Water-insoluble hybrid materials based on polyoxomolybdate nanoclusters as efficient catalysts

Abstract

In the current study, we hydrothermally synthesized polyoxomolybdate-based hybrid materials, [Zn(4,4´-bpy)2(H2O)4]3(Mo8O26)2(NH4)2(4,4´-bpy)6 (1) and [(4,4´-H2bpy)2(H2P2Mo5O23)].2H2O (2) based on β-octamolybdate and Strandberg-type structures using 4,4´-bipyridine (4,4´-bpy) ligand. Structure of the obtained materials was investigated by single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), FT-IR and inductive coupled plasma optical emission spectroscopy (ICP-OES). The crystals were insoluble in water and employed as catalysts for the catalytic wet air oxidation (CWAO) as well as catalytic wet oxidation (CWO) of Direct Blue 71 (DB) as a representative of a tri-azo dye pollutant under mild conditions. The POM catalysts exhibited good catalytic activity under ambient conditions and could be reused without loss of crystallinity and activity.