Synthesis of TS-1 molecular sieves using a new Ti source.
The incorporation of Ti in the MFI structure using a cheap and easy to handle source, the hexafluorotitanic acid, was successfully achieved without the formation of contaminant phases. The TS-1 samples with 1%, 2%, and 2.5% Ti present a linear increase in the cell parameters. This indicates that the Ti present in the solid is incorporated into the framework, and this is confirmed by infrared analysis. The TS-1 particles present morphology that is typical of the MFI structure. The UV-vis diffuse reflectance results indicate the existence of tetra- and hexacoordinated framework Ti species. Independent of Ti content, all of the samples present similar activity for the oxidation of cyclohexene using hydrogen peroxide as an oxidant agent. Also, a high selectivity for the formation of the corresponding epoxide is observed.
Borin
Mario F
MF
Department of Chemical Engineering, Federal University of São Carlos, P.O. Box 676, 13565-905 S. Carlos, SP, Brazil.
da Silva
Teresa
T
Felisbino
Romilda Fernandez
RF
Cardoso
Dilson
D