非骨架铝形态对HY分子筛B酸强度的影响

石油炼制与化工 ›› 2018, Vol. 49 ›› Issue (11): 66-71.

非骨架铝形态对HY分子筛B酸强度的影响

郑健¹,李强¹,秦玉才¹,祖运²,宋丽娟^1,2

1. 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
2. 中国石油大学（华东）化学化工学院

收稿日期:2018-02-09 修回日期:2018-04-09 出版日期:2018-11-12 发布日期:2018-11-29
通讯作者: 宋丽娟 E-mail:zuyun1990@126.com
基金资助:
催化汽油中噻吩类硫化物在新型功能化吸附剂上的吸附行为研究

THEORETICAL STUDY OF INFLUENCE OF EXTRA-FRAMWORK ALUMINUM SPECIES ON BRONSTED ACID STRENGTH IN HY ZEOLITES

Received:2018-02-09 Revised:2018-04-09 Online:2018-11-12 Published:2018-11-29
Supported by:

摘要/Abstract

摘要： 利用周期性的密度泛函理论，研究了HY分子筛中加入[AlO]+和[Al(OH)]2+非骨架物种时对B酸强度的影响。去质子化能和氨气吸附能结果表明：[AlO]+和[Al(OH)]2+非骨架物种的加入可增强B酸强度，增强B酸强度能力[Al(OH)]2+物种强于[AlO]+物种；NH3在B酸位上吸附后会抢夺B酸的H原子变成NH4+，NH3作为给电子体系将电子转移给分子筛的B酸活性中心，B酸的酸性越强，转移的电子越多。通过几何结构参数和电子性质分析，发现非骨架物种对B酸结构的影响较小，但会影响分子筛骨架的电子结构，从而影响其酸性。

关键词: 非骨架铝, HY分子筛, B酸酸性, 密度泛函理论

Abstract: The extra-framework aluminum species on the acidity of HY molecular sieve has a major influence on the properties of modified molecular sieves. The effect of [AlO]+ and [Al(OH)]2+ extra-framework Al species on the acidity of Br?nsted acid in HY zeolites was studied by using the periodic Density Functional Theory. By analyzing the deprotonation energy and the ammonia adsorption energy, it was recognized that the [Al(OH)]2+ species can strengthen the Br?nsted acid more effectively than the [AlO]+ species. The attached ammonia molecule can grab the H atoms of Br?nsted acid and turn into NH4+ species, NH3 works as an electron donor to transfer part of the electrons to the active center of HY zeolite. The more strength of Br?nsted acid, the more electrons transferred. Through geometric and electronic analysis, it was found that the influence of extra-framework Al species on the structure of Br?nsted acid is insignificant, but affects the electron structure of the molecular sieve skeleton, thus affecting its acidity.

Key words: extra-framework aluminum, HY zeolite, Bronsted acid, Density Functional Theory

中图分类号:

郑健李强秦玉才祖运宋丽娟. 非骨架铝形态对HY分子筛B酸强度的影响[J]. 石油炼制与化工, 2018, 49(11): 66-71.

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