Bioinspired Design of a Giant [Mn<sub>86</sub>] Nanocage‐Based Metal‐Organic Framework with Specific CO<sub>2</sub> Binding Pockets for Highly Selective CO<sub>2</sub> Separation
Shubo Geng, Hang Xu, Chun‐Shuai Cao, Tony Pham, Bin Zhao, Zhenjie Zhang
Abstract
Abstract Adsorption‐based removal of carbon dioxide (CO 2 ) from gas mixtures has demonstrated great potential for solving energy security and environmental sustainability challenges. However, due to similar physicochemical properties between CO 2 and other gases as well as the co‐adsorption behavior, the selectivity of CO 2 is severely limited in currently reported CO 2 ‐selective sorbents. To address the challenge, we create a bioinspired design strategy and report a robust, microporous metal–organic framework (MOF) with unprecedented [Mn 86 ] nanocages. Attributed to the existence of unique enzyme‐like confined pockets, strong coordination interactions and dipole‐dipole interactions are generated for CO 2 molecules, resulting in only CO 2 molecules fitting in the pocket while other gas molecules are prohibited. Thus, this MOF can selectively remove CO 2 from various gas mixtures and show record‐high selectivities of CO 2 /CH 4 and CO 2 /N 2 mixtures. Highly efficient CO 2 /C 2 H 2 , CO 2 /CH 4 , and CO 2 /N 2 separations are achieved, as verified by experimental breakthrough tests. This work paves a new avenue for the fabrication of adsorbents with high CO 2 selectivity and provides important guidance for designing highly effective adsorbents for gas separation.