Rate Coefficients for OH + NO (+N₂) in the Fall-off Regime and the Impact of Water Vapor.

ABSTRACT: The termolecular, association reaction between OH and NO is a source of nitrous acid (HONO), an important atmospheric trace gas. Rate coefficients for the title reaction as recommended by evaluation panels differ substantially at the temperatures and pressures that prevail in the Earth's boundary layer where the reaction is in the fall-off regime between low- and high-pressure limiting rate coefficients. Using pulsed laser methods for generation and detection of OH, we have reinvestigated the kinetics of the title reaction at pressures of 22-743 Torr (1 Torr = 1.333 hPa) and temperatures (273, 298, and 333 K) in pure N₂ and in N₂-H₂O bath gases. In situ optical absorption measurements were used to rule out any bias due to NO₂ or HONO impurities.

SUBMITTER: Sun W 

PROVIDER: S-EPMC9234955 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature