Theoretical study on the reaction of ketene + HO₂: From electronic structure to model applications

Reaction kinetics study of ketene + hydroperoxyl radical (HO₂) and its applications into model prediction for ketene oxidation have been investigated in this work. Potential energy surfaces (PESs) for key reactions have been obtained by employing ROCCSD(T)/CBS//BH&HLYP/6–311++G(d,p) methods. The RRKM/Master Equation was solved to calculate the temperature and pressure dependent rate constants for the title reaction pathways. Temperature-dependent thermochemistry data for ketene + HO₂ radical system has also been studied. The bimolecular pathways forming HCHO + CO + OH, oxiranone + OH and acetyl radical + oxygen were found to be dominant at high temperatures. Rate constants and thermodynamics data have been incorporated into the ketene mechanism from Konnov's group (A.S. Savchenkova et al., Combust. Flame, 218 (2020) 28-41) to investigate their influence on the performance of ketene oxidation. Sensitivity and flux analysis were also carried out at 850 K to investigate the kinetics behavior of ketene + HO₂ reaction system at intermediate temperatures. This work provides a better understanding of ketene oxidation and reactions between oxygenated hydrocarbons and hydroperoxyl radical.