Carter Kimberly E, Farrell James
Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, Arizona 85721, USA.
Environ Sci Technol. 2009 Nov 1;43(21):8350-4. doi: 10.1021/es9017738.
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.
本研究调查了硼掺杂金刚石薄膜电极上三氯乙烯（TCE）的氧化情况。在气密反应器中进行了流通实验以确定三氯乙烯氧化产物，并用旋转圆盘电极（RDE）实验来确定TCE的氧化动力学。为阐明TCE氧化的限速机制，在不同电流密度和温度范围内进行了RDE实验。采用密度泛函理论（DFT）模拟研究了直接电子转移和羟基自由基氧化的活化能垒。TCE氧化产生了甲酸盐、二氧化碳、氯酸盐和氯化物。DFT模拟、实验测量的表观活化能和线性扫描伏安法扫描表明，在电极电位<2.0 V/SHE时，TCE通过直接电子转移发生氧化，而在较高电极电位下，TCE也通过水氧化产生的羟基自由基发生氧化。
