The electroreductive cleavage of carbon‐chloro bonds has attracted increasing attention from both environmental and mechanistic points of view over the past decades, taking into consideration a large variety of chlorinated organic compounds. Important discoveries have been made on the underlying electron/hydrogen transfer mechanisms and the enhancement of dechlorination performance for electrocatalysis purposes over the last years. However, there is still missing a combined knowledge from individual researches to specially elucidate the electroreductive dehalogenation mechanisms of organic chlorides. Herein, we summarize the diverse electrochemical strategies applied to reductive dehalogenation of chlorinated environmental pollutants, including direct electrochemical reduction, electrocatalytic hydro‐dechlorination and electrochemically mediated reduction methods, and, especially, highlight the differences in reductive dehalogenation mechanisms. Specifically, direct electron transfer is the most common dechlorination mechanism involved in the direct electrochemical reduction of organic chlorides, in which the electron transfer to C−Cl bonds can be classified as concerted or stepwise dissociative electron transfer mechanism. Indirect atomic hydrogen reduction is the primary dechlorination mechanism in the electrocatalytic hydro‐dechlorination process, which often competes with the direct electrochemical reduction route. Electrochemically mediated reduction, as another indirect route, uses a redox‐active mediator to indirectly transfer electrons from cathode to organic chlorides, resulting in reductive dehalogenation reaction. Moreover, the effects of critical factors on the dehalogenation reactivity and mechanisms are also discussed to better demonstrate the electroreductive dehalogenation of organic chlorides. Lastly, this contribution highlights recent relevant advances in electroreductive dehalogenation issues, as well as the challenges and potentials of this process.

中文翻译：

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氯化环境污染物电还原脱卤机理的见解

考虑到多种氯化有机化合物，从环境和机理的角度来看，碳-氯键的电还原裂解已引起越来越多的关注。在过去的几年中，在潜在的电子/氢转移机理以及用于电催化目的的脱氯性能的增强方面已取得重要发现。然而，仍然缺少个别研究的综合知识来专门阐明有机氯化物的电还原脱卤机理。在这里，我们总结了应用于电化学环境污染物还原脱卤的各种电化学策略，包括直接电化学还原，电催化加氢脱氯和电化学介导的还原方法，尤其是突出了还原性脱卤机理的差异。具体来说，直接电子转移是有机氯化物直接电化学还原中最常见的脱氯机理，其中电子转移至C-Cl键可分为协调或逐步解离电子转移机理。间接原子氢还原是电催化加氢脱氯过程中的主要脱氯机理，通常与直接电化学还原途径竞争。电化学介导的还原是另一种间接途径，它使用氧化还原活性介体将电子从阴极间接转移到有机氯化物，导致还原性脱卤反应。此外，还讨论了关键因素对脱卤反应性的影响及其机理，以更好地证明有机氯化物的电还原脱卤作用。最后，这一贡献突出了在电解还原脱卤问题上的最新进展，以及该方法的挑战和潜力。