Nitrous oxide decomposition

On the other hand, considering the practical application, slip catalysts are generally required at the outlet of the SCR reactor in order to remove secondary emissions which typically include a certain concentration of ammonia, isocyanic acid (originating from incomplete urea decomposition), nitrous oxide, and nitrohy-drocarbons. ... 

Johnston H S 1951 Interpretation of the data on the thermal decomposition of nitrous oxide J. Chem. Phys. 19 663-7... 

It is advisable to add the sodium nitrite solution, particularly in preparations on a larger scale, through a separatory or dropping funnel with the tip of the stem extending well below the sui-face of the liquid tliis will prevent loss of nitrous acid by surface decomposition into oxides of nitrogen. 

Alkaline solutions of mononitroparaffins undergo many different reactions when stored for long periods, acidified, or heated. Acidification of solutions of mononitro salts is best effected slowly at 0°C or lower with weak acids or buffered acidic mixtures, such as acetic acid—urea, carbon dioxide, or hydroxyl ammonium chloride. If mineral acids are used under mild conditions, eg, dilute HCl at 0°C, decomposition yields a carbonyl compound and nitrous oxide (Nef reaction). 

Unpiotonated hydioxylamine is oxidized rapidly by ozone, / = 2.1 X 10 (39). The reaction of ozone with the lower oxides of nitrogen (NO and NO2) is also rapid and quantitative the end product is nitrogen pentoxide, which is also a catalyst for the decomposition of ozone (45). Nitrous oxide, however, reacts slowly (k < 10 ) (39). Nitrogen-containing anions, eg, nitrite and cyanide, also ate oxidized by ozone (39). Nitrite is oxidized to nitrate (fc = 3.7 X 10 and cyanide is oxidized rapidly to cyanate (fc = 2.6 X 10 (46) and 10 -10 (39)). Cyanate, however, is oxidized slowly. 

When the salt is heated to temperatures from 200 to 230°C, exothermic decomposition occurs (4,21). The reaction is rapid, but it can be controlled, and it is the basis for the commercial preparation of nitrous oxide [10024-97-2]. 

Ammonium nitrate decomposes into nitrous oxide and water. In the solid phase, decomposition begins at about I50°C (302°F) but becomes extensive only above the melting point (I70°C) (338°F). The reaction is first-order, with activation energy about 40 kcal/g mol (72,000 Btii/lb mol). Traces of moisture and Cr lower the decomposition temperature thoroughly dried material has been kept at 300°C (572°F). All oxides of nitrogen, as well as oxygen and nitrogen, have been detected in decompositions of nitrates. 

Nitrous oxide may also be obtained by the controlled reduction of nitrates or nitrites, decomposition of hyponitrites, or thermal decomposition of hydroxylamine. 

The decomposition of nitrous oxide (NjO) to nitrogen and oxygen is preformed in a 5.0 1 batch reactor at a constant temperature of 1,015 K, beginning with pure NjO at several initial pressures. The reactor pressure P(t) is monitored, and the times (tj/2) required to achieve 50% conversion of N2O are noted in Table 3-19. Use these results to verify that the N2O decomposition reaction is second order and determine the value of k at T = 1,015 K. 

The decomposition of nitrous oxide (NjO) to nitrogen and oxygen is represented by... 

Nitrous oxide can be made by the careful thermal decomposition of molten NH4NO3 at about 250°C ... 

PCSs obtained by dehydrochlorination of poly(2-dilorovinyl methyl ketones) catalyze the processes of oxidation and dehydrogenation of alcohols, and the toluene oxidation207. The products of the thermal transformation of PAN are also catalysts for the decomposition of nitrous oxide, for the dehydrogenation of alcohols and cyclohexene274, and for the cis-tnms isomerization of olefins275. Catalytic activity in the decomposition reactions of hydrazine, formic acid, and hydrogen peroxide is also manifested by the products of FVC dehydrochlorination... 

Thermal Decomposition. The therm decompn was studied betw 380 and 430° and found to be homogeneous and apparently 1st order. The products were complex and included nitric oxide, methane, carbon monoxide, and w plus small amts of ethane, ethylene, and nitrous oxide (Ref 23)... 

The stratosphere contains, however, only small amounts--a few tenths of a ppb-of chlorine free radicals of natural origin. They are produced by the decomposition of methyl chloride, CH3Q. The nitrogen oxides (NO and NO2) are more abundant and are produced in the stratosphere by the decomposition of nitrous oxide, N2O. Both CH3CI and N2O are of biological origin these compounds, released at the Earth s surface, are sufficiently stable to reach the stratosphere in significant amounts. 

One-step hydroxylation of aromatic nucleus with nitrous oxide (N2O) is among recently discovered organic reactions. A high eflSciency of FeZSM-5 zeolites in this reaction relates to a pronounced biomimetic-type activity of iron complexes stabilized in ZSM-5 matrix. N2O decomposition on these complexes produces particular atomic oj gen form (a-oxygen), whose chemistry is similar to that performed by the active oxygen of enzyme monooxygenases. Room temperature oxidation reactions of a-oxygen as well as the data on the kinetic isotope effect and Moessbauer spectroscopy show FeZSM-5 zeolite to be a successfiil biomimetic model. 

Nitrous oxide is unstable because it is an endothermic substance. It gives rise to an explosive decomposition if it is heated. 

Copper metal surface area was determined by nitrous oxide decomposition. A sample of catalyst (0.2 g) was reduced by heating to 563 K under a flow of 10 % H2/N2 (50 cm min"1) at a heating rate of 3 deg.min 1. The catalyst was then held at this temperature for 1 h before the gas flow was switched to helium. After 0.5 h the catalyst was cooled in to 333 K and a flow of 5 %N20/He (50 cm3mirr ) passed over the sample for 0.25 h to surface oxidise the copper. At the end of this period the flow was switched to 10 % H2/N2 (50 entitlin 1) and the sample heated at a heating rate of 3 deg.min"1. The hydrogen up-take was quantified, from this a... 

Hart and Henglein [14] also reported the sonolytic decomposition of nitrous oxide in aqueous solutions under pure argon, pure N2O and the mixture of the two gases and reported the formation of species such as N2, O2, N02 and N03 with the maximum yield being in the Ar/N20 mixture in the vol% ratio of 85 15. Although H20 is thermodynamically much more stable than N2O but they postulated that all H20 and N2O molecules in an argon bubble were converted into free radicals in the short time of adiabatic compression phase of the bubble. They proposed a series of free radical reactions for the formation of all these species in aqueous solutions. 

Hart Edwin J, Henglein Amim (1986) Sonolytic decomposition of nitrous oxide in aqueous solution. J Phys Chem 90 5992-5995... 

Hinshelwood and Burk [Proc. Roy. Soc., 106A (284), 1924] have studied the thermal decomposition of nitrous oxide. Consider the following adjusted data at 1030 °K. 

Despite several decades of studies devoted to the characterization of Fe-ZSM-5 zeolite materials, the nature of the active sites in N20 direct decomposition (Fe species nuclearity, coordination, etc.) is still a matter of debate [1], The difficulty in understanding the Fe-ZSM-5 reactivity justifies a quantum chemical approach. Apart from mononuclear models which have been extensively investigated [2-5], there are very few results on binuclear iron sites in Fe-ZSM-5 [6-8], These DFT studies are essentially devoted to the investigation of oxygen-bridged binuclear iron structures [Fe-0-Fe]2+, while [FeII(p-0)(p-0H)FeII]+ di-iron core species have been proposed to be the active species from spectroscopic results [9]. We thus performed DFT based calculations to study the reactivity of these species exchanged in ZSM-5 zeolite and considered the whole nitrous oxide catalytic decomposition cycle [10],... 

Yang, C. C., Cutlip, M. B., and Bennett, C. 0. A study of nitrous oxide decomposition on nickel oxide by a dynamic method. Proc. of the Vth Congr. on Catal., Palm Beach, 1973. 

Decomposition of Nitrous Oxide on Magnesium Oxide Compared to That on Cupric Oxide... 

The decomposition of nitrous oxide over various metal oxides has been widely investigated by many investigators (1-3). Dell, Stone and Tiley (4) have compared the reactivity of metal oxides and shown that in general p-type oxides were the best catalysts and n-type the worst, with insulators occupying an intermediate position. It has been generally accepted (5) that this correlation indicates that the electronic structure of the catalyst is an important factor in the mechanism of the decomposition of nitrous oxide over metal oxides catalysts. The reaction is usually written (4) as... 

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