Encapsulation of a Porous Organic Cage into the Pores of a Metal–Organic Framework for Enhanced CO2 Separation. Issue 15 (3rd February 2020)

• Record Type: Journal Article
• Authors: Liang, Jun; Nuhnen, Alexander; Millan, Simon; Breitzke, Hergen; Gvilava, Vasily; Buntkowsky, Gerd; Janiak, Christoph
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 15(2020)
• Page Start: 6068
• Page End: 6073
• Publication Date: 2020-02-03
• Subjects: carbon dioxide uptake -- cucurbituril -- hybrid materials -- metal–organic frameworks -- porous organic cages; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201916002
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: We present a facile approach to encapsulate functional porous organic cages (POCs) into a robust MOF by an incipient‐wetness impregnation method. Porous cucurbit[6]uril (CB6) cages with high CO2 affinity were successfully encapsulated into the nanospace of Cr‐based MIL‐101 while retaining the crystal framework, morphology, and high stability of MIL‐101. The encapsulated CB6 amount is controllable. Importantly, as the CB6 molecule with intrinsic micropores is smaller than the inner mesopores of MIL‐101, more affinity sites for CO2 are created in the resulting CB6@MIL‐101 composites, leading to enhanced CO2 uptake capacity and CO2 /N2, CO2 /CH4 separation performance at low pressures. This POC@MOF encapsulation strategy provides a facile route to introduce functional POCs into stable MOFs for various potential applications. Abstract : A facile "host‐in‐host" approach has been utilized to prepare functional porous organic molecule based hybrid materials by encapsulating cucurbit[6]uril (CB6) cages into the nanospace of a metal–organic framework. The obtained CB6@MIL‐101 composites are efficient porous adsorbents with enhanced CO2 uptake capacity and CO2 /N2, CO2 /CH4 separation at low pressures.