Structural and Dynamic Analysis of Sulphur Dioxide Adsorption in a Series of Zirconium‐Based Metal–Organic Frameworks

Abstract

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.