Immobilization of Amino-site into a Pore-Partitioned Metal-Organic Framework for Highly Efficient Separation of Propyne/Propylene.

Adsorptive separation of propyne/propylene (CH/CH) is a crucial yet complex process, however, it remains a great difficulty in developing porous materials that can meet the requirements for practical applications, particularly with an exceptional ability to bind and store trace amounts of CH. Functionalization of pore-partitioned metal-organic frameworks (ppMOFs) is methodically suited for this challenge owing to the possibility of dramatically increasing binding sites on highly porous and confined domains. We here immobilized Lewis-basic (-NH) and Lewis-acidic (-NO) sites on this platform. Along with an integrated nature of high uptake of CH at 1 kPa, high uptake difference of CH-CH, moderated binding strength, promoted kinetic selectivity, trapping effect and high stability, the NH-decorated ppMOF (NTU-100-NH) can efficiently produce polymer-grade CH (99.95 %, 8.3 mmol ⋅ g) at room temperature, which is six times more than the NO-decorated crystal (NTU-100-NO). The in situ infrared spectroscopy, crystallographic analysis, and sequential blowing tests showed that the densely packed amino group in this highly porous system has a unique ability to recognize and stabilize CH molecules. Moving forward, the strategy of organic functionalization can be extended to other porous systems, making it a powerful tool to customize advanced materials for challenging tasks.