Water vapor effect on the HNO<sub>3</sub> yield in the HO<sub>2</sub> + NO reaction: Experimental and theoretical evidence - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Physical Chemistry A Année : 2009

Water vapor effect on the HNO3 yield in the HO2 + NO reaction: Experimental and theoretical evidence

Résumé

The influence of water vapor on the production of nitric acid in the gas-phase HO2 + NO reaction was determined at 298 K and 200 Torr using a high-pressure turbulent flow reactor coupled with a chemical ionization mass spectrometer. The yield of HNO3 was found to increase linearly with the increase of water concentration reaching an enhancement factor of about 8 at [H2O] = 4 × 1017 molecules cm−3 (~50% relative humidity). A rate constant value k1bw = 6 × 10−13 cm3 molecule−1 s−1 was derived for the reaction involving the HO2*H2O complex: HO2*H2O + NO → HNO3 (1bw), assuming that the water enhancement is due to this reaction. k1bw is approximately 40 times higher than the rate constant of the reaction HO2 + NO → HNO3 (1b), at the same temperature and pressure. The experimental findings are corroborated by density functional theory (DFT) calculations performed on the H2O/HO2/NO system. The significance of this result for atmospheric chemistry and chemical amplifier instruments is briefly discussed. An appendix containing a detailed consideration of the possible contribution from the surface reactions in our previous studies of the title reaction and in the present one is included.
Fichier non déposé

Dates et versions

hal-00439172 , version 1 (06-12-2009)

Identifiants

Citer

Nadezhda Butkovskaya, Marie-Thérèse Rayez, Jean-Claude Rayez, Alexandre Kukui, Georges Le Bras. Water vapor effect on the HNO3 yield in the HO2 + NO reaction: Experimental and theoretical evidence. Journal of Physical Chemistry A, 2009, 113 (42), pp.11327-11342. ⟨10.1021/jp811428p⟩. ⟨hal-00439172⟩
146 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More