Titanium oxides, synthesis

Wang Y, Tang X, Lin L, Huang W, Haochen Y, Gedanken A (2000) Sonochemical synthesis of mesoporous titanium oxide with wormhole-like framework structures. Adv Mater 12 1183-1186... 

The key effect of oxide supports on the catalytic activities of metal particles is exerted through the interface between oxides and metal particles. The key objective of this study is to develop synthesis methodologies for tailoring this interface. Here, an SSG approach was introduced to modify the surface of mesoporous silica materials with ultrathin films of titanium oxide so that the uniform deposition of gold precursors on ordered mesoporous silica materials by DP could be achieved without the constraint of the low lEP of silica. The surface sol-gel process was originally developed by Kunitake and coworkers.This novel technology enables molecular-scale control of film thickness over a large 2-D substrate area and can be viewed as a solution-based... 

Hydrogen peroxide and alkyl hydroperoxides are important oxidants in organic synthesis, but they usually need to be activated by catalysts such as tungsten, molybdenum, and titanium oxides. Heteropoly compounds are good catalysts for oxygenation of olefins or paraffins and oxidative cleavage of vic-diols. 

In the following sections some examples are given of the ways in which these principles have been utilized. The first example is the use of these techniques for the low temperature preparation of oxide ceramics such as silica. This process can also be used to produce alumina, titanium oxide, or other metal oxides. The second example describes the conversion of organic polymers to carbon fiber, a process that was probably the inspiration for the later development of routes to a range of non-oxide ceramics. Following this are brief reviews of processes that lead to the formation of silicon carbide, silicon nitride, boron nitride, and aluminum nitride, plus an introduction to the synthesis of other ceramics such as phosphorus nitride, nitrogen-phosphorus-boron materials, and an example of a transition metal-containing ceramic material. 

Ceramic and semiconductor thin films have been prepared by a number of methods including chemical vapor deposition (CVD), spray-coating, and sol-gel techniques. In the present work, the sol-gel method was chosen to prepare uniform, thin films of titanium oxides on palladium Titanium oxide was chosen because of its versatility as a support material and also because the sol-gel synthesis of titania films has been clearly described by Takahashi and co-workers (22). The procedure utilized herein follows the work of Takahashi, but is modified to take advantage of the hydrogen permeability of the palladium substrate. Our objective was to develop a reliable procedure for the fabrication of thin titania films on palladium, and then to evaluate the performance of the resulting metalloceramic membranes for hydrogen transport and ethylene hydrogenation for comparison to the pure palladium membrane results. 

Magnesium titanate. A detail investigation of mechanochemical synthesis of magnesium titanate from anhydrous and hydrated magnesium and titanium oxides for preparing the ceramics of the highest quality was... 

The authors [46] investigated the effect of mechanical activation on the synthesis of calcium titanate starting from anhydrous and hydrated calcium and titanium oxides. 

A detailed investigation of soft mechanochemical synthesis of aluminium titanate was described in [60]. The data obtained in this study are the evidence of the formation of amorphous hydrated aluminium titanium compounds at the initial stages. These compounds are stable till 450-700°C at higher temperature they decompose to give aluminium and titanium oxides which form dispersed aluminium titanate at 1340°C. 

The known methods of ZrsTi7024 synthesis include long high-temperature treatment of a mixture of zirconium and titanium oxides at 1500°C for 4 h in air. 

Fujii H., Ohtaki M., Eguchi K., Synthesis and photocatalytic activity of lamellar titanium oxide formed by surfactant bilayer templating, J. Am. Chem. Soc. 120 (1998) pp. 6832-6833. 

HTO Catalyst Preparation. Hydrous titanium oxide ion exchangers are amorphous inorganic compounds synthesized in the form of salts of weak acids represented by the empirical formula C(TixOyHz)n, where C is an exchangeable cation. HTO catalysts can be prepared by a technique that consists of synthesis of sodium hydrous titanate ion exchange material followed by exchanging active metal ions for the sodium. The synthesis involves three steps ... 

Titanium oxides have been extensively studied for photocatalytic applications and several examples of Ti02-zeolite composites have also been examined. Sample preparation involved ion exchange or impregnation of titanium aimnonium oxalate on zeolite Y followed by calcination at 450 °C. TS-1, Ti-MCM-41 and Ti-MCM-48 were prepared by hydrothermal synthesis [157]. UV irradiation (260-290 nm) of the catalyst in the presence of a mixture of gas-phase CO2 and H2O led to the for-... 

In the present study, highly dispersed titanium oxides included within the zeolite cavities (Ti-oxide/Y-zeolite) and framework (Ti-MCM-41,-48) were prepared using an ion-exchange method and hydrothermal synthesis to be used as photocatalysts for the reduction of CO2 with H2O at 328 K. The characterization of these catalysts by means of in situ photoluminescence, diffuse reflectance absorption, XAFS (XANES and FT-EXAFS), and ESR measurements have been carried out and special attention has been focused on the relationship between the structure of the titanium oxide species and the reaction selectivity in the photocatalytic reduction of CO2 with H2O to form CH3OH. 

Y.Q. Wang, X.H. Tang, L.X. Yin, W.P. Huang, Y.R. Hacohen, and A. Gedanken, Sono-chemical Synthesis of Mesoporous Titanium Oxide with Wormhole-like Framework Structures. Adv. Mater, 2000, 12, 1183-1186. 

A. Tuel, L. G. Hubert-Pfalzgraf, Nanometric monodispersed titanium oxide particles on mesoporous silica synthesis, characterization, and catalytic activity in oxidation reactions in the liquid phase, /. Catal. 217 (2003) 343. 

Titanium(IV) sulfide, synthesis 23 Nitrogen (IV) oxide, synthesis 24 Uranyl chloride, synthesis 41 Anhydrous metal chlorides, synthesis 43... 

Propyloxyphenylazo) benzoic acid Ti(0-nBu)4 toluene+EtOH then water QCM sensor, ultrathin films of titanium oxide gel prepared by surface sol-gel synthesis [128]... 

The technological potential of titanium oxide has tremendously increased due to enhancement in functional properties, when present in nanocrystalline form, and suitability for solar cell, photochemical, and optical applications. The most widely reported precursors for the synthesis of TiOz particles and films are titanium halides... 

Campion, J, F., Payne, D. A., Choe, H. K., Maurin, J. K., and Wilson, S. R., Synthesis of bimetallic barium titanium alkoxides as precursors for electrical ceramics. Molecular structure of the new barium titanium oxide alkoxide Ba4Tii30i2(OC2H40Me)24, Inorg. Chem., 30, 3245 (1991). 

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