Hierarchical Porous MOF-199 and Zeolite Composites with High Adsorption Performance for Both Toluene and Acetone
Xiaomi Meng, Zhongde Dai, Charles Q. Jia, Lin Yang, Wenju Jiang, Lu Yao, Qiying Zhou, Bo Xu
Abstract
In this study, FAU LSP ( n )/MOF-199 composites with hierarchical porous structures have been synthesized by zeolite-induced in situ growth of MOF-199 and applied for efficient adsorption of toluene and acetone. The results revealed that the presence of FAU LSP triggered morphology evolution and developed new structural defects of MOF-199 due to the coordination of FAU LSP and the linker, resulting in a hierarchical porous structure of FAU LSP ( n )/MOF-199. The S BET of FAU LSP ( n )/MOF-199 ranged from 1013 to 1344 cm 2 g –1, comparable to or even superior to that of MOF-199 (1035 cm 2 g –1 ). FAU LSP ( n )/MOF-199 had more developed mesoporous structures ( V mes ), increased from 0.027 cm 3 g –1 of MOF-199 to 0.354 cm 3 g –1 of FAU LSP (15)/MOF-199. The integrated surface chemistry coupled with the derived hierarchical porous structure provided FAU LSP ( n )/MOF-199 a good adsorption property of both weakly polar toluene and strongly polar acetone. The FAU LSP (4)/MOF-199 showed the best adsorption performance with saturated adsorption capacities of 430.2 and 311.1 mg g –1 of toluene and acetone at 25 °C and 1000 mg m –3 . The FAU LSP ( n )/MOF-199 also exhibited excellent adsorption–desorption stability, with only 4.55 and 8.05% capacity loss of toluene and acetone after five adsorption–desorption cycles. According to the characterization before and after adsorption, the kinetic and thermodynamic studies knew that the adsorption of toluene and acetone on FAU LSP ( n )/MOF-199 was mostly a physical-adsorption process, in which both monolayer and multilayer adsorption coexisted.