La修饰ZSM-5分子筛催化剂用于C_4烯烃催化裂解制丙烯  

ZSM-5 catalysts modified with lanthanum for catalytic cracking of C_4-olefins to propylene

作　　者：任丽萍[1] 赵国良[1] 滕加伟[1] 王仰东[1] 谢在库[1] 

机构地区：[1]中国石化上海石油化工研究院,上海201208

出　　处：《工业催化》2007年第3期30-34,共5页Industrial Catalysis

基　　金：国家重点基础研究发展计划(973计划)项目(2003CB615804);上海市科委科研资助项目(03DJ14004)

摘　　要：采用不同含量的La对ZSM-5分子筛进行改性,考察其在C4烯烃催化裂解制丙烯反应中的催化性能。结果发现,少量La的引入不会破坏分子筛催化剂的骨架结构,改性后催化剂活性的变化是由于其表面酸性的改变而引起。分子筛催化剂表面酸量决定其C4烯烃裂解反应活性,La的加入使催化剂表面酸量减少,从而使烯烃转化率降低。催化剂表面酸强度是影响其产物分布的主要因素,酸性越强,催化剂裂解能力越强,产物丙烯的选择性也就越高。尽可能提高催化剂表面强酸的酸量是C4烯烃催化裂解制丙烯反应催化剂的研制方向。ZSM-5 zeolite was modified with different content of lanthanum and used as the catalyst for C4-olefins cracking to propylene. It was found that doping of small quantity of lanthanum would not affect framework structure of ZSM-5, and enhancement of the catalytic activity was due to the changes in acidity of surface of the catalyst. Activity for C4-olefins cracking was dependent on acid sites on the catalyst, which was brought down by lanthanum modification and thus decreased C4-olefin conversion. Acidity of surface of the catalyst as the main influential factor for product distribution. The stronger the acid sites, the higher the cracking activity, and the higher the selectivity to propylene. Enhancement of the quantity of strong acid sites is the trend in development of C4-olefins cracking catalysts.

关 键 词：ZSM-5分子筛 C4烯烃 催化裂解 丙烯 酸性 

分 类 号：TE624.95[石油与天然气工程—油气加工工程] TQ426.95[化学工程]