ZSM-5/丝光沸石混晶分子筛的合成、表征及性能研究

SYNTHESIS, CHARCTERIZATION AND CATALYTIC PROPERTY OF THE CO-CRYSTALLINE ZEOLITE OF ZSM-5 AND MORDENITE

采用水热晶化法直接合成了ZSM-5/丝光沸石混晶分子筛。采用X射线衍射仪、X射线荧光谱仪、扫描电子显微镜、红外光度仪、吸附仪等对其结构进行了表征,还在脉冲微反和轻瓦斯油微反上评价了其裂化、异构化活性。结果表明,混晶分子筛适宜的合成条件:物料组成n(Al2O3):n(SiO2):n(H2O)为1:(20-50):(700-2000),pH为11.5-13,反应温度(T)175℃,反应时间(t)60-96 h;混晶分子筛和ZSM-5与丝光沸石的机械混合分子筛在形貌和微观结构上有差别,混晶分子筛的裂化、异构化活性优于机械混合分子筛。

The co-crystalline zeolite of ZSM-5 and mordenite was directly crystallized synthesized by varying SiO2/Al2O3 molar ratio and pH value in the hydrothermal synthesis system. The favorable synthetic conditions for the co-crystalline zeolite were n(Al2O3) : n(SiO2) : n(H2O)= 1 : (20 - 50) : (700-2000); pH value of 11. 5 - 13; reaction temperature of 175℃ and reaction time of 60-96 h. The product co-crystalline zeolite was characterized by XRD, SEM and IR. The co-crystalline was found consisting of two kinds of zeolite structure: ZSM-5 and mordenite. The cracking activity of the co-crystalline zeolite was studied with pure hydrocarbons as the feedstock in a pulse micro reactor and in a continuous micro fixed bed reactor with light gas oil as the feedstock. The co-crystalline zeolite showed higher cracking, isornerization catalytic activity than that of the physical mixture of ZSM-5 and mordenite.