The manufacture of 1,1-dichloroethylene（1,1-DCE） usually employs liquid phase method to perform the dehydrochlorination of 1,1,2-trichloroethane（TCE）, where large amounts of high-concentration salty wastewater is ...The manufacture of 1,1-dichloroethylene（1,1-DCE） usually employs liquid phase method to perform the dehydrochlorination of 1,1,2-trichloroethane（TCE）, where large amounts of high-concentration salty wastewater is produced inevitably. It has been a long-term goal to achieve the gas phase synthesis of 1,1-DCE via supported cata- lysts. In this work, the gas-phase synthesis of 1,1-DCE from TCE was studied in the presence of pentaethylenehexamine（PEHA） supported on silica. High and stable selectivity to 1,1-DCE（up to 98%） was obtained, which could be ascribed to the relatively strong basicity of PEHA according to a proposed E2 mechanism. The formation of PEHA chloride from the HCI generated in situ was detected and was considered to be the main reason for the deactivation of PEHA catalyst.展开更多
基金Supported by the National Natural Science Foundation of China（No.NSFC-21476207）, and the Open Research Fund of Top Key Discipline of Chemistry in Zhej iang Provincial Colleges（Zhej iang Normal University）, China（No.ZJHX201413 ）.
文摘The manufacture of 1,1-dichloroethylene（1,1-DCE） usually employs liquid phase method to perform the dehydrochlorination of 1,1,2-trichloroethane（TCE）, where large amounts of high-concentration salty wastewater is produced inevitably. It has been a long-term goal to achieve the gas phase synthesis of 1,1-DCE via supported cata- lysts. In this work, the gas-phase synthesis of 1,1-DCE from TCE was studied in the presence of pentaethylenehexamine（PEHA） supported on silica. High and stable selectivity to 1,1-DCE（up to 98%） was obtained, which could be ascribed to the relatively strong basicity of PEHA according to a proposed E2 mechanism. The formation of PEHA chloride from the HCI generated in situ was detected and was considered to be the main reason for the deactivation of PEHA catalyst.
