For vanadium oxide

Although much of the V NMR has been performed on model systems or catalytic materials containing vanadium, 29 >30 compounds such as V2O5 or VOPO4 are used in both the catalysis and lithium battery fields, and many of the results can be used to help elucidate the structures of vanadium-containing cathode materials. V NMR spectra are sensitive to changes in the vanadium coordination number and distortions of the vanadium local environments from regular tetrahedra or octahedra. >33 5>V isotropic chemical shifts of between —400 and —800 ppm are seen for vanadium oxides, and unfortunately, unlike... 

CVD routes to vanadium oxide phases have employed a limited number of metal-organic precursors. VO(acac)2 is the most widely used, and oxide films have been deposited from it by low pressure MOCVD and PECVD. Other precursor for vanadium oxide film growth include VO(OiPr)3 and VO(OEt)3. ... 

Up to now, theoretical work on molybdenum oxide surfaces has been restricted to only few periodic slab as well as local cluster studies on the single valence oxide surfaces Mo03(010), (100) and MoO2(011). As for vanadium oxide, there is very little experimental information on quantitative microscopic details of these complex surfaces despite their importance concerning catalytic applications. The following discussion of theoretical results will be based exclusively on cluster studies that have yielded rather detailed microscopic insight. 

Vanadium oxide is used as an industrial catalyst. The percent composition of this oxide is 56.0% vanadium and 44.0% oxygen. Determine the empirical formula for vanadium oxide. 

Table 4 shows the results for the best LSD potential of Vosco, Wilk and Nusair [12] (DFT/L) compared with experiment [21] as well as with other theoretical extensive configuration interaction and coupled-pair functional method [23], where available. Four quintets, one doublet and two sextet states are included in the table. The overall impression which arises from inspection of numbers is that the LCGTO-LSD method works for vanadium oxide even better than could be expected for such a difficult example. Equilibrium bond distances approach the experimental values very closely, similarly to other spectroscopic constatnts even though they have been obtained from a very simple polynomial fit to an approximate, few-point curve. As a rule, the... 

Methylpyridines are easily converted into the corresponding nitriles. The ammoxidation of 3-methylpyridine to nicotinonitrile has been particularly extensively investigated, mainly because of the importance of the nitrile as precursor of vitamins. The catalysts used are mostly vanadium-containing oxides, e. g. vanadium-titanium oxide [86], vanadium-zirconium oxide [87], or multicomponent systems [30,88]. Yields of more than 90% at nearly complete conversion were recently reported (e. g. 100% selectivity for vanadium oxide on titania (anatase) catalysts with V2O5 loading < 3.4 mol% [89]. 

It may be seen from comparison of results on ethylene oxidation over silver and vanadium pentoxide that with both catalysts the oxidation of unsaturated hydrocarbons will proceed by the same mechanism. C02 generation is not accelerated in the presence of aldehydes and these cannot be intermediates in ethylene combustion. When aldehydes are introduced into the reactant mixture, the ratio of ethylene oxide to C02 formation rates undergoes a change, due to strong adsorption of aldehydes on the catalyst surface. Ethylene oxide will form on silver and is in fact absent on vanadium oxides. It was shown experimentally that the absence of acetaldehyde and formaldehyde in the products of oxidation over silver, and the low absolute content of these substances for vanadium oxides is due to the fact that they are not formed at all, or formed at a low rate, and not to their oxidation or decomposition. 

These results were compared to those obtained for vanadium oxide supported on Ga20s and MgO with comparable vanadium content. It was found that V-Mg-O-materials performed catalytically better and the V-Ga-O-materials performed worse than the V-Mg-Ga-O mixed metal oxides supported on AI2O3. Table 2 presents the catalytic performance of the best catalytic materials from V-Mg-Ga, V-Mg-0 and V-Ga-O solid material libraries. 

Rule 5. Production optimization. This can be developed only after the previous stages have been completed. Sometimes entirely new fabrication technologies have to be developed for a novel material but in this case that does not appear to be necessary. Established sol-gel methods for vanadium oxide can be easily scaled up and pigments can be dispersed in it by making suitable particles in the gas phase with a coating that improves adhesion if necessary. 

Maximum capacitance of over 1300 F.gr is observed at low scan rates, and at higher scan rates of 100 mV.sec performance still exhibits 550 F.g . This is much better than other reported values (350 F.gr at 5 mV.sec" ) for vanadium oxide [95]. High scan rates of 2 V.sec for the vanadium nitride electrode still yield 190 F.g indicating that vanadium nitride is capable of high power density. Stability issues due to dissolution of the oxide layer caused a large decrease in original capacitance after 1000 cycles. However, by controlling the pH of the electrolyte, stable capacitance of 400 F.g- was observed for over 1000 cycles on the vanadium nitride electrodes [95]. 

Table 13.2 Acetaldehyde (AC) rates from ethanol per metal atom and acetaldehyde selectivity for vanadium oxide catalysts on different supports at 180 °C. ...

Patterson and coworkers [5-18] have reported detailed liuninescence studies of selected transition metal complex ions in a varietjr of different environments such as in single crystals, in host crystals and on surfaces. For example, for vanadium oxide on a Si02 substrate the vanadium oxide (d ) is present in low concentrations on the substrate and detailed information can be obtained from the luminescence spectra about the vanadium oxide system [5]. This is a case where charge transfer transitions are present. This d° system is the first example to be discussed in Sect. 3. 

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