【摘要】 碳酸钙 (CaCO3 )是大气中矿物颗粒物的重要组分 ,其非均相大气化学行为很不清楚。利用原位漫反射红外傅里叶变换光谱 (DiffuseReflectanceInfraredFourierTransformSpectroscopy ,DRIFTS)研究了二氧化硫(SO2 )在CaCO3 颗粒物表面的转化情况。通过比较不同条件下 ,亚硫酸盐和硫酸盐的原位光谱 ,探讨了SO2在CaCO3 表面氧化中臭氧 (O3 )所起的作用。结果表明 ,利用DRIFTS原位分析反应器研究CaCO3 表面硫酸盐的生成是可行的。在存在O3 条件下 ,SO2 在CaCO3 表面能够被氧化成硫酸盐 ,反应分为吸附和氧化两个步骤进行。更多还原

【Abstract】 CaCO 3 is an important component of mineral dust aerosols in the atmosphere, but its role in atmospheric heterogeneous chemistry is still unclear. In this paper, the oxidation of SO 2 on CaCO 3 particles was studied using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Formation of sulfite and sulfate was identified on the surface, and the role of O 3 on the oxidation process is determined by comparing the experiments in different conditions. DRIFTS is proved as a useful tool for studying heterogeneous reactions on CaCO 3 particles. The results show that in the presence of O 3, SO 2 can be oxidized into sulfate on the surface of CaCO 3 particles. A two-step mechanism that involves adsorption of SO 2 followed by oxidation is presented.更多还原