合成CuHZSM-5沸石的结构、酸性和催化性质  

THE STRUCTURE, ACIDITY AND CATALYTIC PROPERTY OF SYNTHESIZED CuHZSM-5 ZEOLITE

作　　者：张迪倡[1] 舒兴田[1] 左丽华[1] 杜崇敬[1] 何鸣元[1] 

机构地区：[1]石油化工科学研究院

出　　处：《石油学报（石油加工）》1992年第2期52-59,共8页Acta Petrolei Sinica(Petroleum Processing Section)

摘　　要：本工作以铜盐为晶种合成出CuZSM-5沸石,制成了CuHZSM-5沸石(简称CuHZSM-5(合));用X射线衍射、尺码分子吸附、氮吸附微量量热、热分析系统(DSC、TGA、DTA)以及混合烃连续微反、临氢和非临氢纯烃脉冲微反等技术,考察了样品的结构、酸性、择形性能和催化裂化活性,并与H型、Cu^(2+)交换型的ZSM-5沸石进行了比较。实验结果表明,CuHZSM-5(合)确系一种含铜高硅铝比ZSM-5晶型沸石,Cu^(2+)离子有可能进入沸石的阳离子位置,从而使孔道结构变窄,显示出良好的择形性能;在高温条件下对沸石的酸性中心起着保护作用;对氨有多种吸附中心;在临氢条件下,有较高的酸性裂解活性。CuHZSM-5 zeolite was directly synthesized by using copper salts as crystalline seed. The prepared zeolite was ion-exchanged with NH_4^+, followed by calcination. The product is designated as CuHZSM-5 (synthesized). The structure, acidity, shape selectivity and the cracking activity of the zeolite thus obtained were examined by means of X-ray diffraction, hydrocarbon adsorption, microcalorimetry of ammonia adsorption, thermal analysis and reaction activity tests. The results were compared with those of HZSM-5 and CuHZSM-5 prepared by ion-exchange method. The synthesized CuHZSM-5 zeolite displays a characteristic XRD pattern identical to pentasil type zeolite. The copper ions in synthesized CuHZSM-5 seem to be located on cation sites in the zeolite channel and thus make the channel narrower. This zeolite has better shape selectivity in n-hexane and cyclohexane adsorption. The results show that the copper ion in synthesized CuHZSM-5 may have a role to maintain the associated acid sites at high temperature and to provide more active sites for ammonia adsorption, and thus making the zeolite to display higher hydrocracking activity in flowing hydrogen.

关 键 词：结构 酸性 催化性质 合成沸石 

分 类 号：TQ424.25[化学工程]