Mixed Metal–Organic Framework with Multiple Binding Sites for Efficient C2H2/CO2Separation

Abstract

AbstractThe separation of C2H2/CO2is particularly challenging owing to their similarities in physical properties and molecular sizes. Reported here is a mixed metal–organic framework (M′MOF), [Fe(pyz)Ni(CN)4] (FeNi‐M′MOF, pyz=pyrazine), with multiple functional sites and compact one‐dimensional channels of about 4.0 Å for C2H2/CO2separation. This MOF shows not only a remarkable volumetric C2H2uptake of 133 cm3 cm−3, but also an excellent C2H2/CO2selectivity of 24 under ambient conditions, resulting in the second highest C2H2‐capture amount of 4.54 mol L−1, thus outperforming most previous benchmark materials. The separation performance of this material is driven by π–π stacking and multiple intermolecular interactions between C2H2molecules and the binding sites ofFeNi‐M′MOF. This material can be facilely synthesized at room temperature and is water stable, highlightingFeNi‐M′MOFas a promising material for C2H2/CO2separation.