Shell engineering on mesoporous metal organic frameworks: beyond microporous restriction in core-shell architecture
Shi Lijuan , Deyun Sun , Hongxue Xu , Zunaira Maqsood , Chen Shangqing , Qun Yi
2025 Green Chemical Engineering DOI: 10.1016/j.gce.2025.02.002
Abstract
Core-shell metal organic frameworks (MOFs) have emerged as a promising platform for efficient separation and sensing, benefiting from the sieving effect of the shell and the large storage capacity of the core. However, conventional core-shell MOFs often encounter challenges with compromised pore integrity, which predominantly restricts their design to microporous cores. In this study, a straightforward strategy to construct functional shells on mesoporous MOFs is proposed. By leveraging dynamic imine chemistry, small-molecule amines are assembled into supramolecular polymers and anchored onto the surface of mesoporous MOFs through metal coordination. This approach preserves the mesoporous structure of the core while introducing hydrogen-bonding channels in the shell, facilitating the selective capture and storage of polar gases. The resulting core-shell MOF demonstrates exceptional CO2/N2 selectivity of up to 10,943 and a high CO2 adsorption capacity, enabling the direct production of high-purity CO2 (99.7 vol.%) from humid flue gas in a single breakthrough experiment. Furthermore, this strategy exhibits excellent stability and versatility across various mesoporous MOFs, underscoring its potential for practical industrial gas separation applications.
核壳金属有机框架（MOFs）因其外壳的筛分效应和核的大存储容量，已成为高效分离和传感的有前景平台。然而，传统的核壳MOFs通常面临孔隙完整性受损的挑战，这主要限制了其设计以微孔核为主。在本研究中，提出了一种在介孔MOFs上构建功能外壳的直接策略。通过利用动态亚胺化学，小分子胺被组装成超分子聚合物，并通过金属配位锚定到介孔MOFs的表面。这种方法在保留介孔核结构的同时，在外壳中引入了氢键通道，从而促进了极性气体的选择性捕获和存储。所得的核壳MOF表现出高达10,943的优异CO2/N2选择性以及高CO2吸附能力，能够在单一穿透实验中直接从潮湿烟道气中生产高纯度CO2（99.7 vol.%）。此外，该策略在各种介孔MOFs中展现出卓越的稳定性和通用性，突显了其在实际工业气体分离应用中的潜力。
