Adsorption of Nitrogen Dioxide in a Redox-Active Vanadium Metal–Organic Framework Material

Nitrogen dioxide (NO 2 ) is a toxic air pollutant, and efficient abatement technologies are important to mitigate the many associated health and environmental problems. Here, we report the reactive adsorption of NO 2 in a redox-active metal-organic framework (MOF), MFM-300(V). Adsorption of NO 2 induces the oxidation of V(III) to V(IV) centers in MFM-300(V), and this is accompanied by the reduction of adsorbed NO 2 to NO and the release of water via deprotonation of the framework hydroxyl groups, as confirmed by synchrotron X-ray diffraction and various experimental techniques. The efficient packing of {NO 2 ·N 2 O 4 } ∞ chains in the pores of MFM-300(V IV ) results in a high isothermal NO 2 uptake of 13.0 mmol g -1 at 298 K and 1.0 bar and is retained for multiple adsorption-desorption cycles. This work will inspire the design of redox-active sorbents that exhibit reductive adsorption of NO 2 for the elimination of air pollutants.