Electrochemical oxidation of trichloroethylene using boron-doped diamond film electrodes.

This research investigated the oxidation of trichloroethene (TCE) at boron-doped diamond film electrodes. Flow-through experiments in gastight reactors were performed to determine trichloroethene oxidation products, and rotating disk electrode (RDE) experiments were used to determine TCE oxidation kinetics. RDE experiments were performed over a range in current densities and temperatures in order to elucidate the rate-limiting mechanisms for TCE oxidation. Density functional theory (DFT) simulations were used to investigate the activation barriers for oxidation by direct electron transfer and hydroxyl radicals. Oxidation of TCE produced formate, carbon dioxide, chlorate, and chloride. DFT simulations, experimentally measured apparent activation energies, and linear sweep voltammetry scans indicated that TCE oxidation occurred via direct electron transfer at electrode potentials <2.0 V/SHE, while at higher electrode potentials TCE oxidation also occurred via hydroxyl radicals produced from water oxidation.