Efficient Mechanochemical Synthesis of MOF-5 for Linear Alkanes Adsorption

An efficient mechanochemical method was proposed to synthesize MOP-5 with high BET area within minutes. The effects of parameters such as solvents activation, the metal/ligand ratio, grinding speed and time were carefully studied and the optimized MOP-5-B was used to investigate its adsorption properties of linear alkanes (C-1-nC(7)). The results showed that solvents activation played an important role in the formation of MOF-5. Besides, the Zn2+/BDC ratio had a great impact on the formation of crystalline MOP-5, and the appropriate Zn2+/BDC ratio was 3:1 for mechanochemical synthesis of MOF-5. Grinding for 60 min could lead to a better crystallinity and the highest surface area of MOP-5-B. The resulting MOF-5-B possessed BET area of 3465.9 m(2).g(-1). More importantly, MOP-S-B showed a preferential adsorption for long alkanes over short alkanes at low pressures. The saturated adsorption capacities of nC(4)-nC(7) decreased with the increase of hydrocarbon chain length. The isosteric heats of C-1-nC(7) increased with the increase of the alkyl chain length. Furthermore, the adsorption capacities of the alkanes (C-3-nC(7)) on MOF-S-B were much higher than those of conventional activated carbons and zeolites.