Encapsulation of a Porous Organic Cage into the Pores of a Metal–Organic Framework for Enhanced CO2 Separation

• DOI: 10.1002/anie.201916002
• Publication Date: 2020-01-08T10:19:01Z
• Authors: Jun Liang; Alexander Nuhnen; Simon Millan; Hergen Breitzke; Vasily Gvilava; Gerd Buntkowsky; Christoph Janiak
• Keywords: 01 natural sciences; Research Articles; 0104 chemical sciences

AbstractWe 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.