Development of Efficient Electrolytic Systems for Dehalogenation of Aromatic Halogen Compounds and Recovery of Halogen

对致癌的多氯联苯和二恶英等有害氯代芳香族化合物的高效降解系统，以及从含溴电子材料和X射线造影剂中回收溴和碘的高效系统的需求强烈。因此，我们开发了一种高效的循环电解系统，该系统采用内涂Pd黑的钯管制成的阴极。在酸性水溶液中的电解过程中，只包含底物的溶液循环通过钯管。因此，即使在一次通过中，该系统对含有对氯苯酚的水蒸气也实现了100%的脱氯效率。各种溴代苯和碘代苯的电催化脱溴和脱碘也是成功的。碘化胺等多碘苯衍生物作为X射线造影剂的脱碘反应顺利进行，碘的回收率较高。利用多根钯管成功地进行了放大实验。此外，该体系还成功地应用于不同不饱和化合物的电催化加氢以及对染料废液的处理。

Highly efficient degradation systems of harmful chlorinated aromatic compounds such as carcinogenic PCBs and dioxins and recovery systems of bromine and iodine from nonflammable bromine-containing electronic materials and X-ray contrast agents are strongly demanded. Therefore, we have developed a highly efficient circulating electrolytic system, which uses a cathode made of a palladium tube coated on the inside with Pd black. A solution containing only substrate was circulated through the Pd tube during electrolysis in an acidic aqueous solution. Thus, even in a single pass, the system achieved a 100% dechlorination efficiency for an aqueous stream containing p-chlorophenol. Electrocatalytic debromination and deiodination of various bromoand iodobenzenes were also successful. Deiodination of polyiodobenzene derivatives like iopamidol as a X-ray contrast agent proceeded smoothly, and iodine was recovered efficiently. The scale up was successfully carried out using multiple Pd tubes. Moreover, this system was successfully applied to electrocatalytic hydrogenation of different unsaturated compounds as well as treatment of waste dyestuff solutions.