Selectivity and direct visualization of carbon dioxide and sulfur dioxide in a decorated porous host

Abstract

Understanding the mechanism by which porous solids trap harmful gases such as CO2 and SO2 is essential for the design of new materials for their selective removal. Materials functionalized with amine groups dominate this field, largely because of their potential to form carbamates through H2N(δ−)···C(δ+)O2 interactions, thereby trapping CO2 covalently. However, the use of these materials is energy-intensive, with significant environmental impact. Here, we report a non-amine-containing porous solid (NOTT-300) in which hydroxyl groups within pores bind CO2 and SO2 selectively. In situ powder X-ray diffraction and inelastic neutron scattering studies, combined with modelling, reveal that hydroxyl groups bind CO2 and SO2 through the formation of O=C(S)=O(δ−)···H(δ+)–O hydrogen bonds, which are reinforced by weak supramolecular interactions with C–H atoms on the aromatic rings of the framework. This offers the potential for the application of new ‘easy-on/easy-off’ capture systems for CO2 and SO2 that carry fewer economic and environmental penalties. Porous solids are well suited to the capture of environmentally harmful gases, but further understanding of the solid–gas interactions involved is required. Combining dynamic and static characterization with modelling, researchers have now described how a metal–organic framework binds CO2 and SO2 selectively through hydroxyl groups — rather than amine ones as typically featured.

Cite this article

Yang, S., Sun, J., Ramirez-Cuesta, A. et al. Selectivity and direct visualization of carbon dioxide and sulfur dioxide in a decorated porous host. Nature Chem 4, 887–894 (2012). https://doi.org/10.1038/nchem.1457

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