双金属改性ZSM-5/L复合分子筛的制备及其催化芳构化反应性能  

SYNTHESIS OF BIMETAL ZSM-5/L COMPOSITE ZEOLITE AND ITS CATALYTIC PERFORMANCE FOR AROMATIZATION REACTION

作　　者：张若杰[1] 万海[1,2,3] 张乐[1,2] 宋丽娟[1,2] 

机构地区：[1]辽宁石油化工大学辽宁省石油化工催化科学与技术重点实验室,辽宁抚顺113001 [2]中国石油大学(华东)化学工程学院 [3]中国石油抚顺石化公司石油三厂

出　　处：《石油炼制与化工》2015年第7期67-72,共6页Petroleum Processing and Petrochemicals

基　　金：国家自然科学基金项目(20976077;21076100);国家重点基础研究发展规划(973)项目(2007CB216403);中国石油天然气股份有限公司合同项目(10-01A-01-01-01)

摘　　要：采用分级改性的方法制备Zn-ZSM-5/Pt-L核壳型双金属催化剂,通过改变金属负载量的组配方式对催化剂表面酸性进行调控,利用X射线衍射(XRD)、氮气吸附脱附、氨气程序升温脱附(NH3-TPD)、吡啶吸附-原位傅里叶变换红外光谱(Py-FTIR)等手段进行表征,并以正戊烷为原料对催化剂的轻烃芳构化性能进行评价。结果表明,在复合分子筛核壳结构的基础上,分级引入双金属的改性方式有效地调控了催化剂表面的酸分布以及L/B酸比例,使双金属催化剂更好地发挥L酸和B酸的协同催化作用,当Zn和Pt负载量分别为1.0%和0.6%时所表现出的催化性能最优,其正戊烷芳构化反应的转化率为99.1%、芳烃选择性达到47.2%。The core-shell composite zeolite Zn-ZSM-5/Pt-L was prepared via step-by-step modification. The surface acidity was regulated by changing the ratio of two metals. The physical and chemical properties were investigated by X-ray diffraction （XRD）, N2 adsorption-desorption, ammonia tempera- ture-programmed desorption （NH3-TPD） and in situ Py-FTIR spectroscopy. The light hydrocarbon aromatization performance of catalysts was evaluated using n-pentane as the raw material. The results exhibit that the modification of introducing active metal step-by-step effectively regulates the L/B acid ratio and distribution on the catalyst surface, which could cause more excellent synergism between B acid and L acid. At the loading of Zn and Pt metal of 1.0% and 0.6%, respectively, the catalytic performance reaches the best. The conversion rate of pentane is 99.1% and aromatic selectivity is up to 47.2%.

关 键 词：ZSM-5 L分子筛 复合分子筛 核壳型 双金属 芳构化 

分 类 号：O643.36[理学—物理化学]