Water as a catalyst in the reaction of nitrous acid (HONO) and Criegee intermediate (CH2OO)

Abstract

The present work employs the CCSD(T)/CBS//M06-2X/aug-cc-pVTZ level of theory to investigate the effect of a water monomer (WM) and dimer (WD) on the oxidation of nitrous acid (HONO) by the Criegee intermediate (CH₂OO). The present work suggests that similar to an uncatalyzed path, a water catalyzed reaction can also proceed via two paths, i.e., the oxygen atom transfer (OAT) and the hydrogen atom transfer (HAT) path. In addition, here also, the HAT path dominates over the OAT path. Besides, our study suggests that the rate of the water catalyzed reaction of the Criegee intermediate and HONO can be more than an order of magnitude higher than that of the corresponding uncatalyzed reaction.