两段变温法水热合成多级孔ZSM-5分子筛及其催化裂化性能（英文）  

Synthesis of Hierarchical ZSM-5 Zeolites via Two Stage Varying Temperature Crystallization with Enhanced Catalytic Cracking Performance

作　　者：王有和 孙洪满 彭鹏 白鹏 阎子峰 Subhan Fazle 季生福[1] WANG You-He;SUN Hong-Man;PENG Peng;BAI Peng;YAN Zi-Feng;JI Sheng-Fu

机构地区：[1]北京化工大学化工资源有效利用国家重点实验室,北京100029 [2]中国石油大学重质油国家重点实验室,青岛266580 [3]赫尔大学工程与计算机学院,英国赫尔HU67RX [4]阿普杜勒瓦利汉大学化学系,巴基斯坦马尔丹

出　　处：《无机化学学报》2018年第5期989-996,共8页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.21776311)、中央高校基本科研业务费专项资金(No.15CX05030A)和应用表面与胶体化学教育部重点实验室(陕西师范大学)开放课题基金(No.2017026)资助项目。

摘　　要：以四丙基氢氧化铵(TPAOH)为单一模板剂,采用低温老化、高温晶化2段变温法合成出了球状多级孔ZSM-5分子筛。利用XRD、FT-IR、NH_3-TPD、SEM、TEM以及氮气吸-脱附等测试对合成样品进行了表征。结果表明:直径约为2μm左右的球状多级孔ZSM-5分子筛颗粒内的晶间介孔和大孔主要由棒状纳米晶堆积而成的,该产品具有较大的比表面积和介孔孔容。同常规水热法一步合成的微孔ZSM-5分子筛相比,2段变温法合成的多级孔ZSM-5分子筛具有更高的B酸/L酸比例(C_(BP)/C_(LP))、强酸/弱酸比例(C_s/C_w)以及活性位可接近性指数(ACI)。催化裂化评价结果显示,得益于活性位可接近性指数等指标的提高,球状多级孔ZSM-5分子筛比常规合成的微孔ZSM-5分子筛具有更高的转化率和丙烯收率等优异的催化性能。Hierarchical ZSM-5 zeolites with regular spherical structure were successfully synthesized via a facile two stage varying temperature crystallization using tetrapropylammonium hydroxide(TPAOH)as the single template.The fabricated samples were characterized by means of XRD,FT-IR,NH3-TPD,SEM,TEM and N2 adsorption-desorption isotherms.The results indicate that the spherical ZSM-5 zeolite particles with around 2μm in diameter possess intercrystalline meso-and macropores generated from the aggregation of bar-shape ZSM-5 nanocrystals,which exhibit large specific surface area and mesopore volume.Compared to the ZSM-5 zeolite synthesized by constant temperature hydrothermal method,the hierarchical ZSM-5 zeolites have higher Bronsted acid to Lewis acid ratio(CBP/CLP)and strong acid to weak acid ratio(Cs/Cw),as well as the enhanced accessibility of the active sites,which were very important to the catalytic reaction.Catalytic tests reveal that hierarchical ZSM-5-contained catalytic cracking catalyst exhibit an outstanding performance in improving the propylene yield and conversion due to the enhancement of accessibility.

关 键 词：多级孔ZSM-5分子筛 两段变温法 单一模板剂 球状结构 催化裂化 

分 类 号：O611.4[理学—无机化学]