硅铝比对HZSM-5分子筛催化正丁烷裂解反应性能的影响  

EFFECTS OF SiO_2/Al_2O_3 RATIO OF HZSM-5 ZEOLITES ON n-BUTANE CRACKING

作　　者：张文芳[1] 王鹏照 张敏秀[1] 杨朝合[1] 李春义[1] Zhang Wenfang;Wang Pengzhao;Zhang Minxiu;Yang Chaohe;Li Chunyi(State Key Laboratory of Heavy Oil Processing,China University of Petroleum(East China),Qingdao,Shandong 266580;National Engineering Research Center of Chemical Fertilizer Catalyst,Fuzhou University)

机构地区：[1]中国石油大学(华东)重质油国家重点实验室,山东青岛266580 [2]福州大学化肥催化剂国家工程研究中心

出　　处：《石油炼制与化工》2019年第3期48-53,共6页Petroleum Processing and Petrochemicals

基　　金：中国石油大学(华东)研究生自主创新工程基金项目(YCX2018036)

摘　　要：利用原位红外光谱法对不同硅铝比的HZSM-5分子筛催化剂进行表征,并在微反评价装置上对不同硅铝比分子筛催化正丁烷高温裂解活性进行评价,揭示了HZSM-5分子筛"硅铝比-活性位性质-催化性能"三者之间的关系。结果表明,硅铝比[n(SiO_2)/n(Al_2O_3)]分别为38和200的HZSM-5分子筛表面活性位类型、数目和强度均存在巨大差异。HZSM-5-38分子筛表面存在较多的强酸性的硅铝桥键羟基和非骨架铝羟基,而HZSM-5-200分子筛表面仅存在少量的弱酸性或不具酸性的微孔内邻位孤立硅羟基和外表面孤立硅羟基。HZSM-5-200分子筛表现出更高的低碳烯烃收率,因而较低的酸密度和酸强度有利于多产烯烃。The HZSM-5 zeolites with different mole ratio of SiO2/Al2O3 were characterized by in-situ FT-IR and their n-butane cracking activities were investigated in a continuous flow fixed-bed micro-reactor to reveal the relationship between Si/Al ratio,active sites and catalytic behavior.The results indicated that the kind,number,and strength of active sites of HZSM-5 zeolites with Si/Al ratio of 38 and 200 were significantly different.HZSM-5-38 zeolites have more acid bridging Si-O(H)-Al groups and non-skeleton aluminum hydroxyl with strong acidity,while,HZSM-5-200 zeolites only show several isolated hydroxyl groups with small amount of weakly acidic or non-acidic neighbouring silica hydroxyl groups in microporous.HZSM-5-200 zeolites result in higher yield of light olefins,indicating that lower acid density and strength is suitable for producing more olefins.

关 键 词：HZSM-5 活性位 原位红外光谱法 裂解 

分 类 号：O643.36[理学—物理化学] O623.12[理学—化学]