A robust aluminum-octacarboxylate framework with topology for selective capture of sulfur dioxide.

The high structural diversity and porosity of metal-organic frameworks (MOFs) promote their applications in selective gas adsorption. The development of robust MOFs that are stable against corrosive SO remains a daunting challenge. Here, we report a highly robust aluminum-based MOF (HIAM-330) built on a 4-connected Al(OH)(COO) cluster and 8-connected octacarboxylate ligand with a (4,8)-connected topology. It exhibits a fully reversible SO uptake of 12.1 mmol g at 298 K and 1 bar. It is capable of selective capture of SO over other gases (CO, CH, and N) with high adsorption selectivities of 60, 330, and 3537 for equimolar mixtures of SO/CO, SO/CH, and SO/N, respectively, at 298 K and 1 bar. Breakthrough measurements verified the capability of HIAM-330 for selective capture of SO (2500 ppm) over CO or N. High-resolution synchrotron X-ray powder diffraction of SO loaded HIAM-330 revealed the binding domains of adsorbed SO molecules and host-guest interactions.