Implementation of a Core-Shell Design Approach for Constructing MOFs for CO 2 Capture

• Published in: ACS applied materials & interfaces 2023-05, Vol.15 (19), p.23337-23342
• Main Authors: He, Yiwen, Boone, Paul, Lieber, Austin R, Tong, Zi, Das, Prasenjit, Hornbostel, Katherine M, Wilmer, Christopher E, Rosi, Nathaniel L
• Format: Article
• Language: English
• Subjects: Materials Science; Science & Technology - Other Topics
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.3c03457

Adsorption-based capture of CO from flue gas and from air requires materials that have a high affinity for CO and can resist water molecules that competitively bind to adsorption sites. Here, we present a core-shell metal-organic framework (MOF) design strategy where the core MOF is designed to selectively adsorb CO , and the shell MOF is designed to block H O diffusion into the core. To implement and test this strategy, we used the zirconium (Zr)-based UiO MOF platform because of its relative structural rigidity and chemical stability. Previously reported computational screening results were used to select optimal core and shell MOF compositions from a basis set of possible building blocks, and the target core-shell MOFs were prepared. Their compositions and structures were characterized using scanning electron microscopy, transmission electron microscopy, and powder X-ray diffraction. Multigas (CO , N , and H O) sorption data were collected both for the core-shell MOFs and for the core and shell MOFs individually. These data were compared to determine whether the core-shell MOF architecture improved the CO capture performance under humid conditions. The combination of experimental and computational results demonstrated that adding a shell layer with high CO /H O diffusion selectivity can significantly reduce the effect of water on CO uptake.