MIL-100(V) – A mesoporous vanadium metal organic framework with accessible metal sites

Abstract: The large pore vanadium(III) trimesate MIL-100(V), i.e. V3O(H2O)2X[C9H3O6]2·yH2O with , y ≈3 and z ≈0.3, has been synthesized under hydrothermal conditions (MIL stands for Materials from Institute Lavoisier). Its structure, which crystallizes in the space group Fd-3m (No.227) with a =73.0286(2)Å, V =389474.4(2)Å3, exhibits a zeotype architecture with mesoporous cages of approx. 25 and 29Å diameter, accessible through microporous windows of 5.5 and 8.9Å diameter. Synchrotron X-ray powder diffraction analysis confirms its isostructural character with previously reported MIL-100(Cr, Fe, Al) solids. Its thermal stability under O2 and N2, up to 523K (250°C), is comparable to that of MIL-100(Fe). Preliminary gas adsorption experiments and in situ IR-spectroscopy after NO exposure reveal that MIL-100(V) combines high sorption capacities and co-ordinatively unsaturated vanadium sites in different oxidation states (+III and +IV). With these properties this material could be a promising candidate for specific sorption or redox catalytic applications. [Copyright &y& Elsevier]