FORMATION OF FORMIC-ACID AND ORGANIC PEROXIDES IN THE OZONOLYSIS OF ETHENE WITH ADDED WATER-VAPOR

Ozonolysis of C2H4 was carried out in a 580 l glass reaction vessel at 1 - 5 ppm reactant concentrations, with added water vapour. Under dry conditions ([H2O]0 = 0.5 ppm), HCHO, CO, CO2, (CHO)2O (formic acid an hydride), H2O2, and CH3OOH were identified as the reaction products. U nder wet conditions ([H2O]0 = 2 x 10(4) ppm), HCOOH yields approaching ca. 20 % of the converted C2H4, were observed, while no (CHO)2O was f ormed. Hydroxymethyl hydroperoxide, HOCH2OOH, was observed as the majo r peroxide, and found to be formed only in the presence of water vapou r. Direct reactions of H2O vapour with the excited CH2OO radicals and with stabilized CH2OO radicals are postulated to explain the formatio n of HCOOH and HOCH2OOH in the presence of water vapour, respectively.