Hydrogen peroxide decomposition in the presence

Klais, O. (1993). "Hydrogen Peroxide Decomposition in the Presence of Organic Material. A Case Study." Thermochimica Acta 225, 213-22. 

DHAP can be prepared by oxidation of L-glycerol-3-phosphate (L- G3P) catalyzed by glycerophosphate oxidase, coupled with hydrogen peroxide decomposition in the presence of catalase (Scheme 4.5) [14]. More recently, this synthetic route has... 

The formation of halohydrins can be promoted by peroxidase catalysts.465 Recently 466 it has been shown that photocatalysis reactions of hydrogen peroxide decomposition in the presence of titanium tetrachloride can produce halohydrins. The workers believe that titanium(IV) peroxide complexes are formed in situ, which act as the photocatalysts for hydrogen peroxide degradation and for the synthesis of the chlorohydrins from the olefins. The kinetics of chlorohydrin formation were studied, along with oxygen formation. The quantum yield was found to be dependent upon the olefin concentration. The mechanism is believed to involve short-lived di- or poly-meric titanium(IV) complexes. 

Oxygen is prepared by the decomposition of hydrogen peroxide (H202) in the presence of a catalyst (manganese dioxide (Mn02)). The reaction is as follows ... 

The oxidative decomposition of ozonides is further accomplished by their treatment with hydrogen peroxide [97] in the presence of formic acid [95, 99] or acetic acid [102, 103] or with silver oxide and nitric acid [77] (equations 109-112). 

All reactions from simple linear to complex nonlinear ones, sensitive on the presence of considered catalyst, could be used for its characterization. The manipulation with simpler reactions is easier whereas the number of information that can be obtained by complex reactions is richer. Although, our aim here is to examine catalysts by a complex oscillatory reaction, we shall begin the explanations with relatively simple reaction of the homogeneous hydrogen peroxide decomposition in the aqueous solution [6] given by the following reaction scheme ... 

The experiment involves the decomposition of hydrogen peroxide (H2O2) in the presence of a catalyst (an added molecule that speeds the rate of a given reaction), a surfactant (a dishwashing detergent), and a colorant, carried out in a 2L plastic bottle. The catalyst, potassium iodide (KI), speeds up the decomposition reaction, and the evolved O2 gas is captured by the surfactant, which in turn, foams like toothpaste. The foam shoots out of the bottle, and the heat released by the reaction causes the bottle to shrink. The experiment can be used to demonstrate the energy aspect of reactions, and tell about endothermic and exothermic reactions, about gases and their properties, and about Lavoisier and the other discoverers of the O2 molecule. 

Note Although Hydrogen Peroxide undergoes exothermic decomposition in the presence of dirt and other foreign materials, it is safe and stable under recommended conditions of handling and storage. Information on safe handling and use may be obtained from the supplier. 

The oxidase reaction is inhibited by carbon monoxide and by catalase, properties which are characteristic of oxidase-peroxidases, and which suggest that both ferrous iron and hydrogen peroxide participate in the overall reaction. If this is the case, inhibition by catalase may be explained by (1) destruction of hydrogen peroxide necessary to initiate the formation of ferroperoxidase, corresponding to the reduction of ferricatalase to ferrocatalase in the presence of peroxide and an electron donor (752), ) a side reaction in which oxyferroperoxidase is reduced to ferriperoxidase via Complex II (compare Fig. 17), or (S) destruction of peroxidase. In support of the last alternative, it has been observed that the decomposition of peroxide-... 

G-20 Dicarboxylic Acids. These acids have been prepared from cyclohexanone via conversion to cyclohexanone peroxide foUowed by decomposition by ferrous ions in the presence of butadiene (84—87). Okamura Oil Mill (Japan) produces a series of commercial acids based on a modification of this reaction. For example, Okamura s modifications of the reaction results in the foUowing composition of the reaction product C-16 (Linear) 4—9%, C-16 (branched) 2—4%, C-20 (linear) 35—52%, and C-20 (branched) 30—40%. Unsaturated methyl esters are first formed that are hydrogenated and then hydrolyzed to obtain the mixed acids. Relatively pure fractions of C-16 and C-20, both linear and branched, are obtained after... 

MMA onto cellulose was carried out by Hecker de Carvalho and Alfred using ammonium and potassium persulfates as radical initiators [30]. Radical initiators such as H2O2, BPO dicumylperoxide, TBHP, etc. have also been used successfully for grafting vinyl monomers onto hydrocarbon backbones, such as polypropylene and polyethylene. The general mechanism seems to be that when the polymer is exposed to vinyl monomers in the presence of peroxide under conditions that permit decomposition of the peroxide to free radicals, the monomer becomes attached to the backbone of the polymer and pendant chains of vinyl monomers are grown on the active sites. The basic mechanism involves abstraction of a hydrogen from the polymer to form a free radical to which monomer adds ... 

Many reactions that take place slowly under ordinary conditions occur readily in living organisms in the presence of catalysts called enzymes. Enzymes are protein molecules of high molar mass. An example of an enzyme-catalyzed reaction is the decomposition of hydrogen peroxide ... 

The second major discovery regarding the use of MTO as an epoxidation catalyst came in 1996, when Sharpless and coworkers reported on the use of substoichio-metric amounts of pyridine as a co-catalyst in the system [103]. A change of solvent from tert-butanol to dichloromethane and the introduction of 12 mol% of pyridine even allowed the synthesis of very sensitive epoxides with aqueous hydrogen peroxide as the terminal oxidant. A significant rate acceleration was also observed for the epoxidation reaction performed in the presence of pyridine. This discovery was the first example of an efficient MTO-based system for epoxidation under neutral to basic conditions. Under these conditions the detrimental acid-induced decomposition of the epoxide is effectively avoided. With this novel system, a variety of... 

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