State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji Advanced Membrane Technology Center, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji Advanced Membrane Technology Center, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
Water Res. 2023 May 1;234:119810. doi: 10.1016/j.watres.2023.119810. Epub 2023 Mar 1.
Halogenated organic pollutants are often found in wastewater effluent although it has been usually treated by advanced oxidation processes. Atomic hydrogen (H*)-mediated electrocatalytic dehalogenation, with an outperformed performance for breaking the strong carbon-halogen bonds, is of increasing significance for the efficient removal of halogenated organic compounds from water and wastewater. This review consolidates the recent advances in the electrocatalytic hydro-dehalogenation of toxic halogenated organic pollutants from contaminated water. The effect of the molecular structure (e.g., the number and type of halogens, electron-donating or electron-withdrawing groups) on dehalogenation reactivity is firstly predicted, revealing the nucleophilic properties of the existing halogenated organic pollutants. The specific contribution of the direct electron transfer and atomic hydrogen (H*)-mediated indirect electron transfer to dehalogenation efficiency has been established, aiming to better understand the dehalogenation mechanisms. The analyses of entropy and enthalpy illustrate that low pH has a lower energy barrier than that of high pH, facilitating the transformation from proton to H*. Furthermore, the quantitative relationship between dehalogenation efficiency and energy consumption shows an exponential increase of energy consumption for dehalogenation efficiency increasing from 90% to 100%. Lastly, challenges and perspectives are discussed for efficient dehalogenation and practical applications.
卤代有机污染物通常存在于废水废水中，尽管它通常已通过高级氧化工艺进行处理。原子氢（H*）介导的电催化脱卤，具有打破强碳卤键的优异性能，对于从水中和废水中有效去除卤代有机化合物越来越重要。本综述总结了近年来在电催化水解除卤代有毒有机污染物方面的最新进展。首先预测了分子结构（例如，卤原子的数量和类型，供电子或吸电子基团）对脱卤反应性的影响，揭示了现有卤代有机污染物的亲核性质。已经确定了直接电子转移和原子氢（H*）介导的间接电子转移对脱卤效率的具体贡献，旨在更好地理解脱卤机制。熵和焓的分析表明，低 pH 的能量势垒低于高 pH，有利于质子向 H*的转化。此外，脱卤效率与能耗之间的定量关系表明，脱卤效率从 90%增加到 100%时，能耗呈指数增加。最后，讨论了卤代去除的挑战和展望以及实际应用。
