Abstract: An inorganic SiO2-TiO2 precursor havingSi-O-Tibonds similar to those present in titaniumsilicate molecular sieve was prepared through spontaneous dispersion of Ti(SO4)2 on amorphous porous silica by thermal treatment. A TS-1 molecular sieve was then synthesized successfully using the inorganic SiO2-TiO2 precursor by hydrothermal crystallization templated by tetrapropylammonium hydroxide. Characterization usingX-raydiffraction, Fourier transform infrared spectroscopy, and ultraviolet-visible absorption spectroscopy showed that a higher proportion of titanium species in the precursor withSi-O-Tibonds was incorporated into the TS-1 framework during the crystallization process, while the titanium species as a bulk TiO2 phase remained unchanged. Conditions affecting the catalytic performance of TS-1 were investigated in detail. The results indicated that the proper conditions were that the treatment temperature for precursor was about 450 ℃, the molar ratio of silica to titanium was 40, the crystallization temperature was about 160-170 ℃, and the crystallization time was about 48-72 h. TS-1 prepared under the above conditions showed that the activity for hydroxylation of phenol was comparable to TS-1 made by the classical method.

Key words: TS-1, spontaneous dispersion, silica, titania, precursor, phenol, hydroxylation