In view of the problems existing in catalytic degradation, such as low degradation efficiency, poor dechlorination efficiency and large amount of exhaust gas production, three iron-based bimetallic catalysts were developed for the dechlorination of polychlorinated biphenyls (PCBs) from thermal desorption off-gas, among which manganese-doped iron-based bimetallic catalyst showed the highest degradation efficiency (93.6%) and dechlorination efficiency (92.2%). Specifically, the effect of dechlorination under the air conditions was studied. The GC-MS analysis of intermediate products suggested the presence of three synergistic degradation pathways, namely, hydrodechlorination (HDC), preliminary oxidation, and deep oxidation over manganese-doped iron-based bimetallic catalyst. Through the hydrodechlorination, the chlorine atoms of PCBs were successively removed to obtain the final product biphenyl. During the oxidation stage including preliminary oxidation and deep oxidation, PCBs and intermediates were oxidized by reactive oxygen species (^•OH and O₂^-•). This study provides an efficient and safe dechlorination technology of PCBs in the presence of oxygen with little exhaust gas generated.

针对催化降解存在的降解效率低、脱氯效率差、产生废气量大等问题，研制了三种铁基双金属催化剂，用于热脱附尾气中多氯联苯（PCBs）脱氯。 ，其中锰掺杂的铁基双金属催化剂表现出最高的降解效率（93.6%）和脱氯效率（92.2%）。具体而言，研究了空气条件下的脱氯效果。中间产物的GC-MS分析表明存在三种协同降解途径，即加氢脱氯（HDC）、初步氧化和锰掺杂铁基双金属催化剂的深度氧化。通过加氢脱氯，将多氯联苯的氯原子依次去除，得到最终产品联苯。在包括初步氧化和深度氧化在内的氧化阶段，PCBs和中间体被活性氧氧化（^• OH 和O ₂ ^-• )。本研究提供了一种在氧气存在下产生少量废气的高效、安全的多氯联苯脱氯技术。