The Structure-Property Relationship of Oxovanadium(iv) Complexes in the Wall Framework of PMOs and Their Catalytic Applications

Oxovanadium(IV) species could be considered as effective active sites in the catalytic oxidation reactions, but in the traditional vanadium-containing catalysts, the unstable and undispersible status of these active sites cause great limitation in their application. In this study, we present a novel approach to utilize the co-condensation of the silica source with oxovanadium organic complexes through the liquid crystal templating (LCT) process introducing the vanadium species into the framework of periodically meosporous organosilicas (PMOs). Oxovanadium organic complexes are successfully obtained by the coordination effect between vanadium species and organic complexes. Thus the vanadium-containing PMOs catalysts are accordingly synthesized; the model structure of as-prepared catalysts is proposed and further verified by different characterization measurements. These vanadium-containing PMOs catalysts display the extremely stable and well-dispersed oxovanadium(IV) species in the framework, and due to this advanced structure, the corresponding excellent catalytic properties of these catalysts in styrene oxidation reaction are obtained. (C) 2016 Elsevier B.V. All rights reserved.