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We report reversible high capacity adsorption of SO2 in robust Zr‐based metal–organic framework (MOF) materials. Zr‐bptc (H4bptc=biphenyl‐3,3′,5,5′‐tetracarboxylic acid) shows a high SO2 uptake of 6.2 mmol g−1 at 0.1 bar and 298 K, reflecting excellent capture capability and removal of SO2 at low concentration (2500 ppm). Dynamic breakthrough experiments confirm that the introduction of amine, atomically‐dispersed CuII or heteroatomic sulphur sites into the pores enhance the capture of SO2 at low concentrations. The captured SO2 can be converted quantitatively to a pharmaceutical intermediate, aryl N‐aminosulfonamide, thus converting waste to chemical values. In situ X‐ray diffraction, infrared micro‐spectroscopy and inelastic neutron scattering enable the visualisation of the binding domains of adsorbed SO2 molecules and host–guest binding dynamics in these materials at the atomic level. Refinement of the pore environment plays a critical role in designing efficient sorbent materials. [ABSTRACT FROM AUTHOR]

Air pollution by SO2 and NO2 has caused significant risks on the environment and human health. Understanding the mechanism of active sites within capture materials is of fundamental importance to the development of new clean‐up technologies. Here we report the crystallographic observation of reversible coordinative binding of SO2 and NO2 on open NiII sites in a metal‐organic framework (NKU‐100) incorporating unprecedented {Ni12}‐wheels; each wheel exhibits six open NiII sites on desolvation. Immobilised gas molecules are further stabilised by cooperative host‐guest interactions comprised of hydrogen bonds, π⋅⋅⋅π interactions and dipole interactions. At 298 K and 1.0 bar, NKU‐100 shows adsorption uptakes of 6.21 and 5.80 mmol g−1 for SO2 and NO2, respectively. Dynamic breakthrough experiments have confirmed the selective retention of SO2 and NO2 at low concentrations under dry conditions. This work will inspire the future design of efficient sorbents for the capture of SO2 and NO2. [ABSTRACT FROM AUTHOR]

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(??)···C(?+)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(??)···H(?+)-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. [ABSTRACT FROM AUTHOR]