O + C2H2 -> H + HCCO
k = 1.35E+07 T^2 exp(-1900 cal/mol /RT) cm3/mol s
- SOURCE:
- Michael, J.V., and Wagner, A.F. (1990) J. Phys. Chem. 94,
2453.
- Peeters, J., Schaekers, M., and Vinckier, C. (1986) J. Phys. Chem.
90, 6552.
- Frank, P., Bhaskaran, K.A., and Just, Th. (1986) 21st Symposium
(International) on Combustion, p. 885.
- COMMENTS:
- The overall rate coefficient for O + C2H2 -> Products,
21.
O + C2H2 -> H + HCCO
22.
O + C2H2 -> OH + C2H
23.
O + C2H2 -> CO + CH2,
- is from Michael and Wagner (1990).
- The branching fraction for the H atom channel k(21) is uncertain. Laser
photolysis (Huang et al 1994) and molecular beam (Schmoltner et al 1989)
experiments suggest values near 40%. However, many kinetics experiments
(Peeters et al 1986, Frank et al 1986, Michael and Wagner 1990, Boullart
and Peeters 1992, Peeters et al 1994) give H atom yields of up to 85%.
The branching ratio k21/(k21+k23) = 0.66 is from Peeters et al.(1986) and
Frank et al. (1986), and is also the same as an average of 7 studies.
- This channel served as an optimization variable for GRI-Mech 3.0 and
was not changed. In some target and validation calculations, the
k21/k23 branching ratio was erroneously reversed. Correct computations
for experiments sensitive to these steps showed no significant difference.
- REFERENCES:
- Michael, J.V., and Wagner, A.F. (1990) J. Phys. Chem. 94,
2453.
- Peeters, J., Schaekers, M., and Vinckier, C. (1986) J. Phys. Chem.
90, 6552.
- Frank, P., Bhaskaran, K.A., and Just, Th. (1986) 21st Symposium
(International) on Combustion, p. 885.
- Peeters, J., Boullart, W., and Langhans, I. (1994) Int. J. Chem.
Kinet. 26, 869.
- Boullart, W., and Peeters, J. (1992) J. Phys. Chem. 96,
9810.
- Schmoltner, A. M., Chu, P. M., and Lee, Y. T. (1989) J. Chem. Phys.
91, 5365.
- Huang, X., Xing, G., and Bersohn, R. (1994) J. Chem. Phys.
101,
5818.
______________________________________________________________________
Temp delta-S delta-H kf kr Keq
(K) (cal/mol K) (kcal/mol) ----(mol,cm3,s)-----
______________________________________________________________________
300 -.1 -19.6 5.02E+10 2.88E-04 1.75E+14
500 .2 -19.4 5.00E+11 1.40E+03 3.57E+08
1000 .7 -19.1 5.19E+12 2.43E+08 2.14E+04
1500 .7 -19.1 1.60E+13 1.84E+10 8.71E+02
2000 .6 -19.3 3.35E+13 1.92E+11 1.74E+02
2500 .4 -19.8 5.76E+13 8.83E+11 6.52E+01
3000 .2 -20.4 8.83E+13 2.65E+12 3.33E+01
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