ZSM-35分子筛酸性对正丁烯异构化性能的影响

石油炼制与化工 ›› 2020, Vol. 51 ›› Issue (8): 56-61.

ZSM-35分子筛酸性对正丁烯异构化性能的影响

刘晓华,黄文氢,满毅,宋建会,柳颖

中国石化北京化工研究院

收稿日期:2020-03-03 修回日期:2020-03-27 出版日期:2020-08-12 发布日期:2020-08-27
通讯作者: 黄文氢 E-mail:huangwq.bjhy@sinopec.com
基金资助:

ACIDITY OF ZSM-35 ZEOLITE AND EFFECT ON N-BUTENE ISOMERIZATION

Received:2020-03-03 Revised:2020-03-27 Online:2020-08-12 Published:2020-08-27
Supported by:

摘要/Abstract

摘要： 为了详尽定性和定量分析ZSM-35分子筛孔道内部和外部的酸中心，对在不同焙烧晶化条件下制备的3种ZSM-35分子筛样品（编号分别为GNJ，GNX，GW）采用NH3-TPD和吸附不同探针分子的31P MAS NMR谱进行表征，并在微反装置上对3种样品进行催化正丁烯异构化反应性能评价。结果表明：ZSM-35分子筛中Bronsted酸酸量远多于Lewis酸酸量，且不同制备方法得到的ZSM-35分子筛Bronsted酸强度与酸量不同；GNJ主要有1种弱Bronsted酸中心，GW有3种不同强度的Bronsted酸中心，较弱的Bronsted酸中心在孔道内部和外部均有分布，较强的两种Bronsted酸中心主要分布在孔道内部；GNX有两种不同强度的Bronsted酸中心，在孔道内部和外部均有分布，且GNX的Bronsted酸酸量高于GNJ和GW；催化正丁烯异构化反应时，ZSM-35分子筛的中强Bronsted酸中心是异丁烯生成的必要酸中心，且中强Bronsted酸中心更有利于异丁烯的生成，因此制备具有合适的中强Bronsted酸强度和酸分布的ZSM-35分子筛有利于正丁烯异构化反应的进行。

关键词: ZSM-35分子筛, 异构化, 酸性, 固体核磁共振技术, 探针分子

Abstract: In order to determine qualitatively and quantitatively the internal and external acid sites of ZSM-35 zeolites, three types of ZSM-35 samples (GNJ, GNX, and GW) prepared under different crystallization and calcination conditions were characterized using NH3-TPD and 31P MAS NMR with different probe molecules. The selectivity and activity of n-butene isomerization of different catalysts were investigated. The results showed that the amount of Bronsted acid site in ZSM-35 zeolites were much more than Lewis acid site, the acid strength and amount on ZSM-5 zeolite were different according to preparation conditions. GNJ had a kind of weak Bronsted acid site, GW had three kinds of Bronsted acid sites with different strengths, the weaker Bronsted acid sites were distributed inside and outside the channel and the stronger two kinds of Bronsted acid sites were mainly distributed inside the channel. GNX had two kinds of Bronsted acid sites of different strengths and distributed inside and outside the channel. Bronsted acid amount of GNX was more than the other two samples. It is recognized that the medium strong Bronsted acid was an essential for isobutene formation. Therefore, the ZSM-35 molecular sieve with appropriate suitable medium-strong Bronsted acid and distribution was beneficial to the n-butene isomerization reaction.

Key words: ZSM-35 zeolite, isomerization, acidity, solid-state nuclear magnetic resonance, probe molecule

中图分类号:

刘晓华黄文氢满毅宋建会柳颖. ZSM-35分子筛酸性对正丁烯异构化性能的影响[J]. 石油炼制与化工, 2020, 51(8): 56-61.

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