O2 reactions

Venkatesh P K, Dean A M, Cohen M H and Carr R W 1999 Master equation analysis of intermolecular energy transfer in multiple-well, multiple-channel unimolecular reactions. II. Numerical methods and application to the mechanism of the C. + O2 reaction J. Chem. Phys. Ill 8313... 

The branching cycle involving the radicals FI, OFl and O in the Fl2 + O2 reaction involves the tliree elementary steps... 

Figure A3.14.7. Example oscillatory time series for CO + O2 reaction in a flow reactor corresponding to different P-T locations in figure A3,14,6 (a) period-1 (b) period-2 (c) period-4 (d) aperiodic (chaotic) trace (e) period-5 (1) period-3.

Johnson B R and Scott S K 1990 Period doubling and chaos during the oscillatory ignition of the CO + O2 reaction J. Chem. Soc. Faraday Trans. 86 3701-5... 

Irvin J A and Dagdigian P J 1980 Chemiluminescence from the Ca(4s3d D) + O2 reaction absolute cross sections, photon yield, and CaO dissociation energy J. Chem. Rhys. 73 176-82... 

J. Mai, W. von Niessen. The CO -(- O2 reaction on metal surfaces. Simulation and mean-field theory The influence of diffusion. J Chem Phys 95 3685-3692, 1990. 

When (TMSlsSiH was treated with a mixture of O2 and O2 (Reaction 32) and the crude products were analyzed by mass spectrometry, similar label... 

The ketenyl radical (HCCO) is a key intermediate in the oxidation of acetylene in flames. It is mainly formed from the O + C2H2 HCCO + H reaction. In lean flames, the HCCO + O2 reaction is the main pathway for decay of HCCO, and this reaction has recently been shown to be the source of prompt CO2 [44, 45]. 

Figure 2.1S. The rate of CO2 formation in the CO + O2 reaction on Pt(l 110) oscillates synchronously with the surface reconstruction, from (1x1) to (1x2), shown in Fig. 2.14. [Adapted from M. Eiswirth, P. Moeller, K. Wetzl, R. Imbihl, and G. Ertl, /. Chem. Phys. 90 (1989) 510.1...

The effects of precious metals on ln/H-ZSM-5 was found not only to simply catalyze NO oxidation but also to enhance NOx chemisorption. It is noted that NO conversion on the lr/ln/H-ZSM-5 exceeded NO2 conversion in NO2-CH4-O2 reaction on in/H-ZSM-5, when the concentration of NOx was decreased [14]. This study shows the catalytic activities of ln/H-ZSM-5 promoted by precious metals for the removal of low concentration NOx and the promotive effects of the precious metal will be discussed. 

Figure 2 shows the effect of NOx concentration on the conversion of NOx reduced by CH4 in the presence of 5% H2O. In the NO-CH4-O2 system, In/H-ZSM-5 showed low catalytic activity in the whole range of NO concentration. On the other hand, this catalyst was active for the NO2-CH4-O2 reaction, while the conversion of NO2 decreased with decreasing concentration of NO2. The catalytic activity of ln/H-ZSM-5 for the reduction of 1000 ppm NO was enhanced by the addition of Ir and R almost to the level of NO2 reduction on ln/H-ZSM-5, indicating that these precious metals worked as the catalytic sites for NO oxidation, which is a necessary step for NO reduction with CH4. With decreasing NO concentration to 100 ppm, however, the increase in NO conversion was observed on lr/ln/H-ZSM-5 and the conversion of NO exceeded that of NO2 on ln/H-ZSM-5. This can not simply be explained by the catalytic activity of Ir for NO oxidation. 

Kinetic parameters for NOx reduction are summarized in Table 1. It is obvious that the addition of Ir to ln/H-ZSM-5 led to the decrease in reaction orders with respect to NO, CH4, and O2 in the NO-CH4-O2 reaction. The decrease in the order for NO can explain that lr/ln/H-ZSM-5 was effective for the reduction of NO at low concentrations. On the contrary, the reaction orders with respect to NO2, CH4, and O2 in the NO2-CH4-O2 reaction were not significantly changed by the addition of Ir. The retarding effect of CH4... 

Table 1. Summary of kinetic data for NOX-CH4-O2 reaction on ln/H-ZSM-5 and lr/ln/H-ZSM-5 catalysts.

Figure 3.54 Measured gas exit temperatures for a catalytic H2/O2 reaction with varying H2 content in 0.5 sipm synthetic air (A) and oxygen (T) enriched air (0.1 sipm oxygen -r 0.2 sipm nitrogen) [115].

In aromatic combustion flames, cyclopentadienyl radicals (c-CgHj ) can be precursors for PAH formation. " At high temperatures, benzene is oxidized by reaction with an oxygen molecule to yield phenylperoxy (C6H5O2 ) radical, via the initial formation of the phenyl radical (by C-H bond cleavage) and then the rapid addition of O2 (reaction 6.16). After expulsion of CO from phenylperoxy radical, a resonance-stabilized cyclopentadienyl radical (c-CgHg ) is formed (reaction 6.16). 

Carbon monoxide adsorbed on sufficiently small palladium particles disproportionates to surface carbon and carbon dioxide. This does not occur on large particles. The CO-O2 reaction is shown to be structure-insensitive provided the metal surface available for the reaction is estimated correctly. 

Thus, although CO disproportionation is structure-sensitive, the CO-O2 reaction appears to be structure-insensitive at both 445 K and 518 K, provided we define correctly the number of Pd sites available for reaction at both temperatures. It should also be noted that the turnover rate at 445 K is the same on metal particles supported on 1012 a-A O, 0001 a-A O, and... 

SOD-inhibitable reduction of cytochrome c is thus now widely used to measure 02" production by activated neutrophils. It is an extremely-selective method, being specific for O2", and is easily measured spectrophotometrical-ly. Because SOD can convert two molecules of O2" into one molecule of H2O2 and one molecule of O2 (reaction 5.1), catalase (which degrades H2O2... 

Because the entropy change for the H2/O2 reaction is negative, the reversible potential of the H2/O2 fuel cell decreases with an increase in temperature by 0.84 mV/°C (assuming reaction product is liquid water). For the same reaction, the volume change is negative therefore, the reversible potential increases with an increase in pressure. 

The reactions of the species H3O+, NO+, and O2+ with a range of aldehydes and ketones have been studied by the selected ion flow tube (SIFT) method. H3O+ protonates ketones and aldehydes, with the latter eliminating water under the conditions of measurement. Similarly, NO+ associates with ketones, but this is followed by hydride transfer for the aldehydes. O2+ reactions typically produce several ionic products. 

Figure 10b. ONCs yield in C3FI6 +NO + O2 reaction over perovskites [19-21] Conditions GHSV=55,000 h, 3000 ppm CgHg, 3000 ppm NO, 1% Oj.

Figure 21. Effect of reaction time on NO conversion in CsHg + NO + O2 reaction over LaFco 8CU0.2O3 perovskite under various SO2 feed concentrations [86]. Conditions GHSV=50,000 h , 3000 ppm C3FL, 3000 ppm NO, 1% O2, 0-80 ppm SO2, 500 °C.

Figure 27a. Effect of O2 feed concentration on NO conversion in C3Hg + NO + O2 reactions over Lao ssAgo FeOs, Ag/AloOs and Mixture (I, II, III). Conditions 3000 ppm C3H0, 3000 ppm NO, 500 °C, 30,000 h [lOI],...

Figure 27b. Effect of O2 feed concentration on conversion in C3H< +NO + O2 reactions over...

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