Catalyst for oxidation with hydrogen peroxide

B. Supported Mo Catalyst for Oxidation with Hydrogen Peroxide as the Oxidant... 

Solid catalysts may also be used for reactions implying oxidants differ by dioxygen. The most popular case is that of titanium-silicalite catalysts for oxidation with hydrogen peroxide. The active species in the presence of water has been characterised to be a side-on peroxo complex characterised by a Raman-detected 0-0 stretching at 618 cm Upon drying, this species converts into a hydroperoxo species characterised using IR by an 0-0 stretching at 837 cm and a broad OH band at 3400 cm ... 

Neumann R (2004) Polyoxometalates as catalysts for oxidation with hydrogen peroxide and molecular oxygen. In Beller M, Bolm C (eds) Transition metals for organic synthesis, 2nd edn., vol 2, WUey, Weinheim, p 415... 

M. C. A. van Vliet, 1. W. C. E. Arends, R. A. Sheldon, Tertiary arsine oxides Active and selective catalysts for epoxidation with hydrogen peroxide. Tetrahedron Lett. 40 (1999) 5239. 

LARGE PORE TI-BETA ZEOLITE WITH VERY LOW ALUMINIUM CONTENT AN ACTIVE AND SELECTIVE CATALYST FOR OXIDATIONS USING HYDROGEN PEROXIDE... 

The use of molybdenum catalysts in combination with hydrogen peroxide is not so common. Nevertheless, there are a number of systems in which molybdates have been employed for the activation of hydrogen peroxide. A catalytic amount of sodium molybdate in combination with monodentate ligands (e.g., hexaalkyl phosphorus triamides or pyridine-N-oxides), and sulfuric acid allowed the epoxidation of simple linear or cyclic olefins [46]. The selectivity obtained by this method was quite low, and significant amounts of diol were formed, even though highly concentrated hydrogen peroxide (>70%) was employed. 

DeDiox A process for destroying polychlorinated dioxins and furans in flue-gases by catalytic oxidation with hydrogen peroxide. The catalyst is based on silica and the process is operated at 80 to 100°C. Developed by Degussa from 1994. The business was offered for sale in 1998. 

In 2001, Albrecht Berkessel and Nadine Vogl reported on the Baeyer-Villiger oxidation with hydrogen peroxide in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) as solvent in the presence of Brpnsted acid catalysts such as para-toluenesulfonic acid (equation 85) . Under these conditions cyclohexanone could be selectively transformed into the corresponding lactone within 40 min at 60 °C with a yield of 92%. Mechanistic investigations of Berkessel and coworkers revealed that this reaction in HFIP proceeds by a new mechanism, via spiro-bisperoxide 234 as intermediate, which then rearranges to form the lactone. The study illustrates the importance of HFIP as solvent for the reaction, which presumably allows the cationic rearrangement of the tetroxane intermediates. 

GeW12C SiW,2C4 > FeW,20 a BW,20 > CoW)20 > CuWi20 [13, 14]. This property is well reflected in their catalytic activities. For cyclohexene oxidation with hydrogen peroxide, the catalytic activity increased in the order B3+ < Si4+ < C44 < P5+ [25, 26]. Cetylpyridinium salts of HPA can be used as phase-transfer catalysts and catalyze epoxidation of alkenes very efficiently in a two-phase system comprising aqueous H202 and CHCI3 [27]. 

A range of metal catalysts can be employed with peroxygen species for the effective oxidation of sulfur compounds. For example, branched-chain high molecular weight mercaptans are difficult to oxidize with hydrogen peroxide. However, this difficulty is overcome if the reaction is conducted with hydrogen peroxide in the presence of a copper(II) salt.395 The formation of a copper(I) mercaptide followed by its oxidation are believed to be the key steps. 

However, the relatively high enzyme costs form an obstacle to commercialization. Inefficient laccase use is a result of its instability towards the oxidizing reaction conditions. We have recently shown that the stability of the laccase under reaction conditions can be improved by immobilization as a cross-linked enzyme aggregate (see Chapter 9). It has also been shown that a water-soluble iron complex of a sulfonated phthalocyanine ligand is an extremely effective catalyst for starch oxidation with hydrogen peroxide in an aqueous medium [11]. 

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