CO_2气氛下负载型Cr_2O_3催化剂上乙苯脱氢制苯乙烯反应  

Ethylbenzene Dehydrogenation to Styrene in the Presence of Carbon Dioxide over Supported Chromia Catalysts

作　　者：叶兴南[1,2] 华伟明[1] 乐英红[1] 缪长喜[3] 谢在库[3] 高滋[1] 

机构地区：[1]复旦大学化学系 [2]复旦大学药学院,上海200032 [3]中国石油化工股份有限公司上海石油化工研究院

出　　处：《催化学报》2004年第7期581-585,共5页

基　　金：国家自然科学基金资助项目 ( 2 0 3 0 3 0 0 4) ;国家重点基础研究发展规划 ( 973 )资助项目 (G2 0 0 0 0 775 0 7) ;上海市重大基础研究资助项目 ( 0 3DJ14 0 0 4) ;上海市自然科学基金资助项目 ( 0 3ZR14 0 13 ) ;上海石油化工研究院资助项目

摘　　要：采用浸渍法制备了负载型Cr2 O3 /Al2 O3 和Cr2 O3 /SiO2 催化剂 ,并考察了催化剂在CO2 气氛下催化乙苯脱氢制苯乙烯反应的活性 .结果表明 ,Cr2 O3 /Al2 O3 的催化活性高于Cr2 O3 /SiO2 .这可能是由于Cr2 O3 在Al2 O3 载体表面的分散度大大高于在SiO2 表面的分散度 .催化剂的催化活性与Cr2 O3 的负载量有关 ,在w(Cr2 O3) =2 5 %时 ,Cr2 O3 /Al2 O3 的催化活性最高 .CO2 气氛对乙苯脱氢反应有明显的促进作用 ;在CO2 气氛下 ,Cr6+The chromia catalysts supported on γ Al 2O 3 and SiO 2 were prepared by impregnation method, and their catalytic activity for ethylbenzene (EB) dehydrogenation in the presence of CO 2 were investigated. The Cr 2O 3/Al 2O 3 catalyst was much more active than Cr 2O 3/SiO 2, which might be due to the much better dispersion of Cr 2O 3 on γ Al 2O 3 than that on SiO 2. The maximum ethylbenzene conversion of 59 0% over Cr 2O 3/Al 2O 3 appeared when w (Cr 2O 3)=25%, which was slightly higher than the dispersion threshold of Cr 2O 3 on γ Al 2O 3 support. The dispersed chromia species were more active than the crystalline ones. Compared with pure N 2 atmosphere, CO 2 atmosphere showed an obvious promoting effect on EB dehydrogenation. Under the same reaction conditions, the Cr 2O 3/Al 2O 3 catalyst displayed better catalytic performance than Fe 2O 3/Al 2O 3 and V/MgO catalysts. The XPS and TPR results revealed that both Cr 6+ and Cr 3+ species were present on the Cr 2O 3/Al 2O 3 catalyst, and the Cr 6+ species were probably the precursors of the active sites for EB dehydrogenation.

关 键 词：乙苯 脱氢 苯乙烯 氧化铬 氧化铝 氧化硅 负载型催化剂 二氧化碳 

分 类 号：O643[理学—物理化学]