Vanadium-containing catalysts

Oiganometallic usage is shown in the piepaiation of titanium- oi vanadium-containing catalysts foi the polymerisation of styrene or butadiene by the reaction of dimethyl sulfate with the metal chloride (145). Free-radical activity is proposed for the quaternary product from dimethylaruline and dimethyl sulfate and for the product from l,l,4,4-tetramethyl-2-tetra2ene and dimethyl sulfate (146,147). 

SAR [Sulfuric Acid Recovery] A process for purifying and concentrating used sulfuric acid for re-use. The acid is heated with oxygen at 1,040°C to convert the acid to sulfur dioxide. This is then oxidized over a vanadium-containing catalyst to sulfur trioxide, which is dissolved in fresh sulfuric acid to give 98 percent acid. Developed by L Air Liquide and ICI. First demonstrated in 1991 at a methyl methacrylate plant in Taiwan. 

Many different spectroscopic methods have been applied to the study of vanadium-containing catalysts. The results of these investigations by some of the most frequently applied methods are reviewed in this section. 

Methanol Oxidation. - The selective oxidation of methanol to formaldehyde by vanadium-containing catalysts has been widely studied even though in practice only iron molybdate and Ag catalysts are used for this reaction. 

Xe of adsorbed xenon 602 Pt of supported catalyst 604 ° T1 of thallium-containing Be of beryllium-substituted V of vanadium-containing catalysts 649 Ga of gallium-containing 656 La of lanthanum-substituted 677... 

Bruckner, A. (2006). Spin-Spin Exchange in Vanadium-Containing Catalysts Studied by In Situ EPR A Sensitive Monitor for Disorder-Related Activity, Top. Catal., 38, pp. 133-139. 

Lopez Nieto, J., Concepcion, P., Dejoz, A., et al. (2000). Selective Oxidation of n-Butane and Butenes over Vanadium-Containing Catalysts, 7. Catal, 189, pp. 147-157. 

Martin, A., Bentrup, U., and Wolf, G.-U. The effect of alkali metal promotion on vanadium-containing catalysts in the vapour phase oxidation of methyl aromatics to the corresponding aldehydes. Catal. A Gen. 2002, 227, 131-142. 

Tessier, L., Bordes, E., and Gubelmann-Bonneau, M. Active species on vanadium containing catalysts for the selective oxidation of ethane to acetic acid. Catal Today 1995, 24, 335-340. 

Martin, A. and Ltlcke, B. Ammoxidation and oxidation of substituted methyl aromatics on vanadium-containing catalysts. Catal Today 2000, 57, 61-70. 

Lopez Nieto, J.M., Concepcion, R, Dejoz, A., Knozinger, H., Melo, F., and V quez, 1. Selective oxidation of -butane and butenes over vanadium-containing catalysts. J Catal. 2000, 189, 147. 

The result of the NH3 oxidation is that the NH3/NO ratio will change from 1 at lower temperatures, to a value >1 at higher temperatures. In fact, tins is what has been observed for vanadium-containing catalysts at temperatures >300°C. 

The reaction rate is proportional with the vanadium content, thus vanadiinn is the active component in the comercial VTT catalyst. The observed values for the activation energy for the NO and NO/NOj reduction (table 3 and 4) indicates that the same active sites are present in the vanadium containing catalysts VTT, V/Ti02 and VOS. 

K. ScheureU and E. Kemnitz, Amorphous aluminium fluoride as new matrix for vanadium containing catalysts, J. Mater. Chem., 15,4845-4853 (2005). 

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