Theoretical Study on the Gas‐Phase Oxidation Mechanism of Ethylene by Nitrous Oxide

Abstract

The application of nitrous oxide (N 2 O) as a candidate oxidant provides a new opportunity for green propellants and propulsion systems. In this study, reaction paths are calculated by the DFT method in the B3LYP/6-31 + + G** approximation for direct oxidation of ethylene with nitrous oxide. The results indicate that the reaction between N 2 O and C 2 H 4 proceeds by a chain reaction mechanism. The reaction prefers the mechanism including 1,3-dipolar cyclo-addition of N 2 O to the double bond with the formation of unstable 4,5-dihydro-[1,2,3] oxadiazole intermediate via a transition state with an activation energy barrier of 102.54 kJ/mol, which is far below than that of N 2 O or C 2 H 4 decomposition. Subsequently, the next step is the decomposition of these intermediates through hydrogen transfer within the hydrocarbon backbone and the formation of the final products.

Combustion Chemistry of Unsaturated Hydrocarbons Mixed with NOx: A Review with a Focus on Their Interactions

“…Trenwith [64] [137] determined the accurate full-dimensional potential energy surface of the C 2 H 2 + N 2 O = oxadiazole reaction in the gas phase, which was fitted to about 64,000 high-level ab initio data using a machine learning approach. Li et al [138] calculated the reaction pathway of C 2 H 4 + N 2 O → products using DFT methods. The results indicated that the reaction preferred the mechanism that included the addition of N 2 O to the double bond of C 2 H 4 .…”