Smog chamber study of H2O2 formation in etheneNOx and propeneNOx mixtures

Hydrogen peroxide formation in the photooxidation of CONOx, etheneNOx, and propeneNOx mixtures has been determined in the TVA 31 cubic meter smog chamber under the following conditions: [NOx] ca. 22–46 ppb; ethene = 0.22–1.1 ppm, [propene] = 0.12–0.97 ppm; [H2O] ca. 8 × 10−3 ppm. Ethene, propene, NO, NOx, PAN, HCHO, and CH3CHO were also monitored. Computer modeling was performed using the gas phase ethene and propene mechanism of the Regional Acid Deposition Model. There is good agreement between the model predicted and observed H2O2 concentrations. However, to successfully model all the propeneNOx experimental results, organic nitrate formation from the reaction of peroxy radicals with NO must be included in the mechanism.