Highly Selective Separations of C2H2/C2H4 and C2H2/C2H6 in Metal-Organic Frameworks via Pore Environment Design

C2 hydrocarbon separation is one of the most important industrial issues in the petrochemical industry. As an energy-efficient method, the C2 hydrocarbon separation using metal–organic frameworks (MOFs) has attracted considerable attention. In this work, adsorption and separation performances of C2H2/C2H4 and C2H2/C2H6 mixtures in four MOFs, including Zn2(bdc)2(bpy), Zn2(bdc)2(bpy)-ZnF2, Zn2(tmbdc)2(bpy), and Zn2(tmbdc)2(bpy)-ZnF2, were investigated by grand canonical Monte Carlo methods. The effects of pore sizes and surface chemical functions of MOFs on C2 hydrocarbon separations at room temperature were deeply analyzed. Besides, density functional theory calculations were carried out to clarify the underlying mechanisms in adsorption and separation processes. The results indicate that our newly developed Zn2(tmbdc)2(bpy)-ZnF2 shows ultrahigh C2H2/C2H4 and C2H2/C2H6 selectivities. Particularly, the C2H2/C2H4 selectivity of Zn2(tmbdc)2(bpy)-ZnF2 is nearly a hundred times higher than that of NOTT-300. Thi...