Studies on the Reactions of CH (v = 0 and 1) with NO and O2

Abstract

Rate constants for the reactions of CH(X2Π : v = 0,1) with NO and O2 are measured under pseudo-first-order conditions at 297 ± 5 K. CH(X2Π : v = 0,1) radicals are generated by excimer laser photolysis of CHBr3 and (CH3)2 CO at 193 nm, and detected by the laser-induced fluorescence (LIF) technique. The overall rate constants obtained at the total pressure of 20 Torr Ar are: kNO(v = 0) = (1.6 ± 0.2) × 10−10, kNO(v = 1) = (1.3 ± 0.6) × 10−10, kO2(v = 0) = (3.5 ± 0.3) × 10−11, and kO2(v = 1) = (3.4 ± 0.8) × 10−11 (cm3 molecule−1 s−1). No apparent pressure dependence is indicated for the rate constants over the pressure range of 5—50 Torr Ar for CH + NO, and 5—30 Torr Ar for CH + O2 reactions, respectively. The reaction mechanisms are discussed based on the quantum mechanical calculations of the potential energy surfaces of CH + NO and CH + O2 systems.

Measurement of the rate coefficient of the reaction CH+O2 ? products in the temperature range 2200 to 2600 K

“…Okada et al [16] Since the CH concentration in our ex-OH ϩ CO. periments is very small compared to other species (less than 1% of the initial fuel concentration), the CH profiles are not sensitive to the products of reaction (125).…”

“…For the rate coefficient of reaction (182), the resulting temperature dependence in the range of can be described by following Arrhe-2200 -2600 K nius expression: 16 3…”

Combustion Chemistry of Nitrogen

“…Experimental data on this reaction are shown in Figure 2.57. Several groups have measured the rate at room temperature (Butler et al 1981;Wagal et al 1982;Lichtin et al 1984;Okada et al 1993), while two groups have measured the rate over extended ranges of low temperatures (Berman et al 1982;Becker et al 1993). There is only one direct high-temperature measurement .…”

Kinetics of CH radicals with O2: Evidence for CO chemiluminescence in the gas phase reaction

“…[5][6][7][8][9][10][11][12][13][14][15][16][17][18] No pressure dependence of the rate coefficient has been found in this range, and for (700 K < T > 300 K), the rate coefficient has a constant value, as it does in the 2200-3500 K range, though here it is a factor of 3-4 higherll-12 than the room temperature value. The room temperature value lies in the range (2.3-5.9) x 10-11 C m3 molec-1 s~l amid the various reported works, except that of Duncanson and Guillory9 who reported a much smaller value of 2.1 x 10-12 C m3 molec-1 s -l.…”