Impact of Ni(II) coordinatively unsaturated sites and coordinated water molecules on SO2 adsorption by a MOF with octanuclear metal clusters

Abstract

A Ni-based pyrazolate MOF (NiBDP) is studied for SO2 adsorption under static conditions, demonstrating a high SO2 uptake of 8.48 mmol g−1 at 298 K and 1 bar while maintaining a high chemical stability. The influence of Ni(II) coordinatively unsaturated metal sites and coordinated water on the SO2 adsorption performance of this MOF is investigated by using a combination of experimental techniques, including FTIR and in situ DRIFTS measurements, along with Density Functional Theory calculations. The porefilling of the SO2 adsorbates within the material, at the molecular level, is further unravelled through grand Canonical Monte Carlo simulations employing a newly DFT-derived accurate set of force field parameters.