Nitrogen oxides in air

A similar device with Nasicon solid electrolyte Na3Sc(P04)3 is used when analyzing the concentration of nitrogen oxides in air. The electrochemical system in this sensor can be formnlated as... 

The danger of explosions dining oxidation of the nitroso compound to perfluoro-ferf-butanol with nitrogen oxides and subsequent hydrolysis, was reduced by working in a flow system at 160-210°C with 8-10% of nitrogen oxides in air, and using cone, sulfuric acid for hydrolysis. 

Photolytic. Sunlight irradiation of 2-methylphenol and nitrogen oxides in air yielded the following gas-phase products acetaldehyde, formaldehyde, pyruvic acid, peroxyacetyl nitrate, nitrocresols, and trace levels of nitric acid and methyl nitrate. Particulate phase products were also identified and these include 2-hydroxy-3-nitrotoluene, 2-hydroxy-5-nitrotoluene, 2-hydroxy-3,5-dinitrotoluene, and tentatively identified nitrocresol isomers (Grosjean, 1984). Absorbs UV light at a maximum wavelength of 270 nm (Dohnal and Fenclova, 1995). 

Kanno, S. and Nojima, K. Studies on photochemistry of aromatic hydrocarbons. V. Photochemical reaction of chlorobenzene with nitrogen oxides in air, Chemosphere, 8(4) 225-232, 1979. 

Nojima. K. and Karmo, S. Stndies on photochenristry of aromaUc hydrocarbons. Vll. Photochemical reaction of p-dichlorobenzene with nitrogen oxides in air, Chemosphere, 9(7/8) 437-440, 1980. 

Photochemical reaction of chlorobenzene with nitrogen oxides in air. Chemosphere 8 225-232. 

We see that the cycle has been completed and that with a relatively small amount of nitrogen oxides, a large amount of pollutants can be produced, Of course, many other reactions are taking place, so do not be misled by the brevity of die preceding discussion it does, however, serve to present, in rough outline, the role of nitrogen oxides in air pollution. 

Concern over the role of nitrogen oxides in air pollution. This has stimulated the development of catalysts for the removal of nitrogen oxides from exhaust gases. Nitric oxide is thermodynamically unstable with respect to decomposition to its elements at 25°C and 1 atm ... 

Automobile exhaust is another source of 2,4- and 2,6-DNPs in air (Nojima et al. 1983). 2,4-DNP is also used as an insecticide, acaricide, and fungicide (HSDB 1994). Therefore, application of this type of pesticide could be a source of 2,4-DNP in air. Photochemical reactions of benzene with nitrogen oxides in air also produce dinitrophenols in the atmosphere (Nojima et al. 1983). Dinitrophenols have been detected in emissions from hazardous waste combustion (James et al. 1984). Dinitrophenols may be present in the aerosol or vapor phase near hazardous waste disposal sites. It has been suggested that the most important origin of dinitrophenols is their formation by photochemical reactions in the atmosphere (Nojima et al. 1983). 

Most of the sampling carried out In the atmosphere is intended for the determination of pollutants or their effects in localized industrial areas or areas devoted to global environmental studies. Only ocassionally (e.g. measurements of boron [19] or nitrogen oxides in air [20]) are these studies aimed at the Identification of the geochemical cycle of some species in the atmosphere. 

The synthesis of nitrogen oxides in air plasma is one of the old timers in plasma technology. This endothermic plasma-chemical process is usually presented simply as... 

Yang D, Ma J, Xu L, Wu M, Wang H. The effect of nitrogen oxides in air on the performance of proton exchange membrane fuel cell. Electrochim Acta 2006 51(19) 4039-44. 

Y. Wang, S.H. Fan, S.L. Wang, Chemiluminescence determination of nitrogen oxide in air with a sequential injection method. Anal. Chim. Acta 541 (2005) 129-134. 

Figure 6.7. Polarization curves for different concentrations of NO . Cell temperature 60°C, H2/air (1.2/3.3) relative humidity H2 95% and air 0% backpressure 1.5 atm [49], (Reprinted from Electrochimica Acta, 51(19), Yang Daijun, Ma Jianxin, Xu Lin, Wu Minzhong and Wang Haijiang, The effect of nitrogen oxides in air on the performance of proton exchange membrane fuel cell, 4039-44, 2006, with permission from Elsevier.)...

UNI 11247 2007 Determination of the catalytic degradation of nitrogen oxides in air by photocatalytic inorganic materials... 

---