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

Nitrogen
dioxide (NO2) 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 NO2 in a redox−active metal–organic
framework (MOF), MFM-300­(V). Adsorption of NO2 induces
the oxidation of V­(III) to V­(IV) centers in MFM-300­(V), and this is
accompanied by the reduction of adsorbed NO2 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 {NO2·N2O4}∞ chains in the pores of MFM-300­(VIV) results in a high isothermal NO2 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 NO2 for the elimination of air pollutants.