Insight into the Kinetics of Isomerization and β-Scission Reactions Following H-Abstraction in 2-Pentanone Combustion

2-Pentanone is a significant carbon-neutral fuel. To better understand 2-pentanone combustion, the CCSD(T)/CBS method was used to calculate the potential energy surfaces (PES) for H-abstraction, isomerization, and β-scission reactions of 2-pentanone. Rate constants for the above reactions were calculated by the MESS employing conventional transition state theory (CTST) at 300–2000 K. The findings reveal adherence to the Evans–Polanyi principle in the H-abstraction reactions of 2-pentanone by H atoms. Specifically, the 2-site shows more competitive kinetics due to having the lowest energy barrier of 7.8 kcal/mol. The 4-position has the highest energy barrier, making the reaction difficult to occur. In the subsequent reactions, the breaking of C–H bonds is most competitive at low temperatures. In particular, the H transfer from INT1 to INT3 has a potential well height of 24.8 kcal/mol. The β-scission reactions become the main pathway for the depletion of pentanone radicals with increasing temperature. This study significantly extends the kinetic parameters of 2-pentanone combustion over a wide range of temperatures and pressures, which is expected to contribute to the development of 2-pentanone combustion models.