Effect of NH₃ and HCOOH on the H₂O₂ + HO → HO₂ + H₂O reaction in the troposphere: competition between the one-step and stepwise mechanisms.

ABSTRACT: The H₂O₂ + HO → HO₂ + H₂O reaction is an important reservoir for both radicals of HO and HO₂ catalyzing the destruction of O₃. Here, this reaction assisted by NH₃ and HCOOH catalysts was explored using the CCSD(T)-F12a/cc-pVDZ-F12//M06-2X/aug-cc-pVTZ method and canonical variational transition state theory with small curvature tunneling. Two possible sets of mechanisms, (i) one-step routes and (ii) stepwise processes, are possible. Our results show that in the presence of both NH₃ and HCOOH catalysts under relevant atmospheric temperature, mechanism (i) is favored both energetically and kinetically than the corresponding mechanism (ii). At 298 K, the relative rate for mechanism (i) in the presence of NH

SUBMITTER: Zhang T 

PROVIDER: S-EPMC9050117 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature