无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2024, Vol. 56 ›› Issue (1): 134-140.doi: 10.19964/j.issn.1006-4990.2023-0183

• 催化材料 • 上一篇    下一篇

多级孔纳米SAPO-34分子筛制备及甲醇制烯烃性能研究

陈旭(), 杨刚(), 李海涛   

  1. 南京工业大学化工学院,材料化学工程国家重点实验室,江苏 南京 211800
  • 收稿日期:2023-03-31 出版日期:2024-01-10 发布日期:2024-01-18
  • 通讯作者: 杨刚,男,博士,教授;E-mail:yanggang@njtech.edu.cn
  • 作者简介:陈旭(1997— ),男,硕士,研究方向为催化剂制备及应用;E-mail:751391627@qq.com
  • 基金资助:
    国家科技支撑计划项目(2013BAE11B03);江苏省产学研前瞻性联合研究项目(BY2016005-11)

Study on preparation of multistage pore nano-SAPO-34 molecular sieves and its methanol to olefin performance

CHEN Xu(), YANG Gang(), LI Haitao   

  1. State Key Laboratory of Materials-Oriented Chemical Engineering,College of Chemical Engineering,Nanjing Tech University,Nanjing 211800,China
  • Received:2023-03-31 Published:2024-01-10 Online:2024-01-18

摘要:

为缩短SAPO-34分子筛的高温晶化时间,提高其在甲醇制烯烃(MTO)反应中的寿命和选择性,以三乙胺和四乙基氢氧化铵作为双模板剂,采用分步晶化法快速制备了粒径为300~500 nm的纳米SAPO-34分子筛,同时添加表面活性剂十六烷基三甲基溴化铵(CTAB)进一步对分子筛进行改性,得到多级孔纳米SAPO-34分子筛(C-ST1T2)。对制备的所有样品进行理化性质表征,并应用于甲醇制烯烃的催化反应,考察了其在一定条件下的催化性能。表征结果显示,分步晶化法可以有效缩短分子筛的晶化时间,并且得到纳米级SAPO-34分子筛。用CTAB改性后得到的多级孔纳米SAPO-34分子筛晶型完整,具有多级孔道结构和适中的酸强度。催化性能测试表明,C-ST1T2的甲醇转化率能够达到100%,并且催化寿命可以达到690 min,较单模板剂合成的分子筛有较大提升,同时低碳烯烃的选择性稳定在89%以上。研究结果表明,利用CTAB对纳米分子筛的多级孔改性,有利于分子筛的MTO反应性能进一步提升。

关键词: SAPO-34, 纳米分子筛, 分步晶化, MTO反应

Abstract:

In order to shorten the crystallization time of SAPO-34 molecular sieve at high temperature and improve its life and selectivity in MTO reaction,triethylamine and tetraethyl ammonium hydroxide were used as double templates to rapidly prepare nano-sized SAPO-34 molecular sieve with a particle size of 300~500 nm by step crystallization method.At the same time,the surfactant cetyltrimethyl ammonium bromide(CTAB) was added to further modify the molecular sieve,and the multiporous SAPO-34 molecular sieve(C-ST1T2) was obtained.The physicochemical properties of all the samples were characterized and applied to the catalytic reaction of methanol to olefin.The catalytic performance under certain conditions was investigated.The characterization results showed that the crystallization time of nano-sized SAPO-34 molecular sieve could be shortened by step crystallization.After modification by CTAB,SAPO-34 molecular sieve with multistage pore structure and moderate acid strength was obtained.The catalytic performance test showed that the methanol conversion rate of C-ST1T2 could reach 100%,and the catalytic life could reach 690 min,which was significantly improved compared with the molecular sieve synthesized by single template agent.Meanwhile,the selectivity of low carbon olefin was stable at more than 89%.The results showed that the multistage pore modification of molecular sieve using CTAB was beneficial to further improve the MTO reaction performance of molecular sieve.

Key words: SAPO-34, nano molecular sieves, step-by-step crystallization, MTO reaction

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