Monte Carlo simulation study of the halogenated MIL-47(V) frameworks: influence of functionalization on H2S adsorption and separation properties

Monte Carlo simulation calculations were performed to explore the H2S adsorption and separation in the initial MIL-47(V) and the monohalogenated MIL-47(V)-X (X = F, Cl, Br). Both initial and halogenated MIL-47(V) metal-organic framework materials (MOFs) exhibit an ultra-high H2S adsorption ability, which is much higher than that of CH4 and N-2. Halogen functionalization could enhance the H2S uptake in unit volume of MOFs especially in low-pressure range, with the sequence: MIL-47(V) < MIL-47(V)-F < MIL-47(V)-Cl < MIL-47(V)-Br, according with the increasing polarizability of the linkers, whereas the H2S mass fraction follows an inverse order MIL-47(V) > MIL-47(V)-F > MIL-47(V)-Cl > MIL-47(V)-Br, because of the increasing mass density of MOFs after halogenation. The adsorption behavior of four MOFs for the H2S/CH4 and H2S/N-2 mixtures are explored as a function of both pressure and H2S mole fraction, and all of four MOFs show the ultraselectivity toward H2S molecule. Compared to the initial MIL-47(V), the halogenated MOFs exhibit the preferable H2S/CH4 and H2S/N-2 selectivity under the conditions of low temperature, high pressure, and high H2S mole fraction. [GRAPHICS] .