利用同步辐射光电离时间分辨质谱技术研究不饱和酯类有机物与OH、Cl自由基的大气氧化反应

不饱和酯类化合物(如甲基丙烯酸甲酯、乙酸丙烯酯等)是重要化工原料，使用量大，具有排放量大、挥发性高、毒性大等特点，对环境造成污染，危害人类健康。它们主要通过OH、Cl等引起的氧化反应进行降解。但相关研究没有考虑OH、Cl自由基不同的反应通道影响，对反应产物及其异构体、中间体的形成机理缺乏研究，严重影响大气污染模拟的精确性。.利用激光光解产生自由基和反应流动管实验装置，结合同步辐射光电离，进行时间分辨质谱测量，开展OH、Cl自由基引起的大气氧化反应动力学研究，获得各反应产物及其异构体、中间体，直接测量其反应速率常数，掌握重要的反应通道和关键中间体；结合量化计算，研究不同大气条件下(有/无NOx)氧化反应降解机理，并比较异同点。充分认识它们对大气环境污染的影响因数，为大气污染模拟研究提供科学数据，提高大气污染模拟的精确性，为监测和减少大气污染提供科学指导，特别对工业污染地区具有重要现实意义。

Unsaturated esters (such as methyl methylacrylate--MMA and allyl acetate--AA) found in the atmosphere are important chemical materials which have been widely used in industry. The large emission, high volatility, and toxicity make unsaturated esters a potential source of environmental concerned in the atmosphere. In the atmosphere, the major degradation pathways of these esters are the reactions with tropospheric oxidants, mainly with OH and Cl radicals. Several studies were conducted on the kinetics of these compounds without considering the different addition reaction channels of OH and Cl radicals, and formation mechanisms of the products and intermediates are lack of detailed discussions. Combined laser flash photolysis and slow flow tube system with SR photoionization time-resolved mass spectrometer, the OH-, and Cl-initiated atmospheric oxidations will be carried out to measure directly reaction products, yields, and rate constants. The products and intermediates formed by different addition channels or extraction channels of OH or Cl radicals are analyzed according to the time resolved mass spectroscopies of the products. Combined with quantum chemical calculations, insights into OH- and Cl-initiated oxidation mechanisms of unsaturated esters under different atmospheric conditions (with/without NOx) are gained, and reliable kinetic data are provided for accurate simulation of reaction progresses in the atmospheric chemistry, which could provide useful information to distinguish and reduce atmospheric pollutions, and could have great practical significance especially in industrial areas.