Catalytic characterization of mesoporous Ti-silica hollow spheres

Titanium-silica hollow spheres (TSHS) with a mesoporous shell were synthesized using an inverse multiple oil-water-oil (O/W/O) emulsion. These novel materials show interesting potential for catalysis. Excellent catalytic performance was found in the epoxidation of cyclohexene with tert-butylhydroperoxide. The investigation of the titanium environment by UV-vis, Raman and FTIR spectroscopy showed that at low Ti loading only isolated species are present and catalytic measurements demonstrated that these species are the active sites for this reaction. At higher loading Ti-O-Ti microdomains are present and they do not exhibit any significant catalytic activity.