Hydroxyl radical plays an important role in atmospheric and combustion chemistry. Self reaction of hydroxyl radicals are of great importance in laboratory kinetic studies. OH    +          OH      -->     H2O     +     O                (1a)OH    +          OH      -->    H2O2                                            (1b) Channel 1b is pressure dependent, while channel 1a is considered to be pressure independent. In this study, we determined the rate constant of channel 1a by measuring the ozone yield in the photolysis of the reactive mixture N2O/H2O/O2/He at 193.3 nm. Oxygen atoms formed in channel 1a were converted to ozone in fast reaction 3: O         +          O2       -->       O3                                                           (3)  Transient absorption profiles of OH (308 nm) and O3 (253 nm) were recorded at the same experimental conditions. The ozone build-up profiles were fitted using a small reaction mechanism with explicit temporal profiles of OH. A preliminary value of the rate constant of reaction 1a at 298 K is: k1a = (1.4 � 0.2) x10-12 cm3molecule-1s-1

Study of kinetics of self-reaction of hydroxyl radicals

244th National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.