Physicochemical and catalytic properties of grafted vanadium species on different mesoporous silicas.
Vanadium modified mesoporous silicas type MCM-41, MCM-48, and SBA-15 are obtained by a solid state method. The samples are characterized and compared at the different steps of their preparation by X-ray diffraction, N(2)-physisorption, FTIR, UV-vis, XPS, and TG-TPR. Samples catalytic activity is tested in ethylacetate oxidation. Formation of various vanadium species, mainly isolated and small oligomeric ones, grafted to the support surface silanol groups, is observed. It is found that the state and the properties of the vanadium species depend on the porous characteristics of the silica host matrix. The nature of the catalytic active center in the ethylacetate oxidation is discussed.
Tsoncheva
Tanya
T
Institute of Organic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria. tsoncheva@orgchm.bas.bg
Ivanova
Ljubomira
L
Dimitrova
Rayna
R
Rosenholm
Jessica
J