ClNO2化学对于全球或区域尺度上痕量气体去除、日间HOx自由基化学初级来源以及二次污染问题的理解具有重要意义。研究表明现有参数化模型难以对N2O5非均相反应生成ClNO2的产率进行准确模拟。目前该方面的机制研究还十分缺乏，本研究拟采用涂膜流动管模拟气溶胶表面，定量N2O5在含氯气溶胶表面非均相反应生成ClNO2的产率。系统表征我国典型气溶胶中颗粒有机物对ClNO2产率的影响，包括人为排放的颗粒有机物，二次有机气溶胶、腐殖酸等，并建立ClNO2产率与颗粒物酸碱度的函数关系。结合模型模拟厘清颗粒有机物和酸碱度对N2O5非均相反应生成ClNO2产率的内在影响机制，建立新的ClNO2产率参数化方案。基于已有的综合外场结果，对HOx自由基收支开展再分析。准确定量ClNO2光解对HOx自由基的贡献，并分析其对O3光化学产生的影响。

Nitryl Chloride (ClNO2) chemistry is important for the understanding of trace gas removal, primary sources of daytime HOx radical chemistry, and secondary pollution at global or regional scales. Previous studies have shown that the existing parametric model is difficult to accurately simulate the yield of ClNO2 in N2O5 heterogeneous reaction. Until now, the mechanism research in this aspect is still very scarce. This study intends to simulate the ambient aerosol surface by using a film-coated flow tube, to quantify the ClNO2 yield in N2O5 heterogeneous reaction on the surface of chlorine-containing aerosol. The effects of particulate organic matter on the yield of ClNO2 in typical aerosols in China were systematically studied, the tested organic matters include primary anthropogenic emitted particulate organic matter, secondary organic aerosol and humic acid, etc. The functional relationship between the yield of ClNO2 and the pH of particulate matter will be established. Combined with the kinetic model, the chemical mechanism of the organic matter and pH of the particles affecting the ClNO2 yield will be probed, and a new ClNO2 yield parameterization will be established. Based on the existing comprehensive field measurement dataset, the HOx radical budget will be reanalyzed. The contribution of ClNO2 photolysis to HOx radicals, and its effect on O3 photochemical generation can be accurately quantified.