零长柱技术用于分子筛晶内扩散的研究进展

Progress on diffusion studies in zeolites using ZLC techniques

分子筛晶内扩散系数对吸附分离和择形催化具有重要的指导作用。概述了重量法、核磁共振法和分子模拟等分子筛晶内扩散研究方法,并对零长柱技术用于分子筛晶内扩散的原理和应用等方面研究进行了详细阐述,包括两种进样方式(气相进样和液相进样)的单组分气相扩散、二元体系气相扩散和互扩散、液相扩散以及吸附扩散数学模型修正和拓展,还探讨了当前存在的一些问题,最后对零长柱法用于烃类分子在多孔材料中的扩散研究进行了展望。

The intrapartical diffusivity plays an important role in guiding the process of shape-selective catalysis and adsorptive separation. The methods of study on intracrystalline diffusion in zeolites, such as gravimetric method, NMR technique and molecular simulation, were summarized firstly. Furthermore, recent progress in development and application of Zero Length Column（ZLC） method to the measurement of intracrystalline diffusion in zeolites was reviewed, including single component in gas-phased diffusion with two sampling patterns（gas phase and liquid phase sampling）,gas-phased diffusion of binary system and counter diffusion, liquid-phased diffusion, and development of the mathematical models. Some existing problems were also discussed. Finally, application of ZLC method for diffusion of hydrocarbon molecules in the porous materials in the future was prospected.