超细颗粒物为大气中痕量气态污染物转化提供了广泛的反应界面,在其表面发生多相界面反应是大气二次颗粒物形成的主要途径。含铁超细颗粒是大气气溶胶的主要成分之一。本研究采用同步辐射X射线近边吸收谱(X-ray Absorption Near Edge Str...超细颗粒物为大气中痕量气态污染物转化提供了广泛的反应界面,在其表面发生多相界面反应是大气二次颗粒物形成的主要途径。含铁超细颗粒是大气气溶胶的主要成分之一。本研究采用同步辐射X射线近边吸收谱(X-ray Absorption Near Edge Structure,XANES)技术开展了Fe_3O_4超细颗粒表面的多相反应研究,分析了反应时间、紫外照射及臭氧存在条件对二次颗粒物形成的影响。研究发现:SO_2在Fe_3O_4超细颗粒表面能被快速氧化形成硫酸根(SO_4^(2-)),其中紫外光照(Ultra-Violet,UV)和O_3可以促进硫酸根的生成。从反应时间上看,SO_2在Fe_3O_4超细颗粒表面可快速反应生成高价态硫酸根,30 min时,约99%的硫化物转化成硫酸根。通过对S的XANES谱进行一阶导数处理,发现产物中还存在亚硫酸根(SO_3^(2-))的峰,提示SO_2在Fe_3O_4颗粒物表面可先生成亚硫酸根,进而被快速氧化成硫酸根。展开更多
The program Chemkin was used to investigate effect mechanism of existence patterns of sulfur on reduction of NO under poor oxygen condition.Three factors such as combustion of hydrocarbon,formation of NOx and interact...The program Chemkin was used to investigate effect mechanism of existence patterns of sulfur on reduction of NO under poor oxygen condition.Three factors such as combustion of hydrocarbon,formation of NOx and interaction between sulfur and nitrogen were considered.The results show that reaction of HCN oxidation to NO finishes in milliseconds,whereas the reduction process of NO is gentle,finishing in seconds.SH and SN are important matters for direct reduction of NO under poor oxygen conditions.The reaction between SH and NO is intense,because concentration of SH increases after addition of SO2.As a result concentration of NO decreases.Therefore,existence patterns of sulfur can promote reduction of NO effectively under poor oxygen condition.展开更多
文摘The program Chemkin was used to investigate effect mechanism of existence patterns of sulfur on reduction of NO under poor oxygen condition.Three factors such as combustion of hydrocarbon,formation of NOx and interaction between sulfur and nitrogen were considered.The results show that reaction of HCN oxidation to NO finishes in milliseconds,whereas the reduction process of NO is gentle,finishing in seconds.SH and SN are important matters for direct reduction of NO under poor oxygen conditions.The reaction between SH and NO is intense,because concentration of SH increases after addition of SO2.As a result concentration of NO decreases.Therefore,existence patterns of sulfur can promote reduction of NO effectively under poor oxygen condition.
