Direct measurements of the high temperature rate constants of the reactions NCN + O, NCN + NCN, and NCN + M.
Direct measurements of the high temperature rate constants of the reactions NCN + O, NCN + NCN, and NCN + M.
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直接测量 NCN O、NCN NCN 和 NCN M 反应的高温速率常数
DOI:
10.1039/c1cp22123j
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发表时间:
2012
期刊:
影响因子:
--
通讯作者:
G. Friedrichs
中科院分区:
文献类型:
--
作者:
J. Dammeier;N. Faßheber;G. Friedrichs
The rate constant of the reaction NCN + O has been directly measured for the first time. According to the revised Fenimore mechanism, which is initiated by the NCN forming reaction CH + N2 → NCN + H, this reaction plays a key role for prompt NOx formation in flames. NCN radicals and O atoms have been quantitatively generated by the pyrolysis of NCN3 and N2O, respectively. NCN concentration–time profiles have been monitored behind shock waves using narrow-bandwidth laser absorption at a wavelength of λ = 329.1302 nm. Whereas no pressure dependence was discernible at pressures between 709 mbar < p < 1861 mbar, a barely significant temperature dependence corresponding to an activation energy of 5.8 ± 6.0 kJ mol−1 was found. Overall, at temperatures of 1826 K < T < 2783 K, the rate constant can be expressed as kNCN + O = 9.6 × 1013 × exp(−5.8 kJ mol−1/RT) cm3 mol−1 s−1 (±40%). As a requirement for accurate high temperature rate constant measurements, a consistent NCN background mechanism has been derived from pyrolysis experiments of pure NCN3/Ar gas mixtures, beforehand. Presumably, the bimolecular secondary reaction NCN + NCN yields CN radicals hence triggering a chain reaction cycle that efficiently removes NCN. A temperature independent value of kNCN + NCN = (3.7 ± 1.5) × 1012 cm3 mol−1 s−1 has been determined from measurements at pressures ranging from 143 mbar to 1884 mbar and temperatures ranging from 966 K to 1900 K. At higher temperatures, the unimolecular decomposition of NCN, NCN + M → C + N2 + M, prevails. Measurements at temperatures of 2012 K < T < 3248 K and at total pressures of 703 mbar < p < 2204 mbar reveal a unimolecular decomposition close to its low pressure limit. The corresponding rate constants can be expressed as kNCN + M = 8.9 × 1014 × exp(−260 kJ mol−1/RT) cm3 mol−1 s−1(±20%).
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影响因子:
4.4
作者:
Rjh Robert Klein;A. Konnov;N. Dam;Ter Meulen
通讯作者:
Ter Meulen
DOI:
10.1524/zpch.1966.51.1_2.104
发表时间:
1966
期刊:
Zeitschrift für Physikalische Chemie
影响因子:
--
作者:
A. Martinengo;J. Troe;H. Wagner
通讯作者:
H. Wagner
影响因子:
1.5
作者:
M. Louge;R. Hanson
通讯作者:
R. Hanson
影响因子:
2.9
作者:
L. Moskaleva;M. Lin
通讯作者:
M. Lin
影响因子:
4.4
作者:
A. Dean;D. Steiner
通讯作者:
D. Steiner