表面活性剂-模板化法制备多级孔β沸石及其四氢萘加氢裂化制苯、甲苯、二甲苯的催化性能  

Hierarchical β Zeolite by Surfactant-Templating Method: Preparation and Catalytic Performance in Tetralin Hydrocracking to Benzene, Toluene, and Xylene

作　　者：张燕挺 党辉 张妮妮 陈胜利[1] ZHANG Yan-Ting;DANG Hui;ZHANG Ni-Ni;CHEN Sheng-Li(State Key Laboratory of Heavy Oil Processing,China University of Petroleum,Beijing 102249,China)

机构地区：[1]中国石油大学(北京)重质油国家重点实验室,北京102249

出　　处：《无机化学学报》2022年第7期1350-1360,共11页Chinese Journal of Inorganic Chemistry

摘　　要：采用表面活性剂-模板化法,分别以β-60和β-150为母体,选用十六烷基三甲基溴化铵(CTAB)作为表面活性剂,以一步和两步法制备了2种多级孔β沸石。以X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、N_(2)吸附-脱附测试和NH_(3)程序升温脱附(NH_(3)-TPD)测试对多级孔β沸石的物化性质进行分析。采用等体积浸渍法负载25%的WO_(3)制备成加氢裂化催化剂,考察其在四氢萘加氢裂化制备苯(B)、甲苯(T)和二甲苯(X)的催化性能。结果表明:相比于母体,一步制备样品的介孔孔容提高3倍以上,两步制备样品的介孔孔容提高1倍以上。另外,以β-60为母体,一步和两步制备样品的介孔均是无序的。一步制备样品的最高BTX收率是53%,两步制备样品的最高BTX收率是51%;然而,以β-150为母体,一步制备样品的介孔是无序的,而两步制备样品的介孔是有序的。一步制备样品的最高BTX收率是46%,两步制备样品的最高BTX收率是50%。因此,多级孔β沸石制备的加氢裂化催化剂的催化性能是由介孔的含量和有序度共同决定的。In this study, a series of hierarchical β zeolites were prepared from the parent zeolites(β-60 and β-150)by one/two-step surfactant-templating method with cetyltrimethylammonium bromide(CTAB) as the surfactant. The physicochemical properties of the hierarchical β zeolites were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), N_(2) adsorption-desorption test, and NH_(3) temperature-programmed desorption(NH_(3)-TPD) test. The results show that the mesopore volume of the hierarchicalβ zeolites prepared in one step was increased by more than 3 times, and the mesopore volume of hierarchical βzeolites prepared in two steps was increased by more than 1 time compared with the parent zeolite. Furthermore, the hydrocracking catalysts were prepared by loading WO_(3) onto these hierarchical β zeolites, and their catalytic performance in the hydrocracking of tetralin to benzene(B), toluene(T), and xylene(X) was investigated. Taking β-60 as the parent zeolite, the mesopores of the hierarchically porous β zeolite obtained after one-step or two-step treatment were both disordered, and BTX yields reached 53% and 51%, respectively. However, taking β-150 as the parent zeolite, the mesopores of the hierarchical β zeolites prepared by the one-step method were disordered, while the mesopores of the samples prepared by the two-step method were ordered. The highest yield of BTX prepared by the onestep method was 46%, and that prepared by the two-step method was 50%. Therefore, the catalytic performance of hydrocracking catalyst prepared from hierarchical β zeolites was determined by the mesopore content and degree of order.

关 键 词：Β沸石 多级孔 表面活性剂 加氢裂化 

分 类 号：TQ624.4[化学工程—精细化工]