Abstract
The separation of C(2) H(2) /CO(2) is 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 C(2) H(2) /CO(2) separation. This MOF shows not only a remarkable volumetric C(2) H(2) uptake of 133 cm(3) cm(-3) , but also an excellent C(2) H(2) /CO(2) selectivity of 24 under ambient conditions, resulting in the second highest C(2) H(2) -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 C(2) H(2) molecules and the binding sites of FeNi-M'MOF. This material can be facilely synthesized at room temperature and is water stable, highlighting FeNi-M'MOF as a promising material for C(2) H(2) /CO(2) separation.