A robust Th-azole framework for highly efficient purification of CH from a CH/CH/CH mixture.

Separation of CH from CH/CH/CH 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 CH from a binary CH/CH and ternary CH/CH/CH mixture. The synthesized MOF Azole-Th-1 shows a UiO-66-type structure with fcu topology built on a Th 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 CH (purity > 99.9%) from not only a binary CH/CH (1:9, v/v) mixture but also a ternary mixture of CH/CH/CH (9:1:90, v/v/v), and the corresponding working capacity can reach up to 1.13 and 1.34 mmol g, 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.