改性H-ZSM-34上氯甲烷催化转化制低碳烯烃(英文)  

Catalytic conversion of methyl chloride to lower olefins over modified H-ZSM-34

作　　者：徐霆[1] 宋航[1] 邓卫平[1] 张庆红[1] 王野[1] 

机构地区：[1]厦门大学化学化工学院能源材料化学协同创新中心固体表面物理化学国家重点实验室/醇醚酯化工清洁生产国家工程实验室,福建厦门361005

出　　处：《催化学报》2013年第11期2047-2056,共10页

基　　金：supported by the National Basic Research Program of China (2010CB732303);the National Natural Science Foundation of China (21173174, 20923004, 21033006, and 21161130522);the Program for Changjiang Scholars and Innovative Research Team in University (IRT1036)~~

摘　　要：比较了几种典型的沸石分子筛在氯甲烷转化制乙烯、丙烯和丁烯等低碳烯烃反应中的催化性能,发现H-ZSM-34具有较佳的催化活性和选择性.经乙二胺四乙酸二钠(Na2H2EDTA)水溶液处理,并经离子交换及焙烧后,H-ZSM-34上氯甲烷转化制低碳烯烃的催化性能显著改善.当Na2H2EDTA浓度为0.1 mol/L,反应温度为673 K,CH3Cl分压9.2 kPa时,C2–C4烯烃选择性和收率分别达82%和61%.研究还发现,Ce修饰H-ZSM-34催化剂同样可改善氯甲烷制低碳烯烃的选择性和收率.表征结果表明,Na2H2EDTA处理和Ce修饰均降低了H-ZSM-34的酸性.酸性的降低可抑制低碳烯烃的氢转移反应,继而避免了其进一步转化为低碳烷烃.Among several typical zeolites,H-ZSM-34 was found to be an efficient catalyst for the conversion of methyl chloride to lower olefins,i.e.,ethylene,propylene,and butenes.Treatment of H-ZSM-34 with a Na2 H2 EDTA(EDTA = ethylenediaminetetraacetate) aqueous solution followed by ion exchange and calcination enhanced the catalytic performance significantly.The selectivity to lower olefins increased significantly for certain Na2 H2 EDTA aqueous solution concentrations;when the H-ZSM-34 catalyst was treated with a 0.1 mol/L Na2 H2 EDTA solution,the selectivity and yield of C2 –C4 olefins reached 82% and 61%,respectively,at 673 K and a CH3 Cl partial pressure of 9.2 kPa.The modifica- tion of H-ZSM-34 with Ce ions improved C2 –C4 olefin selectivity and yield.Catalyst characterization suggests that treatment with Na2 H2 EDTA or modification by Ce decreases the acidity of H-ZSM-34. The weakened acidity of the treated or modified H-ZSM-34 may suppress the hydrogen transfer reaction and prevent lower olefins from further transformation to paraffins.

关 键 词：氯甲烷 低碳烯烃 H-ZSM-34 乙二胺四乙酸二钠处理 铈修饰 酸性 

分 类 号：O643.32[理学—物理化学]