Pore Environmental Modification by Amino Groups in Robust Microporous MOFs for SF<sub>6</sub> Capturing and SF<sub>6</sub>/N<sub>2</sub> Separation
Yongpeng Li, J.L. Ni, Xiaojie Zhang, Xiaolong Zhang, Wen Wen, Zhuyin Sui, Xiufeng Xu
Abstract
Capturing and separating the greenhouse gas SF 6 from nitrogen N 2 have significant greenhouse mitigation potential and economic benefits. We used a pore engineering strategy to manipulate the pore environment of the metal–organic framework (MOF) by incorporating organic functional groups (−NH 2 ). This resulted in an enhanced adsorption of SF 6 and separation of the SF 6 /N 2 mixture in the MOF. The introduction of amino (−NH 2 ) groups into YTU-29 resulted in a reduction of the Brunauer–Emmett–Teller surface but an increase in interactions with SF 6 within the confined pores. Water-stable YTU-29-NH 2 showed a significantly higher SF 6 uptake (95.5 cm 3 /g) than YTU-29 (77.4 cm 3 /g). The results of the breakthrough experiments show that YTU-29-NH 2 has a significantly improved separation performance for SF 6 /N 2 mixtures, with a high SF 6 capture of 0.88 mmol/g compared to 0.56 mmol/g by YTU-29. This improvement is due to the suitable pore confinement and accessible −NH 2 groups on pore surfaces. Considering its excellent regeneration ability and cycling performance, ultrastable YTU-29-NH 2 demonstrates great potential for SF 6 capturing and SF 6 /N 2 separation.