Fine-tuning the pore environment of isoreticular metal-organic frameworks through installing functional sites for boosting C2H6/C2H4 separation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-04, Vol.485, p.149587, Article 149587
• Main Authors: Wang, Gang-Ding, Li, Yong-Zhi, Krishna, Rajamani, Yan, Zhi-Zhu, Hou, Lei, Wang, Yao-Yu, Zhu, Zhonghua
• Format: Article
• Language: English
• Subjects: C2H6-selective MOFs; C2H6/C2H4 separation; Metal-organic framework; Pore engineering; Reticular chemistry
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.149587

By virtue of pore engineering strategy based on reticular chemistry, we finely tuned the pore environment of isoreticular MOFs via installing functional sites to improve the ethane/ethylene separation performance greatly compared to parent MOF. [Display omitted] •Pore environments of four MAF-X10 systems were successfully engineered.•MAF-X10(F) displayed high uptake and selectivity for C2H6 over C2H4.•MAF-X10(F) showed significantly improved C2H6/C2H4 separation performances.•Accessible F sites in pores are responsible for increased separation performances. Herein, we presented a strategy that tuning the pore environment via installing functional sites in the pores to boost C2H6/C2H4 separation performance of MOFs. To prove this strategy, four isoreticular MOFs [MAF-X10, -X10(Me), -X10(Cl), and -X10(F)] were designed and synthesized based on reticular chemistry principle, which featured the regulated pore environment and exhibited intriguing differences in C2H6 and C2H4 uptakes. Methyl group-modified nonpolar pores endow these MOFs with impressive C2H6-selective behavior and high C2H6 loadings (>110 cm3 g−1), in which MAF-X10(F) with polar F sites exhibited the highest C2H6 uptake (140.5 cm3 g−1) among four MOFs, ranking the top compared to the reported MOF materials. The polar sites-functionalized MAF-X10(Cl) and -X10(F) showed the significantly improved C2H6/C2H4 separation performances in comprehensive of selectivity, separation potential, C2H4 productivity, which were mainly contributed to the strong C-H⋯Cl/F interactions formed between the active sites (Cl or F) in MAF-X10(Cl)/(F) and C2H6, as revealed by molecular simulations.