A robust Th-azole framework for highly efficient purification of C(2)H(4) from a C(2)H(4)/C(2)H(2)/C(2)H(6) mixture

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.