Hydrogen peroxide methane

The superacid-catalyzed electrophile oxygenation of saturated hydrocarbons, including methane with hydrogen peroxide (via H302 ) or ozone (via HOs ), allowed the efficient preparation of oxygenated derivatives. 

Vanadium pentoxide and mercuric oxide were used as catalysts for the hydrogen peroxide oxidation of bis(phenylthio)methane to its monooxide 17a31 (equation 5). From the synthetic point of view, it is interesting to note that vanadium pentoxide, in addition to its catalytic action, functions also as an indicator in this reaction. In the presence of hydrogen peroxide, the reaction mixture is orange while in the absence of hydrogen peroxide a pale yellow colour is observed. Thus, it is possible to perform the oxidation process as a titration ensuring that an excess of oxidant is never present. 

C19-0050. What are the half-reactions for these redox processes (a) Aqueous hydrogen peroxide acts on Co, and the products are hydroxide and Co , in basic solution, (b) Methane reacts with oxygen gas and produces water and carbon dioxide, (c) To recharge a lead storage battery, lead(II) sulfate is converted to lead metal and to lead(IV) oxide, (d) Zinc metal dissolves in aqueous hydrochloric acid to give ions and hydrogen gas. 

To test the validity of this hypothesis, a 30% solution of hydrogen peroxide, a good source of hydroxyl radicals, was injected into the reactor during photockalytic methane... 

In the presence of metal catalysts, hydrogen peroxide oxidations proceed in improved yields. The most common catalyst is an iron(II) salt which produces the well-known Fenton system or reagent. Dimethyl sulphoxide is oxidized to the sulphone using this system although a range of unwanted side-products such as methanol and methane are produced Diphenyl sulphoxide does not react using this reagent due to its insolubility and in all cases some iron(III) is formed by other side-reactions. 

Chlorine dioxide Copper Fluorine Hydrazine Hydrocarbons (benzene, butane, propane, gasoline, turpentine, etc) Hydrocyanic acid Hydrofluoric acid, anhydrous (hydrogen fluoride) Hydrogen peroxide Ammonia, methane, phosphine or hydrogen sulphide Acetylene, hydrogen peroxide Isolate from everything Hydrogen peroxide, nitric acid, or any other oxidant Fluorine, chlorine, bromine, chromic acid, peroxide Nitric acid, alkalis Ammonia, aqueous or anhydrous Copper, chromium, iron, most metals or their salts, any flammable liquid, combustible materials, aniline, nitromethane... 

The oxidation procedure is amenable to a number of modifications. The solvent used may be varied carbon tetrachloride, hexane, toluene and dichloro-methane have all been used successfully, although the latter two are the solvents of choice. The most common oxidant is aqueous hydrogen peroxide, but other oxidants such as t-butyl hydroperoxide [4], sodium perborate (Table 1, Entries 18 and 22) and sodium percarbonate [4] have also been employed. It is interesting to note the effect of a change of oxidant. Using alkaline hydrogen peroxide... 

Vanadium-catalyzed hydroxylation of benzene and cyclohexane has also been obtained with in situ generation of hydrogen peroxide from H2/O2 in the presence of palladium. A similar process has been settled for methane oxygenation to methyl trifluoroacetate and formic acid. Monoperoxovanadate, as well as copper hydroperoxides, have been indicated as the active species for the activation of the C—H bond of methane. 

Hydrogen Peroxide, Hydrazine, Nitro-methane, sym-Dinitromethane and Methyl Nitrate in ethanol (Refs 10 23).- Of these only Hydrazine and Hydrogen Peroxide have been used and are being used in practical propulsion systems... 

In a cold bath or in an explosion-proof refrigerator, a solution of 1.3 gm (approximately 0.0035 mole) of crude Y,Y -benzhydrylhydrazine (m.p. 114°-130°C) in a mixture of 40 ml of acetone and 50 ml of ethanol and 1.25 gm (0.0096 mole) of 30% hydrogen peroxide is maintained at 10°-15°C for 8 hr. The solvent is rapidly removed by evaporation under reduced pressure with only moderate warming. The residue is rapidly recrystallized from ethanol. Yield 1 gm (76%), m.p. 115°C dec. (NOTE On melting, azobis(diphenyl-methane) decomposes with loss of nitrogen to form a solid with m.p. 205°-210°C, which has been identified as the expected 1,1,2,2-tetraphenylethane.)... 

Scheme 3 Mechanism of formation of methane in the reaction of V2+ with hydrogen peroxide and DMSO...

It should be mentioned that with superacidic electrophilic oxygenation of methane either to methanol (with protonated hydrogen peroxide) or to formaldehyde (with protonated ozone), the products formed are indeed the protonated products (CH3OH2 and CH2=OH+, respectively), which are protected from further electrophilic oxygenation, which happens only too readily in conventional oxidations. 

Low Temperature Reaction. Reaction in the low temperature regime below 320°C. is of a different character. The products include carbon dioxide and significant quantities of peroxy compounds, as well as carbon monoxide, water, formaldehyde, and methanol, but methane and ethylene are formed only in traces. The peroxy compounds comprise hydrogen peroxide from all three ketones, methyl hydroperoxide from acetone (8) and methyl ethyl ketone (I), and ethyl hydroperoxide from diethyl ketone (1). Methyl ethyl ketone also gives large amounts of peracetic acid (1). 

In the last stages of hydrocarbon oxidation, by both the low and high temperature mechanism, when the oxygen concentration is low, a new phenomenon appears—the pic darret. The methodical study of the reaction of propane and oxygen at various pressures, temperatures, and concentrations indicates three different aspects of the slow oxidation. When the pic d arret occurs, the analysis of some reaction products indicates an increase in the amounts of methane, ethane, acetaldehyde, ethyl alcohol, propyl alcohol, and especially isopropyl alcohol, and a decrease in the formation of hydrogen peroxide and olefin. All these results are explained by radical reactions such as R + R02 (or H02) ROOR - 2 RO oxygenated products and R + R - RR. 

With respect to the untreated Reactor I, the hydrogen peroxide yield was very small, and that of methane, ethylene, carbon monoxide, and acetaldehyde was large. The small ratio of hydrogen peroxide to propylene is possibly caused by the successive decomposition of hydrogen peroxide once formed. With aged Reactor II, the yield of hydrogen peroxide and methanol increased, while that of methane, ethylene, and carbon monoxide decreased significantly. 

Among other reactions, it is worth mentioning the formation of hydrogen chloride in a reaction with methane, molecular hydrogen, or other constituents such as formaldehyde, H2CO, or hydrogen peroxide, H202. An example is... 

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