Diffusion of phenolic compounds within high-silica MFI-type zeolite in the mesitylene solution
Diffusion of phenolic compounds within high-silica MFI-type zeolite in the mesitylene solution
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DOI：
10.1016/j.micromeso.2021.111044
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发表时间：
2021-03
影响因子：
5.2
通讯作者：
Xinluona Su;Y. Nakasaka;Ren Moriwaki;T. Yoshikawa;T. Masuda
中科院分区：
文献类型：
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作者：
Xinluona Su;Y. Nakasaka;Ren Moriwaki;T. Yoshikawa;T. Masuda
用恒容积法测定了在313~353K温度范围内，酚类化合物(苯酚、对丙基苯酚和间甲酚)和甲苯在Silicalite-1沸石和MFI型沸石(H-MFI)中的晶内扩散系数。在313、323和353K时，Silicalite-1对苯酚、对丙基苯酚和甲苯的吸附量大致相同，而较小的甲酚则因其较大的动力学直径而被吸附。与吸附甲苯不同，苯酚在H-MFI上的吸附表现出比在Silicalite-1上更强的相互作用，这表明苯酚的羟基与H-MFI上的Brnsted酸位之间的氢键促进了苯酚的吸附。而苯酚、对丙基苯酚和甲苯在Silicalite-1中的晶内扩散系数基本相同，而间甲酚的晶内扩散系数较小，表明晶内扩散系数受几何限制。苯酚在含酸中心的H-MFI中的晶内扩散系数比在Silicalite-1中低。苯酚在酸性中心的停留时间比甲苯长，这导致了苯酚和甲苯在H-MFI中晶内扩散系数的差异。
The intracrystalline diffusivity of phenolic compounds (phenol,p-propylphenol andm-cresol) and toluene within silicalite-1 and MFI-type zeolite with Si/Al = 303 (H-MFI) in the liquid phase (solvent: mesitylene) in the temperature range from 313 to 353 K were measured by using the constant volumetric method. The amounts of phenol,p-propylphenol, and toluene adsorbed onto silicalite-1 at 313, 323 and 353 K were approximately the same, whereas lessm-cresol was adsorbed because of its larger kinetic diameter. Unlike adsorbed toluene, adsorbed of phenol displayed stronger interactions in H-MFI than in silicalite-1, indicating that hydrogen bonding between the OH group of phenol and Brønsted acid sites in H-MFI enhanced the adsorption of phenol. Whereas the intracrystalline diffusivity of phenol,p-propylphenol, and toluene within silicalite-1 are approximately the same,m-cresol exhibited lower intracrystalline diffusivity, indicating that the intracrystalline diffusivity was governed by geometrical limitation. The intracrystalline diffusivity of phenol was lower within H-MFI with acid sites than within silicalite-1. The residence time of phenol on the acid sites became longer than that of toluene, which led to a difference in the intracrystalline diffusivity between phenol and toluene within H-MFI.