Evidence of solid-solid transformations during the TS-1 crystallization from amorphous wetness impregnated SiO2TiO2 xerogels

Silica–Titania mixed Oxides: Si–O–Ti Connectivity, Coordination of Titanium, and Surface Acidic Properties

“…This can be rationalized in terms of the decomposition of residual organic groups during heat treatment which would result in the breaking and rearrangement of chemical bonds and additional Si-O-Ti linkages are therefore produced. The value (R) drops to 0.46 after calcination at 550°C and then continuously decreases with the increase in [25,28,33]. X-ray diffraction is well known as one of the most powerful techniques for characterizing the structural properties of crystalline solids.…”

“…On the other hand, a broad range of spectroscopic methods have been applied for structural characterization but the results are far less informative than in the case of well-defined, crystalline Ti-substituted zeolites [24]. It is commonly accepted that there is a limit to the proportion of Ti atoms that can be effectively incorporated into the zeolite framework [25]. For SiO 2 -TiO 2 mixed oxides, however, the maximum titanium content that can enter by substitution into the silicon sites remains an important matter seldom discussed.…”

Characterization of adsorptive and hydrophobic properties of silicalite-1, ZSM-5, TS-1 and Beta zeolites by TPD techniques

“…TS-1 zeolite was prepared following a literature procedure based on the hydrothermal treatment of a wetness impregnated SiO 2 -TiO 2 xerogel [11]. This xerogel was prepared through a two-step sol-gel method with TEOS and TNBT as Si and Ti sources, respectively.…”

Epoxidation of Cyclohexene over Crystalline and Amorphous Titanosilicate Catalysts

“…Preparation of TS-1 is usually carried out under hydrothermal conditions using a range of titanium and silicate sources; Taramasso et al have established a specific method for producing TS-1 catalysts [4]. More recently Serrano and co-workers developed a method of converting a dried gel into TS-1 or zeolite b [5][6][7]. This precursor gel can be prepared using a variety of methods [5,6,[8][9][10].…”

“…More recently Serrano and co-workers developed a method of converting a dried gel into TS-1 or zeolite b [5][6][7]. This precursor gel can be prepared using a variety of methods [5,6,[8][9][10]. Here we report a simple procedure to prepare a co-precipitated gel (cogel) containing a specific Si/Ti ratio and subsequent transformation of this cogel into crystalline TS-1 catalysts.…”