氯苯低压热解的原位同步辐射光电离质谱研究

氯苯类化合物及其高温热解产物是大气中重要的一类污染物, 对氯苯热解路径的研究可为防止或减少相关污 染物的排放提供基础理论指导。利用原位同步辐射光电离质谱技术 (SR-PIMS) 在 4 kPa 和 873∼1373 K 条件下开展了 氯苯流动管反应器低压热解研究, 实时鉴定了包括烯烃、芳烃和氯化芳烃等 16 种热解产物, 获得了这些产物的摩尔 分数随热解温度的变化规律。研究表明: 苯炔 (o-C6H4) 是氯苯热解形成小分子路径的关键中间体。对比本组之前氯 苯常压流动管热解的实验结果, 发现低压减弱了氯化芳烃等含氯有机物的形成途径, 表明压力条件会影响氯苯重要次 级热解产物氯化芳烃的形成。

Chlorobenzene pyrolysis at low pressure by in-situ synchrotron radiation photoionization mass spectrometry

Chlorobenzene compounds and their high-temperature pyrolysis products are one kind of the important pollutants in the atmosphere. The research on the pyrolysis path of chlorobenzene can provide basic theoretical guidance for preventing or reducing the emission of related pollutants. The pyrolysis of chlorobenzene in a flow tube reactor was studied at 4 kPa and 873∼1373 K by in-situ synchrotron radiation photoionization mass spectrometry (SR-PIMS). 16 products including olefin, aromatic hydrocarbons, and chlorinated aromatic hydrocarbons were detected in real time. Mole fractions of these products were obtained as function of pyrolysis temperature. The results show that o-benzyne is a key intermediate for the formation of small molecules in the pyrolysis of chlorobenzene. Besides, compared with the pyrolysis results of chlorobenzene at atmospheric-pressure observed before in this group, it was found that low pressure can reduce the formation pathways of chlorine-containing organics such as chlorinated aromatic hydrocarbons, an important secondary pyrolysis product of chlorobenzene, which indicates that pressure conditions can affect the formation and the following atmospheric emission of chlorinated aromatic hydrocarbons.