Abstract Heterogeneous reactions of various atmospheric gaseous pollutants on particle surfaces are important pathways for the formation of secondary aerosols. However, these heterogeneous reactions are inevitable affected by each other in the real atmosphere. In this study, the impacts of the heterogeneous uptake of NO2 on the conversion of acetaldehyde on the particle surfaces in the absence and presence of simulated solar irradiation were investigated by using diffuse reflectance infrared spectroscopy (DRIFTS) at 298 K. It is found that in the absence of simulated solar irradiation the hydration reaction and subsequent polyoligomeric reaction as well as oligomeric reaction of CH3CHO are promoted by the pre-adsorption of NO2 for a short reaction time, but these reactions are significantly hindered, accompanied with the slightly enhanced formation of crotonaldehyde and adsorbed acetate by the pre-adsorption of NO2 for a longer time. In the presence of simulated solar irradiation, the occurrence of the aldol condensation and the oxidation of CH3CHO are promoted by the combined impacts of illumination, hydrogen bond (H-bond) catalysis, the enhanced surface acidity and the formed nitrite and nitrate, especially, the photolysis of the formed nitrite and nitrate, whereas the hydration reaction and subsequent polyoligomeric reaction as well as oligomeric reaction of CH3CHO molecules are suppressed. Meanwhile, the hydrogen bond catalysis for aldol condensation is significantly enhanced by light irradiation, showing a combined result of hydrogen bond catalysis and illumination. The heterogeneous reaction mechanism is proposed, and atmospheric implications based on these results are discussed in this study.

中文翻译：

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在模拟太阳辐射不存在和存在的情况下，二氧化氮的异质吸收对乙醛转化为γ-氧化铝的影响

摘要 大气中各种气态污染物在颗粒表面的非均相反应是形成二次气溶胶的重要途径。然而，这些异相反应在真实大气中不可避免地会相互影响。在这项研究中，通过使用 298 K 的漫反射红外光谱 (DRIFTS) 研究了在模拟太阳辐射不存在和存在的情况下，NO2 的异质吸收对颗粒表面乙醛转化的影响。在没有模拟太阳辐射的情况下，NO2 的预吸附在短时间内促进了水合反应和随后的多聚低聚反应以及 CH3CHO 的低聚反应，但这些反应受到显着阻碍，伴随着较长时间的 NO2 预吸附，巴豆醛和乙酸盐的形成略有增强。在模拟太阳辐照下，光照、氢键（H-键）催化、表面酸性增强和亚硝酸盐和硝酸盐形成的综合作用促进了羟醛缩合和CH3CHO氧化的发生，尤其是，形成的亚硝酸盐和硝酸盐的光解，而水合反应和随后的多聚反应以及 CH3CHO 分子的低聚反应受到抑制。同时，光照射显着增强了羟醛缩合的氢键催化作用，显示出氢键催化和光照相结合的结果。提出了非均相反应机理，