Aluminum-based metal organic frameworks for greenhouse gases CF4 and C2F6 capture with excellent capacity and selectivity

The capture and recovery of perfluorinated greenhouse gases CF 4 and C 2 F 6 from industrial exaust can not only mitigate global warming but also produce value-added products. Adsorption technology based on porous materials is promising for such purpose, while adsorbents with high capacity and selectivity are still lacking due to the chemical inertness of CF 4 and C 2 F 6 . Herein, three ultra-microporous Al-MOFs with multiple electropositive binding sites in 1D channel were synthesized and evaluated for CF 4 /C 2 F 6 adsorption. Among the synthesized Al-MOFs, Al-Fum displayed the best adsorption performance due to its desirable pore environment. It has a record-breaking C 2 F 6 adsorption capacity (3.30 mmol/g at 1 bar and 298 K) and C 2 F 6 /N 2 (10/90, v/v) selectivity (299.6 at 1 bar). In addition, it also displays excellent CF 4 adsorption performance, exceeding most of the reported adsorbents. Theoretical simulations demonstrate the high CF 4 /C 2 F 6 affinity towards Al-Fum is resulted from the multiple interactions of F atoms with H atoms of fumarate linkers and corner hydroxyl groups in frameworks. Moreover, dynamic column breakthrough tests confirmed the excellent separation performance of CF 4 /N 2 and C 2 F 6 /N 2 on Al-Fum with outstanding regenerability. Due to the green and energy-efficient synthesis method and outstanding adsorption performance, Al-Fum is considered to be an ideal porous material for CF 4 /C 2 F 6 capture under practical conditions.