Effects of Pressure on Product Yields in the NOx Photooxidations of Selected Aromatic Hydrocarbons

Article abstract of DOI:10.1021/j100232a029

The yields of benzaldehyde and o-cresol from the photooxidation of toluene, and the yields of biacetyl from the photooxidation of o-xylene, have been determined over the pressure range ca. 60-740 torr at ca. 303 K by using the photolysis of CH3ONO-NO-air (or O2) mixtures to generate OH radicals.In addition, the benzaldehyde and o-cresol yields from toluene were determined at 323 K and 740-torr total pressure.The benzaldehyde and o-cresol yields at ca. 303 K were observed to be independent of pressure (62-740 torr) within the experimental errors, with mean values of 0.073 +/- 0.022 and 0.131 +/- 0.072, respectively.The data also do not indicate any significant effect of temperature on these yields between 303 and 323 K at 740-torr total pressure.The biacetyl yield from the o-xylene system at 301 +/- 2 K, however, was observed to decrease from 0.137 +/- 0.016 at 740 torr to 0.102 +/- 0.004 at 67-torr total pressure.These results are compared with previous literature data and their implications for chemical kinetic computer modeling of the NO_x photooxidations of toluene and o-xylene are discussed.