Research on the correlation between dynamic diameters of hydrocarbon molecules and zeolites shape-selective catalytic performance

doi:10.16085/j.issn.1000-6613.2016.s1.028

Abstract

Abstract: As an important branch of today's molecular sieve research, shape selectivity in zeolite catalysis has been exploited by industry for almost 60 years.Though our mechanistic research remains rather limited, the researchers made satisfactory progress in our understanding of shape-selective catalysis, with the development of catalytic reaction types, the synthesis of new catalysts, zeolites structure determination, catalytic performance, and catalytic mechanism in research.Here we summarize the different hydrocarbon molecules' absorption and diffusion behaviors in the pores of zeolites based on the current studies, and also explore the correlation between dynamic diameters of hydrocarbon molecules and their shape-selectivity in zeolites catalysis.By analysis, there exists a rule of the correlation between dynamic diameters of hydrocarbon molecules and their shape-selectivity in zeolites catalysis applicable in an interval, the zeolites achieved best catalytic performance only when reactant's dynamic diameter slightly smaller than or close to zeolite's pore diameter.Besides, zeolite's topology also have an effect on its catalytic performance.

Key words: dynamic diameter, diffusion energy barriers, shape-selectivity catalysis, topology

摘要： 作为分子筛研究领域的一个热点,择形催化理论在工业上已经被研究了近60年。尽管在理论上很多研究还不够深入,但随着对催化反应类型、新型催化材料合成、分子筛结构测定、催化性能表征、催化反应作用机理等方面研究的深入,对择形催化反应的认识仍取得了令人欣慰的进步。本文在现有的研究基础上,对不同尺寸的烃分子在分子筛孔道内的吸附和扩散行为进行了总结,并对烃分子反应动力学直径与分子筛的择形相关性做了一定的探究。分析表明,烃分子的反应动力学直径与分子筛择形催化相关性存在一个适用规律区间,当其略小于或接近分子筛孔径时,分子筛的择形催化性能表现最好。此外,分子筛本身的拓扑结构等因素也会对分子筛催化性能造成影响。

关键词: 动力学直径, 扩散能垒, 择形催化, 拓扑结构

CLC Number:

TE621

WU Jie. Research on the correlation between dynamic diameters of hydrocarbon molecules and zeolites shape-selective catalytic performance[J]. Chemical Industry and Engineering Progree, 2016, 35(S1): 167-173.

武杰. 烃分子动力学直径与分子筛择形催化性能的相关性[J]. 化工进展, 2016, 35(S1): 167-173.

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