Abstract:

<p>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 . Here, we demonstrate that CO chemisorption in γ-cylodextrin-based metal-organic frameworks (CD-MOFs) occurs via HCO formation at nucleophilic OH sites within the framework pores, rather than via previously proposed pathways. The new framework KHCO CD-MOF possesses rapid and high-capacity CO uptake, good thermal, oxidative, and cycling stabilities, and selective CO capture under mixed gas conditions. Because of its low cost and performance under realistic conditions, KHCO 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 capture.</p>