Titanium oxidation with

Alkali Metal Titanates. Alkali metatitanates may be prepared by fusion of titanium oxide with the appropriate alkah metal carbonate or hydroxide. Representative alkah metal titanates ate hsted in Table 14. The alkah metal titanates tend to be more reactive and less stable than the other titanates, eg, they dissolve relatively easily in dilute acids. 

These batteries are new systems which use a lithium-manganese composite oxide for the active material of the positive electrode a lithium-titanium oxide with a spinel... 

A number of metal oxides are known to form nonstoicbiometric compounds, in which the ratios of atoms that make up the compound cannot be expressed in small whole numbers. In the crystal structure of a nonstoichiometric compound, some of the lattice points where one would have expected to find atoms are vacant. Transition metals most easily form nonstoichiometric compounds because of the number of oxidation states that they can have. For example, a titanium oxide with formula TiO, I( is known, (a) Calculate the average oxidation state of titanium in this compound. 

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... 

From the above results, the surface structure appears to be S04 combined with Zr elements in the bridging bidentated state, as Okazaki et al. proposed in the case of titanium oxide with sulfate ion (155, 156). The double-bond nature of the complex is much stronger compared with that of a simple metal sulfate thus, the Lewis acid strength of Zr4+ becomes remarkably stronger by the inductive effect of S = O in the complex, as illustrated by arrows in the previous scheme. If water molecules are present, the Lewis acid sites are converted to Bronsted acid sites (129, 151, 157). 

Wang et al. (18) have studied binary and ternary mixtures of titanium oxide with zirconium oxide, vanadium oxide and iron oxide, among others. They reported that the by-products are produced in small amounts. Some mixtures are as active or more active than the iron oxide catalyst but are less selective. These researchers noted that in addition to the aforementioned reactions, reactions 3 to 5, the following reactions are significant ... 

Change in the selectivity patterns of transition metal ion/H+ systems has been encountered with the amorphous and anatase types of hydrous titanium oxides with different crystallinities [24]. Potassium titanate, KjO nXi02 (n = 2-4), in particular, exhibits a layered structure. Fibrous titanic acid, H2Ti409 nHjO, is obtained by acid treatment of fibrous K2Ti409 nH20 and shows higher selectivity for K, Rb and Cs than the amorphous titanic acid [206]. 

Wilson JN, Senanayake SD, Idriss H (2004) Carbon coupling on titanium oxide with surface defects. Surf Sci L23L562... 

Derivation Direct combination of titanium with hydrogen, reduction of titanium oxide with calcium hydride in the presence of hydrogen above 600C. 

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. 

Transient terahertz spectroscopy Time-resolved terahertz (THz) spectroscopy (TRTS) has been used to measure the transient photoconductivity of injected electrons in dye-sensitised titanium oxide with subpicosecond time resolution (Beard et al, 2002 Turner et al, 2002). Terahertz probes cover the far-infrared (10-600 cm or 0.3-20 THz) region of the spectrum and measure frequency-dependent photoconductivity. The sample is excited by an ultrafast optical pulse to initiate electron injection and subsequently probed with a THz pulse. In many THz detection schemes, the time-dependent electric field 6 f) of the THz probe pulse is measured by free-space electro-optic sampling (Beard et al, 2002). Both the amplitude and the phase of the electric field can be determined, from which the complex conductivity of the injected electrons can be obtained. Fitting the complex conductivity allows the determination of carrier concentration and mobility. The time evolution of these quantities can be determined by varying the delay time between the optical pump and THz probe pulses. The advantage of this technique is that it provides detailed information on the dynamics of the injected electrons in the semiconductor and complements the time-resolved fluorescence and transient absorption techniques, which often focus on the dynamics of the adsorbates. A similar technique, time-resolved microwave conductivity, has been used to study injection kinetics in dye-sensitised nanocrystalline thin films (Fessenden and Kamat, 1995). However, its time resolution is limited to longer than 1 ns. 

In this paper, we wish to report on the selective oxidation of 5-hydroxymethylfurfural to 2,5-furan-dicarboxaldehyde using vanadium oxide supported on titanium oxide with different vanadium loadings. If we take into account the large differences in the activation energies reported over V2O5 in the oxidation sequence benzyl alcohol --> benzaldehyde (Eg = 26 kJ/mol) and benzaldehyde > benzoic acid (Eg = 55 kJ/mol) [10], those catalytic systems were then expected to stop at the aldehyde stage by working at low temperatui e. 

Exploration of alkaline earth/metal oxide catalysts and other metal/metal oxide catalysts has been continued at Union Carbide. As an example, after over 350 hours of methane coupling with a 5 wt% barium carbonate on titanium oxide (with ethyl chloride in the feed gas), a C2 yield of 22%, a Cj selectivity of 58%, and an ethylene/ethane ratio of 8 1 were obtained. The coupling catalysts were comparable in selectivity, activity, and Cj yield to the better literature catalysts, but provide hundreds of hours of stable operation in the oxidation of methane to Cj s. These catalysts require the presence of a small amount of halides, either as a catalyst component or as a periodic or continuous additive to the catalyst. The chloride appears to serve three distinct roles, resulting in suppression of carbon dioxide formation, increased rates to Cg products, and higher ethylene-to-ethane product ratios. There have been numerous other recent reports. 

The production of camphene is usually carried out by isomerization of a-pinene over titanium oxide catalysts [3]. These are prepared by treating titanium oxide with an acid in order to obtain a layer of titanic acid on the surface of the oxide [4]. The reaction was reported as showing zero order [4] or a transition from first order at low conversion to zero order above ca. 30% conversion [5]. 

Baldwin et al. (1995) surveyed the effect of various mineral phases on the rate of hydrolysis of the model organophosphate ester p-nitrophenyl phosphate. They found that, normalized for the number of independently determined phosphate adsorption sites, the manganese oxides were most effective in catalysing the hydrolysis reaction, followed by iron and titanium oxides, with a small effect for alumina. No effect was... 

Y. Chena, C. Lee, M. Yeng, H. Chiu, Preparing titanium oxide with various morphologies , Materials Chemistry and Physics, 81, 39 4, (2003). 

X-ray fluorescence has been found to be useful in the quantitation of titanium oxides, with internal standards also being used [35]. The methods all make use of the Ti Ka emission at 2.750 A, and differ in their choice of internal standards. 

Very many papers refer the performance of new photocatalytic materials, mostly based on the doping of titanium oxide with various elements (the role of organic sensitizers for photodegradation should not be underrated, however, and has been reviewed). An even more basic (and vexed) question is which is the most active titania phase and the best particle dimension. A study addressing this point has considered how a commercial nanoparticulate anatase Ti02 was modified by calcination at temperatures ranging from 200 to 800 °C. Under these conditions, the primary particle size... 

Feng X, Ding N, Dong Y et al (2013) A chromium oxide solution modified lithium titanium oxide with mueh improved rate performance. J Mater Chem A 1 15310-15315... 

ZS Hu, JX Dong, GX Chen. Preparation of nanometer titanium oxide with n-butanol supercritical drying. Powder Technol 1999 101 205. 

Titanium oxides with hierarchically meso(micro)-macroporous structure could also be prepared via the spontaneous self-formation phenomenon [137,141,142]. The hierarchically porous titanias can be prepared in acidic or alkaline aqueous solution [137]. Different macroporous structures and macropore sizes were obtained when using different alkoxide precursors and under different pH values. The ethoxide, -propoxide, and n-butoxide alkoxides produced powders with limited and localized macroporosity with irregularity and wide pore size distributions (Figure 32.11e-0 [137]. 

CE Bamberger, GM Begun, DE Heatherly. Reaction of titanium oxide with sodium cyanide at 1000 °C. React Solids 3 165, 1987. 

The localization can be broken down when boron forms metallic borides. These are often metallic conductors, and can be thought of as alloys. Titanium diboride, TiB2, for example, is best made by heating boric and titanium oxides with carbon ... 

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