Effect of solvents coexistence on the intracrystalline diffusivity of toluene and phenol within Y-type zeolite in the liquid phase
Effect of solvents coexistence on the intracrystalline diffusivity of toluene and phenol within Y-type zeolite in the liquid phase
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DOI：
10.1016/j.micromeso.2022.111694
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发表时间：
2022-01
影响因子：
5.2
通讯作者：
Xinlu Su;Y. Nakasaka;Ren Moriwaki;T. Yoshikawa;T. Masuda
中科院分区：
文献类型：
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作者：
Xinlu Su;Y. Nakasaka;Ren Moriwaki;T. Yoshikawa;T. Masuda
用定容法测定了h - y型沸石（Si/Al = 2.8）在313 ~ 353 K温度范围内，甲苯、苯酚在三甲苯、环己烷和2-丙醇中的晶内扩散系数。甲苯在液相H-Y内的晶内扩散活化能大于气相H-Y孔内共存的溶剂影响了甲苯的扩散机制。甲苯中苯酚在H-Y内的晶内扩散系数小于甲苯。此外，苯酚在脱铝H-Y内的晶内扩散系数高于H-Y内的扩散系数，这进一步表明苯酚分子在H-Y的Brønsted酸位上的吸附更强，这影响了苯酚在酸位上的停留时间，导致扩散系数降低。三种溶剂下苯酚在H-Y内的晶内扩散系数依次为：2-丙醇b>环己烷b>三甲基甲苯。2-丙醇中H-Y吸附苯酚的量相对于其他溶剂中H-Y吸附苯酚的量最小。结果表明，不同溶剂对苯酚在H-Y上的吸附影响了苯酚的晶内扩散率和活化能。
The intracrystalline diffusivities of phenol and toluene within H–Y-type zeolite (Si/Al = 2.8) in the mesitylene, cyclohexane and 2-propanol in the temperature range from 313 to 353 K were measured using the constant volumetric method. The activation energy for the intracrystalline diffusivity of toluene within H–Y in the liquid phase was larger than that in the gas phase, indicating that the solvent coexisting within the H–Y pores affected the diffusion mechanism of toluene. The intracrystalline diffusivity of phenol within H–Y in mesitylene was smaller than that of toluene. Moreover, the intracrystalline diffusivity of phenol within dealuminated H–Y was higher than those within H–Y, which further indicated that the phenol molecule was more strongly adsorbed on the Brønsted acid sites of H–Y, and this affected the residence time of phenol on the acid sites leading to a decrease in the diffusivity. The intracrystalline diffusivities of phenol within H–Y for the three solvents were in the following order: 2-propanol > cyclohexane > mesitylene. The amount of adsorbed phenol on H–Y in 2-propanol was smallest relative to the amounts of phenol adsorbed on H–Y in the other solvents. The results indicated that the adsorption of phenol on H–Y in the different solvents affected the intracrystalline diffusivity of phenol and its activation energy.