Kinetic study of the reactions of Cl atoms with HNO3, H2O2, and HO2

The kinetics of the reactions of Cl atoms with HNO3, H2O2, and HO2 have been studied by the discharge flow–mass spectrometric technique. The following rate constants were obtained (in cm3 molecule−1⋅s−1): Cl+HNO3→HCl+NO3, k=1.5 ×10−11 exp(−8700/RT) in the range 298–633 K; Cl+H2O2 →HCl+HO2, k= (4.0±0.4) ×10−13 at 298 K; Cl+HO2→HCl +O2, k= (6.8±2.5) ×10−11 at 298 K. The stratospheric implication of these data is discussed, and it is estimated that the Cl+HO2 reaction could have a comparable effect to the Cl+CH4 reaction as a sink of chlorine atoms in the stratosphere.