THE REACTION OF ACTIVE NITROGEN WITH MIXTURES OF ETHYLENE AND NITRIC OXIDE

1965 ◽  
Vol 43 (7) ◽  
pp. 1899-1904 ◽  
Author(s):  
E. Fersht ◽  
R. A. Back
Keyword(s):  
Nitric Oxide ◽  
Nitrogen Atom ◽  
Active Nitrogen ◽  
Atom Concentration ◽  
Condensed Discharge ◽  
Excited Molecules ◽  
True Measure ◽  
Concerted Reaction

The reaction of active nitrogen, produced in a condensed discharge at 1 mm pressure, with mixtures of ethylene and nitric oxide has been studied with mixtures ranging in composition from pure ethylene to pure nitric oxide. The sum of HCN + 14N16N produced from mixtures of C2H4 and 15NO remained constant and equal to the HCN produced from pure C2H4 for NO concentrations up to 50 mole %. As more NO was added, this sum rose towards the value of 14N15N produced from pure 15NO. These data appear to lend support to the HCN yield from ethylene as the true measure of nitrogen atom concentration. It is suggested that 15NO also undergoes a concerted reaction with excited 14N14N molecules, probably in the A3 Σu+ state, to produce 14N15N, and that these excited molecules can be quenched by collision with ethylene or methane without consuming nitrogen or forming HCN.

THE REACTION OF NITROGEN ATOMS WITH OXYGEN ATOMS IN THE ABSENCE OF OXYGEN MOLECULES

1961 ◽  
Vol 39 (8) ◽  
pp. 1601-1607 ◽  
Author(s):  
C. Mavroyannis ◽  
C. A. Winkler
Keyword(s):  
Nitric Oxide ◽  
Nitrogen Atom ◽  
Rate Constant ◽  
Rate Constants ◽  
Flow System ◽  
Titration Method ◽  
Active Nitrogen ◽  
Reaction Tube ◽  
Fast Flow ◽  
Oxygen Atoms

The reaction has been studied in a fast-flow system by introducing nitric oxide in the gas stream with excess active nitrogen. The nitrogen atom consumption was determined by titrating active nitrogen with nitric oxide at different positions along the reaction tube. The rate constant is found to be k1 = 1.83(± 0.2) × 1015 cc2 mole−2 sec−1 at pressures of 3, 3.5, and 4 mm, and with an unheated reaction tube.The homogeneous and surface decay of nitrogen atoms involved in the above system were studied using the nitric oxide titration method, and the rate constants were found to be k3 = 1.04 ± 0.17 × 1016 cc2 mole−2 sec−1, and k4 = 2.5 ± 0.2 sec−1 (γ = 7.5 ± 0.6 × 10–5), respectively, over the range of pressures from 0.5 to 4 mm with an unheated reaction tube.

Kinetics of the reactions of active nitrogen with oxygen and with nitric oxide

1961 ◽  
Vol 261 (1305) ◽  
pp. 259-273 ◽  
Keyword(s):  
Nitric Oxide ◽  
Nitrogen Atom ◽  
Mean Value ◽  
Molecular Constants ◽  
Active Nitrogen ◽  
Gaseous Products ◽  
A Value ◽  
Rate Of Decay ◽  
Products Of Reaction ◽  
Fast Flow

The rate of decay of nitrogen atoms in a fast-flow system in the presence of oxygen has been studied between 412 and 755°K. Nitrogen atom concentrations were estimated by titration with nitric oxide. The slow primary step can be represented by N + O 2 = NO + O, (1) while the much more rapid secondary reaction (2) removes the nitric oxide formed in reaction (1) N + NO = N 2 + O. (2) Reaction (1) was found to be first order in both nitrogen atom and oxygen molecule concentrations, and k 1 could be represented by the expression k 1 = 8.3 x 10 12 exp (— 7100/ RT ) cm 3 mole -1 s -1 between 412 and 755 °K. Under conditions of large oxygen flow rates and at high temperatures the air afterglow continuum was observed with low but easily measurable intensity in the gaseous products of reaction of oxygen with active nitrogen. Both nitric oxide and oxygen atoms are therefore present, and not all the nitric oxide formed in reaction (1) is consumed in reaction (2). These nitric oxide concentrations were determined by measuring the intensity of the air afterglow with a photomultiplier cell, which was calibrated by observation of the increase in the air afterglow intensity when known quantities of nitric oxide were added between the first mixing point and the photomultiplier. In this way a value of k 2 = 3.0 x 10 13 exp( — 200/ RT ) cm 3 mole -1 s -1 was determined. The mean value of k 2 between 476 and 755 °K was 2.5 x 10 13 cm 3 mole -1 s -1 , and was practically independent of temperature over this range, corresponding to a reaction occurring at about one sixth of the bimolecular collision frequency. It can be shown that both reactions (1) and (2) are expected to proceed through transition complexes having very similar molecular constants and vibration frequencies to those of nitrogen dioxide. However, the ratio of the frequency factors calculated on this basis, A 1 / A 2 = 1.4, was much larger than the experimentally determined value of 0.3, and this discrepancy is outside the limits of experimental error.

CATALYZED RECOMBINATION OF NITROGEN ATOMS, AND THE POSSIBLE PRESENCE OF A SECOND ACTIVE SPECIESIN ACTIVE NITROGEN

1960 ◽  
Vol 38 (12) ◽  
pp. 2514-2522 ◽  
Author(s):  
Roger Kelly ◽  
C. A. Winkler
Keyword(s):  
Rate Constant ◽  
Pressure Range ◽  
Order Rate Constant ◽  
Active Species ◽  
Third Order ◽  
Active Nitrogen ◽  
Atom Concentration ◽  
Order Rate ◽  
Excited Molecules ◽  
Atom Decay

The reactions of ethylene, ethane, and ammonia with active nitrogen have been studied over the pressure range 0.3 to 4 mm usinganunheatedreaction vessel. The object was to determine why each reactant shows, as is well-known, a smaller extent of reaction at lower temperatures than would be predicted from the atom concentration. It was concluded that ethylene probably brought about homogeneouscatalyzedrecombination, i.e. the process [Formula: see text] followed by N + N•C2H4 → N2 + C2H4. The over-all third-order rate constant appeared to be very large, about 1.8 × 10−28 cc2 molecule−2 sec−1. The behavior of ammonia was quite different from that of ethylene and it was, in fact, possible to show that the extent of reaction was not governed by the instantaneous atom concentration at all. The results can be explained qualitatively, however, if it is assumed that excited molecules formed in the course of homogeneous atom decay constitute a second active species in active nitrogen. This view serves also to explain the failure in such work as that of Kistiakowsky etal. to observe ammonia destruction or excited molecules when especially low atom concentrations are used. The few experiments involving ethane were sufficient to show that the reactivity was low for a different reason than with ethylene.

EXCITED MOLECULES AS THE REACTIVE SPECIES IN ACTIVE NITROGEN

1954 ◽  
Vol 32 (4) ◽  
pp. 399-403 ◽  
Author(s):  
R. A. Back ◽  
Margaret Menzies ◽  
C. A. Winkler
Keyword(s):  
Thermal Decomposition ◽  
Reactive Species ◽  
Active Nitrogen ◽  
Electronic Level ◽  
Decomposition Reactions ◽  
Condensed Discharge ◽  
Excited Molecules

No reaction has been detected between ethylene and nitrogen molecules obtained in the thermal decomposition of metallic azides. Since such decomposition reactions apparently produce nitrogen molecules excited to the same electronic level as those present in active nitrogen formed by a condensed discharge, it might be inferred that excited molecules are not the reactive species in active nitrogen.

Destruction des oxydes d'azote à pression atmosphérique

1984 ◽  
Vol 62 (4) ◽  
pp. 667-670 ◽  
Author(s):  
Odile Dessaux ◽  
Pierre Goudmand ◽  
Gérard Moreau ◽  
Brigitte Mutel
Keyword(s):  
Energy Consumption ◽  
Nitrogen Atom ◽  
Nitrogen Oxides ◽  
Atmospheric Pressure ◽  
Energy Cost ◽  
Microwave Discharge ◽  
Active Nitrogen ◽  
Atom Concentration ◽  
Theoretical Cost

Active nitrogen produced at atmospheric pressure by a microwave discharge is found to require less energy consumption for the decomposition of nitrogen oxides. Important parameters improving the energy cost are described: NOx must be introduced in a visually well-limited zone where the nitrogen atom concentration is maximum, the energy cost is then nearly equal to the theoretical cost.

THE REACTION OF ACTIVE NITROGEN WITH PROPYLENE

1952 ◽  
Vol 30 (12) ◽  
pp. 915-921 ◽  
Author(s):  
G. S. Trick ◽  
C. A. Winkler
Keyword(s):  
Double Bond ◽  
Nitrogen Atom ◽  
Hydrogen Cyanide ◽  
Atomic Hydrogen ◽  
Atomic Nitrogen ◽  
Active Nitrogen

The reaction of nitrogen atoms with propylene has been found to produce hydrogen cyanide and ethylene as the main products, together with smaller amounts of ethane and propane and traces of acetylene and of a C4 fraction. With excess propylene, the nitrogen atoms were completely consumed and for the reaction at 242 °C., 0.77 mole of ethylene was produced for each mole of excess propylene added. For reactions at lower temperatures, less ethylene was produced. The proposed mechanism involves formation of a complex between the nitrogen atom and the double bond of propylene, followed by decomposition to ethylene, hydrogen cyanide, and atomic hydrogen. The ethylene would then react with atomic nitrogen in a similar manner.

scholarly journals An updated model of the hot nitrogen atom kinetics and thermospheric nitric oxide

1997 ◽  
Vol 102 (A1) ◽  
pp. 285-294 ◽  
Author(s):  
J.-C. Gérard ◽  
D. V. Bisikalo ◽  
V. I. Shematovich ◽  
J. W. Duff
Keyword(s):  
Nitric Oxide ◽  
Nitrogen Atom

Comparative Production of Active Nitrogen from Nitrogen, Nitric Oxide and Ammonia, and from Nitrogen at Different Discharge Potentials

1956 ◽  
Vol 60 (8) ◽  
pp. 1100-1102 ◽  
Author(s):  
D. A. Armstrong ◽  
C. A. Winkler
Keyword(s):  
Nitric Oxide ◽  
Active Nitrogen

THE REACTIONS OF ACTIVE NITROGEN WITH THE BUTANES

1954 ◽  
Vol 32 (7) ◽  
pp. 718-724 ◽  
Author(s):  
R. A. Back ◽  
C. A. Winkler
Keyword(s):  
Nitrogen Atom ◽  
Rate Constants ◽  
Hydrogen Cyanide ◽  
Main Product ◽  
Activation Energies ◽  
Reactive Species ◽  
Atomic Nitrogen ◽  
Initial Attack ◽  
Active Nitrogen ◽  
Rate Controlling Step

The main product of the reactions of active nitrogen with n- and iso-butanes at 75 °C. and 250 °C. was hydrogen cyanide. Small amounts of C2 hydrocarbons, mainly ethylene and acetylene, were produced in both reactions. Second order rate constants were calculated on the assumption that the reactive species in active nitrogen is atomic nitrogen, and that the initial attack of a nitrogen atom is the rate-controlling step. The activation energies were then estimated to be 3.6 kcal. and 3.1 kcal. and the probability factors 4.5 × 10−4 and 4.4 × 10−4, for the n-butane and isobutane reactions respectively.

THE REACTIVE SPECIES IN ACTIVE NITROGEN

1962 ◽  
Vol 40 (6) ◽  
pp. 1082-1097 ◽  
Author(s):  
A. N. Wright ◽  
R. L. Nelson ◽  
C. A. Winkler
Keyword(s):  
Molecular Nitrogen ◽  
Reaction Vessel ◽  
Active Nitrogen ◽  
Atom Concentration ◽  
Vibrational Levels ◽  
Long Lifetime ◽  
Excited Nitrogen ◽  
A Minor ◽  
Hydrocarbon Reactions ◽  
Decomposition Of No

A study has been made of the discrepancy between the N-atom content of active nitrogen as inferred from the maximum HCN production from the reaction of many hydrocarbons, and that indicated by the extent of NO destruction. The HCN production from several hydrocarbons was similar at high reaction temperatures in a spherical reaction vessel, and was independent of reaction temperature in a cylindrical reaction vessel. The ratio (NO destroyed)/(HCN produced) was found to be independent of the mode of excitation òf the molecular nitrogen and of the N-atom concentration, and to be unaffected by the addition, upstream, of N2O or CO2. Although NH3 was found to be a minor product of the hydrocarbon reactions, HCN accounted for at least 96% of the N-atom content of the products under conditions where its formation is considered a measure of the N-atom concentration. The NO "titration" value, the maximum extent of HCN production from C2H4, and the destruction of NH3 after different times of decay of active nitrogen gave evidence that part of the NO reaction occurred, as does the NH3 reaction, with excited nitrogen molecules. The long lifetime of the N2* species capable of reaction with NO or NH3, as calculated from the above data, strongly favors its identification as low vibrational levels of the N2(A3∑u+) molecule. A consideration of the values for the NO/HCN, NH3/HCN, and NH3/NO ratios, after different times of decay, for poisoned and unpoisoned systems, suggested that the N2* responsible for the NH3 reaction is formed only during homogeneous recombination of N atoms, while the N2* responsible for reaction with NO might be produced by wall recombination as well. Possible reactions of excited molecules present in the active nitrogen – NO system that might lead to decomposition of NO without consumption of N atoms are discussed.

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