Carbon Dioxide Capture at Nucleophilic Hydroxide Sites in Oxidation‐Resistant Cyclodextrin‐Based Metal–Organic Frameworks**

Abstract

Abstract Carbon capture and sequestration (CCS) from industrial point sources and direct air capture are necessary to combat global climate change. A particular challenge faced by amine‐based sorbents—the current leading technology—is poor stability towards O 2 . Here, we demonstrate that CO 2 chemisorption in γ‐cylodextrin‐based metal–organic frameworks (CD‐MOFs) occurs via HCO 3 − formation at nucleophilic OH − sites within the framework pores, rather than via previously proposed pathways. The new framework KHCO 3 CD‐MOF possesses rapid and high‐capacity CO 2 uptake, good thermal, oxidative, and cycling stabilities, and selective CO 2 capture under mixed gas conditions. Because of its low cost and performance under realistic conditions, KHCO 3 CD‐MOF is a promising new platform for CCS. More broadly, our work demonstrates that the encapsulation of reactive OH − sites within a porous framework represents a potentially general strategy for the design of oxidation‐resistant adsorbents for CO 2 capture.