화학공학소재연구정보센터
Applied Catalysis A: General, Vol.124, No.2, 391-408, 1995
Preparation of Ts-1 by Wetness Impregnation of Amorphous SiO2-TiO2 Solids - Influence of the Synthesis Variables
TS-1 has been synthesized by wetness impregnation of amorphous SiO2-TiO2 solids with TPAOH solutions and subsequent crystallization under autogenous pressure, the influence of the different variables involved being studied, The SiO2-TiO2 cogel used as raw material has been prepared following a two step (acid-base) sol-gel process which leads to the formation of Si-O-Ti bonds previously to the zeolite crystallization. The titanium content of TS-1 can be controlled through the variation of the raw SiO2-TiO2 composition, although a limit of the Ti/(Ti+Si) X 100 molar ratio around 2.3% in titanium effectively incorporated to the zeolite framework has been observed, even when starting from cogels with low Si/Ti ratios. The size and morphology of the crystals depend on the synthesis variables, small crystallites with 0.2 mu m of diameter being obtained at high TPAOH concentration. The kinetics of TS-1 crystallization by this method is very fast in spite of taking place in static conditions. Thus, pure TS-1 can be achieved at 170 degrees C in just 6 h of synthesis. All TS-1 samples were tested as catalysts for n-hexane oxyfunctionalization, high activities and selectivities being obtained with most of them.