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Polyoxometalates Keggin type

Fig. 15. Crystal structure of the Keggin-type polyoxometallate ion [PMo427W7.73O40]6. Adapted from (608). Fig. 15. Crystal structure of the Keggin-type polyoxometallate ion [PMo427W7.73O40]6. Adapted from (608).
Various Keggin-type polyoxometalates (POMs) were tested as catalysts for the ODS of gas oil with t-butyl hydroperoxide. Alumina-supported phosphomolybdic acid (H3PMoi2O40) proved to be quite active, yielding sulfur conversion higher than... [Pg.303]

THREE-DIMENSIONAL ORDERED MACROPOROUS HYBRID SILICA MATERIALS FUNCTIONALIZED WITH LACUNARY KEGGIN-TYPE POLYOXOMETALATES PREPARATION AND CHARACTERIZATION... [Pg.249]

Guo Y. H., Yang Y., Hu C. W., Ordered macroporous hybrid silica based on lacunary Keggin-type polyoxometalates preparation, characterization and photochemical behavior, Qn press). [Pg.256]

The current industrial production of methylmethacrylate by the acetone-cyanohydrin process suffers from a number of drawbacks, which make it environmentally unfriendly. In particular, it makes use of a very toxic reactant (HCN) and intermediate (acetone cyanohydrin), and coproduces large amounts of impure ammonium sulphate, contaminated with organic compounds. Among the several alternative synthetic routes which have been proposed, particularly interesting from both the practical and scientific points of view is the single-step oxidation of isobutane to methacrylic acid, intermediate in the synthesis of methylmethacrylate. Several industrial companies have studied this reaction (and the selective oxidation of propane to acrylic acid, as well), and it has been established that the most active and selective catalysts are those which are based on Keggin-type polyoxometalates (POM s), containing phosphorus and molybdenum as the main components [1-18]. [Pg.141]

Sawada, Y. Matsumoto, K. Katsuki, T. Angew. Chem. Int. Ed. 2007, 46, 4559. cat. Keggin-type polyoxometalate... [Pg.340]

Figure 7 Stmcture of phosphomolybdate ion, a Keggin-type polyoxometalate. Figure 7 Stmcture of phosphomolybdate ion, a Keggin-type polyoxometalate.
Ti(IV) monosuhstituted Keggin-type polyoxometalates (Ti-POMs) are stable towards the hydrolysis of Ti-O-W bonds and oxidative degradation. The catalytic oxidation of 3 using H2O2 as the oxidant over Ti-POMs yields 2,3,5-TMHQ (1) and the biphenol (6) as main products (Fig. 16.6). The product distribution depends significantly on the TMP/Ti-POM molar ratio. ... [Pg.391]

Kogan, V., Aizenshtat, Z., Popovitz-Biro, R., et al. (2002). Carbon-Carbon and Carbon-Nitrogen Coupling Reactions Catalyzed by Palladium Nanoparticles Derived from a Palladium Substituted Keggin-Type Polyoxometalate, Org. Lett., 4, pp. 3529-3532. [Pg.620]

Wang,B.,Vyas,R. and Shaik,S. (2007) Preparation Parameter DevelopmentforLayer-by-Layer Assembly of Keggin-Type Polyoxometalates, Langmuir, 23, pp. Ill 20-11126. [Pg.630]

Feng, Y, Han, Z., Peng, J., et al. (2006). Fabrication and Characterization of Multilayer Films Based on Keggin-Type Polyoxometalate and Chitosan, Mater. Lett., 60, pp. 1588-1593. [Pg.630]

Systems based on Keggin-type polyoxometalates (POMs) (phosphomolybdic acid derivatives) have been the most effective and widely used catalysts in gas-phase isobutane selective oxidation research. This Keggin POM catalyst application was hrst claimed in 1981 by Rohm and Haas, and after several catalyst mod-ihcations has been patented by other companies such as Asahi Kasei, Sumitomo, Mitshubishi, etc. However, in addition to a Keggin phosphomolybdate, vanadium must also be present in the anion structure in order to obtain a catalyst effective in the selective oxidation of isobutane. Moreover, the addition of - -3 metal cations to the phosphomolybdate anion increases the thermal stability of the catalyst, significantly minimizing its deactivation. " ... [Pg.805]

Cavani, R, Mezzogori, R., Pigamo, A., et al (2001). Main Aspects of the Selective Oxidation of Isohutane to Methacrylic Acid Catalyzed hy Keggin-Type Polyoxometalates, Catal. Today, 71, pp. 97-110. [Pg.824]

Keggin type polyoxometalate For the design of molecular memories... [Pg.145]

The preparation of cellulose/silica hybrid materials functionalized with Keggin-type polyoxometalates employing sol-gel synthesis tmder mild conditions has been also developed. These bio-based materials were composed by a 37 % of propylamine-modified silica dispersed over cellulosic fibres (56 wt%) and a small... [Pg.72]

Jiang C, Guo Y, Hu C, Wang C, Li D (2004) Photocatalytic degradation of dye naphthol blue black in the presence of zirconia-supported Ti-substituted Keggin-type polyoxometalates. Mater Res Bull 39 251-257... [Pg.105]

See other pages where Polyoxometalates Keggin type is mentioned: [Pg.86]    [Pg.440]    [Pg.440]    [Pg.374]    [Pg.232]    [Pg.258]    [Pg.171]    [Pg.171]    [Pg.316]    [Pg.333]    [Pg.209]    [Pg.402]    [Pg.143]    [Pg.312]    [Pg.188]    [Pg.191]    [Pg.54]    [Pg.86]    [Pg.107]   
See also in sourсe #XX -- [ Pg.86 ]

See also in sourсe #XX -- [ Pg.178 , Pg.374 ]

See also in sourсe #XX -- [ Pg.588 , Pg.805 ]

See also in sourсe #XX -- [ Pg.54 ]



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Keggin-type

Keggin-type polyoxometalates isobutane oxidation

Polyoxometalate

Polyoxometalate Keggin-type

Polyoxometalates

Polyoxometalates types

Polyoxometallate

Polyoxometallates

Supported Keggin-type polyoxometalates

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