Hierarchical Porous MOF-199 and Zeolite Composites with High Adsorption Performance for Both Toluene and Acetone

In this study, FAULSP(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 FAULSP triggered morphology evolution and developed new structural defects of MOF-199 due to the coordination of FAULSP and the linker, resulting in a hierarchical porous structure of FAULSP(n)/MOF-199. The SBET of FAULSP(n)/MOF-199 ranged from 1013 to 1344 cm2 g–1, comparable to or even superior to that of MOF-199 (1035 cm2 g–1). FAULSP(n)/MOF-199 had more developed mesoporous structures (Vmes), increased from 0.027 cm3 g–1 of MOF-199 to 0.354 cm3 g–1 of FAULSP(15)/MOF-199. The integrated surface chemistry coupled with the derived hierarchical porous structure provided FAULSP(n)/MOF-199 a good adsorption property of both weakly polar toluene and strongly polar acetone. The FAULSP(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 FAULSP(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 FAULSP(n)/MOF-199 was mostly a physical-adsorption process, in which both monolayer and multilayer adsorption coexisted.