Nickel-based metal–organic framework for efficient capture of CF4 with a high CF4/N2 selectivity

An ultra-stable nickel-based MOF is reported with multiple anthracene rings-functionalized ultramicroporous chemistry for the capture of CF 4 from the gas mixture. It presents a high CF 4 uptake and excellent CF 4 /N 2 selectivity with a good regeneration property. • Ni(ADC)(DABCO) 0.5 exhibits an excellent CF 4 /N 2 selectivity and high CF 4 uptake . • Breakthrough tests confirm a complete separation of CF 4 /N 2 mixture. • It owns a superb framework stability and regeneration. • Anthracene-ring-functionalized pore plays a key role on the separation effect. Pursuing top-performing materials with excellent structural stability and regeneration to fulfill effective adsorption of tetrafluoromethane (CF 4 ) from the CF 4 /N 2 mixture is of great significance. Herein, a highly stable Ni-MOF, named Ni(ADC)(DABCO) 0.5 with anthracene rings-functionalized ultramicroporous chemistry, was prepared to effectively separate the gaseous CF 4 /N 2 blend. Thermodynamic equilibrium adsorption indicates that the Ni(ADC)(DABCO) 0.5 owns an excellent CF 4 adsorption capacity (0.52 mmol g -1 ) at 298 K and 0.1 bar, exceeding most of the materials reported until now. Especially, the corresponding selectivity (23.0) at 1.0 bar is higher than that of most existing materials and solves the trade-off issue between CF 4 /N 2 separation selectivity and CF 4 uptake. Meanwhile, the separation mechanism underlying the disparity of material affinity toward CF 4 and N 2 was deciphered via the DFT result. Furthermore, the stronger interaction between the host framework and CF 4 molecule is owing to the shorter affinity distance between the pore inner wall and F atom on CF 4 . Dynamic breakthrough examinations verify this material can utterly separate the CF 4 /N 2 (10/90) blend. In combination with superb framework stability and regeneration, this MOF may be a promising candidate toward the recovery of CF 4 from the CF 4 /N 2 mixture.