Hierarchical SAPO-11 Molecular Sieve for n-Alkane Hydroisomerization Synthesized by Directing Agent Method

• 作者: Meng Yuan Wang Haiyan Sun Na Yang Zhanxu Wang Yujia
• 来源期刊: 中国炼油与石油化工（英文版）
• 年，卷（期）: 2020,（4）
• 所属期刊栏目: Catalyst Research
• 页码范围: 85-92
• 页数: 8页
• 语种: 英文

摘要

Silicoaluminophosphates SAPO-11 molecular sieves with small particle size and hierarchical pores were synthesized using the directing agent method.The effect of crystallization time on the particle structure,morphology,pore structure properties,and acid properties of SAPO-11 molecular sieves were investigated.Unlike the SAPO-11 molecular sieves synthesized with the conventional method,the results of XRD,SEM,BET and NH3-TPD analyses showed that the SAPO-11 molecular sieves synthesized by the directing agent method in a shorter crystallization time exhibited fine and uniform morphology.By increasing the crystallization time,the particle size of SAPO-11 molecular sieve was significantly reduced,and the mesoporous structure(intercrystalline pores)was formed.Furthermore,the external specific surface area and the total specific surface area reached 81.7 m2/gand 192.0 m2/g,respectively,which effectively reduced the pore mass transfer resistance and significantly increased the number of acid sites.The results of n-dodecane hydroisomerization revealed that the Pt/SAPO-11 prepared with the novel method exhibited higher catalytic activity and better hydroisomerization selectivity than that synthesized by the conventional hydrothermal method.Thus,the small particle molecular sieve showed a promising industrial application prospect to be used as catalyst support.