Group V metal oxides

Wachs, I.E., Chen, Y., )ehng, ).-M., Briand, LE. and Tanaka, T. (2003) Molecular structure and reactivity of the Group V metal oxides. Catalysis Today,... 

Burlacov, 1., Muller, M., and Heimann, R.B. (2005) Group V metal oxides (V, Nb and Ta) doping of titania coatings by means of suspension plasma spraying. Proceedings 17th International Symposium on Plasma Chemistry, 7-12 August 2005, Toronto, Ontario, Canada. 

More complex in preparation and expensive, hierarchically nanostructured porous group V metal oxides synthesized via a spontaneous autoformation process from alkoxide precursors were used as supports for palladium in total oxidation of toluene (Figure 18.8) [40]. In addition to the effect of the support cation, multimodal porosities of these supports facilitate both the dispersion of the noble metal nanoparticles and the internal transport of the substrates. 

Group V metals oxides - effect of preparation method Gold was introduced into group V metal oxides (V2O5,... 

These reactions involve the oxidation of the phosphine and reduction of the Group V metal trifluoride to the metal. 

Metal oxides of the Group V metals such as tetraalkyltitanate esters, sodium alkoxy titanates, and alkaline earth salts of weak acids are among some other catalysts used to give polyesters without dehydration to the ether or olefin. The Tyzor titanates of DuPont are useful for this application. 

Nitrogen is unusual in forming so many oxides. The acidity of the Group V oxides falls from phosphorus, whose oxides are acidic, through arsenic and antimony whose oxides are amphoteric, to the basic oxide ofbismuth. This change is in accordance with the change from the non-metallic element, phosphorus, to the essentially metallic element, bismuth. The +5 oxides are found, in each case, to be more acidic than the corresponding + 3 oxides. 

Meta/ Oxides. The metal oxides aie defined as oxides of the metals occurring in Groups 3—12 (IIIB to IIB) of the Periodic Table. These oxides, characterized by high electron mobiUty and the positive oxidation state of the metal, ate generally less active as catalysts than are the supported nobel metals, but the oxides are somewhat more resistant to poisoning. The most active single-metal oxide catalysts for complete oxidation of a variety of oxidation reactions are usually found to be the oxides of the first-tow transition metals, V, Cr, Mn, Fe, Co, Ni, and Cu. 

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