phenol, hydroquinone, benzoquinone, maleic acid, fumaric acid, succinic acid, malonic acid, oxalic acid, acetic acid and formic acid.