Nitric oxide adsorbed

In addition to reactive oxygen species, nitric oxide may be a potential mediator of sihca-induced toxicity (Castranova et al. 1996). Nitric oxide adsorbed readily to DQ12 quartz (Robertson et al. 1982). At room temperature it remained adsorbed for up to several weeks. Thermal desorption of NO was much lower (43 %) than of NOj (67 %). Vallya-THAN et al. (1997) studied the kinetic clearance of instilled stable nitroxide radicals (2,2,6,6-tetra-methyl piperidine N-oxyl) and showed an oxidative stress in adult male Sprague-Dawley rats exposed to 10 mg Min-U-Sil quartz <5 im. The generation of reactive oxygen species increased by sihca was associated with enhanced levels of superoxide dismu-tase (P<0.05) and lipid peroxidation. 

Nitric oxide adsorbed on AI2O3 or on AFOs-supported palladium, forms (N0)2, with VsNO at 1871 cm , VasNO at 1761 cm . An ab initio calculation of the vibrational wavenumbers for ONNO+, suggesting that VasNO should be near 1600 cm . ... 

Terenin, A., Roev, L. (1959). Infra-red spectra of nitric oxide adsorbed on transition metals, their salts and oxides, Spectrvchim. Acta, 11,946-957. 

Figure 8.20 Nitrogen Is and oxygen Is X-ray photoelectron spectra of nitric oxide (NO) adsorbed on an iron surface. 1, Fe surface at 85 K 2, exposed at 85 K to NO at 2.65 x 10 Pa for 80 s 3, as for 2 but exposed for 200 s 4, as for 2 but exposed for 480 s 5, after warming to 280 K. (Reproduced, with permission, from Kishi, K. and Roberts, M. W., Proc. R. Soc. Land., A352, 289, 1976)...

The vapor-phase process of SocifitH Chemique de la Grande Paroisse for production of nitroparaffins employs propane, nitrogen dioxide, and air as feedstocks (34). The yields of nitroparaffins based on both propane and nitrogen dioxide are relatively high. Nitric oxide produced during nitration is oxidized to nitrogen dioxide, which is adsorbed in nitric acid. Next, the nitric dioxide is stripped from the acid and recirculated. 

A Japanese group reacted iron vapor with nitric oxide at 77 K (6). Two different species were observed, with Pno at 1800 and 1720 cm , that were assigned as NO species adsorbed on oxidized and metallic iron, respectively. Although no evidence was presented as to the nu-clearity of the products, the authors considered the species to be models for the chemisorption of NO on iron surfaces. 

The major contributions of the Co sites in CoSx-MoSx/NaY to the HYD and HDS reactions were corroborated by a FTIR study of NO adsorption. Figure 7 shows the IR spectra of NO adsorbed on CoSx/NaY (2.1Co/SC) and CoSx-MoSx/NaY (2.1Co 2.1Mo/SC). Nitric oxide... 

The catalytic activity of ln/H-ZSM-5 for the selective reduction of nitric oxide (NO) with methane was improved by the addition of Pt and Ir which catalyzed NO oxidation, even in the presence of water vapor. It was also found that the precious metal, particularly Ir loaded in/H-ZSM-5 gave a low reaction order with respect to NO, and then showed a high catalytic activity for the reduction of NO at low concentrations, if compared with ln/H-ZSM-5. The latter effect of the precious metal is attributed to the enhancement of the chemisorption of NO and also to the increase in the amount of NO2 adsorbed on in sites. 

A Langmuir-Hinshelwood reaction rate model for the reaction between an adsorbed nitric oxide molecule and one adjacently adsorbed hydrogen molecule is described by ... 

Kittrell et al. (1965a) considered three models for the description of the reduction of nitric oxide. The one given in Chapter 4 corresponds to a reaction between one adsorbed molecule of nitric oxide and one adsorbed molecule of hydrogen. This was done on the basis of the shape of the curves passing through the plotted data. 

The iron complex (23) adsorbed on graphite electrode surfaces is an active catalyst for the electroreduction of both nitrite and nitric oxide to yield NH2OH and NH3, as demonstrated by rotating ring-disk electrode voltammetry experiments.341... 

The NO spectrum has now been studied for the molecule adsorbed on ZnO, ZnS (18), 7-AI2O3, silica-alumina, silica-magnesia (20), an A-type zeolite (97), H-mordenite (98), and a variety of Y-type zeolites including NaY (19), MgY, CaY, BaY, SrY (81), decationated-Y (19), ScY, LaY, and A1HY (99). The nitric oxide molecule has mainly been used as a... 

This mode of hyperfine interaction will become important only when the impaired electron is able to partially occupy a low-lying excited state (AE small), and the ground state has orbital angular momentum (L 0). The adsorbed nitric oxide molecule and the superoxide ion with 170 are typical examples where hyperfine coupling via spin-orbit interaction may be observed. 

G.C. Zhao, X.W. Wei, and Z.S. Yang, A nitric oxide biosensor based on myoglobin adsorbed on multi-walled carbon nanotubes. Electroanalysis 17, 630-634 (2005). 

The advantages of electron spectroscopy for the study of adsorbed diatomic molecules are illustrated by reference to the adsorption of carbon monoxide, nitrogen, nitric oxide, and oxygen on different metal surfaces. 

Clearly the molecular events with iron were complex even at 80 K and low NO pressure, and in order to unravel details we chose to study NO adsorption on copper (42), a metal known to be considerably less reactive in chemisorption than iron. It was anticipated, by analogy with carbon monoxide, that nitric oxide would be molecularly adsorbed on copper at 80 K. This, however, was shown to be incorrect (43), and by contrast it was established that the molecule not only dissociated at 80 K, but NjO was generated catalytically within the adlayer. On warming the adlayer formed at 80 K to 295 K, the surface consisted entirely of chemisorbed oxygen with no evidence for nitrogen adatoms. It was the absence of nitrogen adatoms [with their characteristic N(ls) value] at both 80 and 295 K that misled us (43) initially to suggest that adsorption was entirely molecular at 80 K. 

Non-noble metals such as Ni, Co, Mo, W, Fe, Ag and Cu have been added to zeolites for use in catalysis. In addition to CO, nitric oxide (NO) has been shown to be a good adsorbate for probing the electronic environment of these metals. When NO chemisorbs on these metals, it can form mononitrosyl (M-NO) and dinitrosyl species (ON-M-NO). The monontrosyl species has a single absorption band and the dinitrosyl species has two bands due to asymmetric and symmetric vibrational modes of the (ON-M-NO) moiety. Again, there have been many studies reported in the literature on the use of NO and/or CO adsorption on non-noble metals supported on zeolites and they are too numerous to list here. Several examples have been selected and summarized to provide the reader with the type of information that can be provided by this method. 

Photooxidation of chlorobenzene in air containing nitric oxide in a Pyrex glass vessel and a quartz vessel gave 3-chloronitrobenzene, 2-chloro-6-nitrophenol, 2-chloro-4-nitrophenol, 4-chloro-2-nitro-phenol, 4-nitrophenol, 3-chloro-4-nitrophenol, 3-chloro-6-nitrophenol, and 3-chloro-2-nitrophenol (Kanno and Nojima, 1979). A carbon dioxide yield of 18.5% was achieved when chlorobenzene adsorbed on silica gel was irradiated with light (A. >290 nm) for 17 h. The sunlight irradiation of chlorobenzene (20 g) in a 100-mL borosilicate glass-stoppered Erlenmeyer flask for 28 d yielded 1,060 ppm monochlorobiphenyl (Uyeta et al., 1976). 

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