Electrochemical Oxidation of Phenol Using Boron-Doped Diamond Electrodes

Introduction The cleanup of liquids or slurries that contain >1% total organic carbon (TOC), defined as non-wastewater hazardous waste (1), offer particular difficulties for on-site remediation efforts. The electrolytic destruction of organic wastes shows real promise for remediation of a wide variety of organic materials in aqueous waste streams (2). However, the electrochemical oxidation of organic waste is limited with the traditional electrode materials, platinum, ruthenium dioxide, lead dioxide and tin dioxide. The specific limitations arise from low reaction rates and efficiencies, corrosion of the electrodes and fouling and poisoning of the active electrode surfaces. Using phenol as a test compound, the work reported here demonstrates that boron-doped diamond electrodes prepared by chemical vapor deposition (cvd) are not susceptible to these limitations and can oxidize phnol completely to CO2. This communication reviews previous work (3). The oxidation of phenol was chosen as a test reaction because it is one of the most difficult organic molecules to oxidize electrochemically. It is well known for its rapid fouling of the electrode surface due to formation of a blocking polymer layer produced by the polymerization of the phenoxy radicals generated in the initial stages of the reaction (4,5). This results in termination of the reaction in minutes.