Surface modified amorphous titanosilicate catalysts for liquid phase epoxidation

Titanium-containing mesoporous silica has been prepared by silylation of mi xed oxides obtained via sol-gel method. These samples displayed enhanced ac tivity in the epoxidation of styrene with (BuOOH)-O-t in comparison to norm al xerogels or other titanium-containing catalytic systems. The influence o f the extension of the silylation reaction, as well as the use of different silylating agents, have been investigated. Samples were characterised by F TIR, XRF, Si-29-MAS NMR, diffuse reflectance UV-Vis and N-2 adsorption-deso rption isotherms, X-ray photoelectron spectroscopy (XPS) and FTIR of adsorb ed deuteroacetonitrile. The improvement in the catalytic activity achieved has been related to the removal of OH groups by means of calcination or sil ylation treatments. (C) 2000 Elsevier Science B.V. All rights reserved.