超稳Y型分子筛B酸中心可接近性的研究

石油炼制与化工 ›› 2020, Vol. 51 ›› Issue (8): 70-75.

超稳Y型分子筛B酸中心可接近性的研究

孔维杰,王焕,张晓彤,宋丽娟

辽宁石油化工大学辽宁省石油化工催化科学与技术重点实验室

收稿日期:2020-02-18 修回日期:2020-03-31 出版日期:2020-08-12 发布日期:2020-08-27
通讯作者: 宋丽娟 E-mail:lsong56@263.net; lsong@lnpu.edu.cn
基金资助:
多级孔分子筛孔隙结构与扩散性能关联性的频率响应法研究;多级复合孔材料纳微尺度内传质性能及催化活性中心可接近性的研究;基于调控传质性能的多产丙烯FCC催化剂设计新策略

ACCESSIBILITY STUDY OF BRONSTED ACID SITE IN USY ZEOLITE

Received:2020-02-18 Revised:2020-03-31 Online:2020-08-12 Published:2020-08-27
Supported by:

摘要/Abstract

摘要： 超稳Y分子筛B酸中心可接近性是影响其催化裂化性能的关键因素，选取超稳Y分子筛（USY）和常规HY分子筛进行对比，结合晶格结构和孔结构表征参数，采用原位红外光谱技术以3种不同尺寸的探针分子（吡啶、2,6-二甲基吡啶、2,6-二叔丁基吡啶）对两种分子筛的酸中心可接近性进行对比，并以大港轻柴油为原料进行催化裂化微反活性评价。结果表明：USY分子筛的超笼内B酸中心对较大尺寸探针的可接近性明显优于常规HY分子筛，并推断较低的B酸密度是USY分子筛表现出更高超笼内B酸中心可接近性的主要原因；USY分子筛的微反活性为69%，明显高于常规HY分子筛。

关键词: 超稳Y分子筛, B酸中心, 超笼, 可接近性, 原位红外光谱

Abstract: The accessibility of the Bronsted acid center of the USY is the key factor to catalytic cracking performance. The physical properties and structural parameters of USY and HY zeolites were investigated by in-situ infrared specrum technique using pyridine, 2, 6-dimethylpyridine, and 2,6-di-tert-butylpyridine as probe molecules. The MAT evaluation was conducted using Dagang light diesel fraction as feed. It was found that the accessibility of the Bronsted acid sites in the supercages of the USY zeolite to the larger-sized probes is significantly better than that of the conventional HY zeolite. It was concluded that lower Bronsted acid density is the main reason that USY zeolite showed superior Bronsted acid center accessibility in the cage. The MAT of USY zeolite was 69%, higher than that of conventional HY zeolite.

Key words: USY zeolite, Bronsted acid site, supercage, accessibility, in-situ infrared spectrum

中图分类号:

孔维杰王焕张晓彤宋丽娟. 超稳Y型分子筛B酸中心可接近性的研究[J]. 石油炼制与化工, 2020, 51(8): 70-75.

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