1. The HO4H → O3 + H2O reaction catalysed by acidic, neutral and basic catalysts in the troposphere.
- Author
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Zhang, Tianlei, Bi, Xiujuan, Wen, Mingjie, Liu, Shuai, Chai, Guang, Zeng, Zhaopeng, Wang, Rui, Wang, Wenliang, and Long, Bo
- Subjects
ABSTRACTION reactions ,TRANSITION state theory (Chemistry) ,GAS phase reactions ,HOLMIUM ,TROPOSPHERE ,CATALYSTS ,MOLECULAR physics - Abstract
A detailed effects of catalyst X (X = H
2 O, (H2 O)2 , NH3 , NH3 ···H2 O, H2 O···NH3 , HCOOH and H2 SO4 ) on the HO4 H → O3 + H2 O reaction have been investigated by using quantum chemical calculations and canonical vibrational transition state theory with small curvature tunnelling. The calculated results show that (H2 O)2 -catalysed reactions much faster than H2 O-catalysed one because of the former bimolecular rate constant larger by 2.6–25.9 times than that of the latter one. In addition, the basic H2 O···NH3 catalyst was found to be a better than the neutral catalyst of (H2 O)2 . However it is marginally less efficient than the acidic catalysts of HCOOH, and H2 SO4 . The effective rate constant (k't ) in the presence of catalyst X have been assessed. It was found from k't that H2 O (at 100% RH) completely dominates over all other catalysts within the temperature range of 280–320 K at 0 km altitude. However, compared with the rate constant of HO4 H → H2 O + O3 reaction, the keff values for H2 O catalysed reaction are smaller by 1–2 orders of magnitude, indicating that the catalytic effect of H2 O makes a negligible contribution to the gas phase reaction of HO4 H → O3 + H2 O. Highlights A detailed effects of catalyst of H2 O, (H2 O)2 , NH3 , NH3 ···H2 O, H2 O···NH3 , HCOOH and H2 SO4 on the HO4 H → O3 + H2 O reaction has been performed. From energetic viewpoint, H2 SO4 exerts the strongest catalytic role in HO4 H → O3 + H2 O reaction as compared with the other catalysts. At 0 km altitude H2 O (at 100% RH) completely dominates over all other catalysts within the temperature range of 280–320 K. HO4 H → H2 O + O3 reaction with H2 O cannot be compete with the reaction without catalyst, due to the fact that the effective rate constants in the presence of H2 O are smaller. [ABSTRACT FROM AUTHOR]- Published
- 2020
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