Rate Constants for H + O2 + M from 298 to 639 K for M = He, N2 and H2O

Article abstract of DOI:10.1021/j100340a003

The reaction H + O2 + M -> HO2 + M (M = He, N2, and H2O) has been studied from 298 to 639 K in the third-order regime by use of a high-pressure discharge flow apparatus.Relative rate constants, k_M/K_He, derived from these measurements show definite temperature dependences, highlighting the change in relative bath gas efficiences with temperature.The rate data are well-represented in Arrhenius form, with k(He) = (4.0 +/- 1.2) x 1E-33 exp<(560 +/- 100)/T>, k(N2) = (6.5 +/- 2.2) x 1E-33 exp<(680 +/- 110)/T>, and k(H2O) = (1.9 +/- 0.9) x 1E-32 exp<(1050 +/- 140)/T>.Use of total collision rates as the reference collision rate is seen to account for the large M effect observed for H2O as a third body.