Temperature dependence of the rate constant for the HO2+BrO reaction

The rate constant for the HO2 + BrO reaction has been measured using the turbulent flow technique with high-pressure chemical ionization mass spectrometry for the detection of reactants and products. At room temperature and 100 Ton pressure, the rate constant (and the two standard deviation error limit) was determined to be (1.4 +/- 0.3) x 10(-11) cm(3) molecule(-1) s(-1). The temperature dependence of the rate constant was investigated between 298 and 210 K, and the data was fit to the following Arrhenius expression: (2.5 +/- 0.8) x 10(-12) exp[(520 +/- 80)/T] cm(3) molecule(-1) s(-1). Although the negative activation energy value agrees well with the current recommendation for stratospheric modeling, our absolute values for the rate constant are about a factor of 2 lower than this same recommendation.