Reaction Kinetics of Criegee Intermediates with Nitric Acid.

This work investigated the reaction kinetics of HNO with four Criegee intermediates (CIs): CHOO, (CH)COO, methyl vinyl ketone oxide (MVKO), and methacrolein oxide (MACRO). Our results show that these reactions are extremely fast with rate coefficients of (1.51 ± 0.45) × 10, (3.54 ± 1.06) × 10, (3.93 ± 1.18) × 10, and (3.0 ± 1.0) × 10 cm s for reactions of HNO with CHOO, (CH)COO, -MVKO, and -MACRO, respectively. This is consistent with previous results for the reactions between CIs and carboxylic acids, but the rate coefficient of CHOO + HNO in the literature [Foreman 2016, 128, 10575] was found to be overestimated by a factor of 3.6. In addition, we did not observe any significant pressure dependence in the HNO reactions with CHOO and (CH)COO under 100-400 Torr. Our results indicate that in a dry area with severe NO pollution, the reactions of CIs with HNO and their products may be worthy of attention, but these reactions may be insignificant under high-humidity conditions. However, CI reactions with HNO may not play an important role in the atmospheric removal processes of HNO because of the low concentrations of CIs.