A robust Th-azole framework for highly efficient purification of C2H4 from a C2H4/C2H2/C2H6 mixture

Abstract Separation of C 2 H 4 from C 2 H 4 /C 2 H 2 /C 2 H 6 mixture with high working capacity is still a challenging task. Herein, we deliberately design a Th-metal-organic framework (MOF) for highly efficient separation of C 2 H 4 from a binary C 2 H 6 /C 2 H 4 and ternary C 2 H 4 /C 2 H 2 /C 2 H 6 mixture. The synthesized MOF Azole-Th-1 shows a UiO-66-type structure with fcu topology built on a Th 6 secondary building unit and a tetrazole-based linker. Such noticeable structure, is connected by a N,O-donor ligand with high chemical stability. At 100 kPa and 298 K Azole-Th-1 performs excellent separation of C 2 H 4 (purity > 99.9%) from not only a binary C 2 H 6 /C 2 H 4 (1:9, v/v) mixture but also a ternary mixture of C 2 H 6 /C 2 H 2 /C 2 H 4 (9:1:90, v/v/v), and the corresponding working capacity can reach up to 1.13 and 1.34 mmol g −1 , respectively. The separation mechanism, as unveiled by the density functional theory calculation, is due to a stronger van der Waals interaction between ethane and the MOF skeleton.