Mesoporous silicates with spherical morphology modified with vanadium, highly active in oxidation of cyclohexene with H2O2

C.M. CHANQUíA; A.L. CáNEPA; K. SAPAG; J. VILLARROEL; M.E. CRIVELLO; E.R. HERRERO; S.G. CASUSCELLI; G.A. EIMER

San Pedro

Simposio; Fifth San Luis Symposium on Surfaces, Interfaces and Catalysis; 2010

In this work mesoporous molecular sieves type MCM-41 were synthesized with different Vanadium content in the initial synthesis gel. These materials showed spherical morphology with a narrow particle size distribution between 2-4 ìm. The techniques used for physicochemical characterization of these catalysts were: XRD, AAS, N2 physisorption, SEM, TEM, DR-UV-vis and FT-IR-Py. All materials presented high specific surface area (> 900 m2/g), characteristic of MCM-41 materials. By TEM measures was observed a well-defined mesoporous structure; however there was no one-dimensional ordering of pores characteristic of such materials. The sample synthesized with the highest content of V presented marked differences in their structural characteristics ascribed to the presence of V2O5 nano-particles. From analysis of DR-UV-vis it was infer a successful incorporation of cations V5+ to silica structure in tetrahedral coordination with oxygen of the network. The catalytic activity of these materials was evaluated in the test reaction of cyclohexene oxidation using H2O2 as an oxidizing agent, showing a high conversion ~ 93 % respect to maximum.