Autoxidation is the process by which organic compounds undergo oxidation due to molecular oxygen. This phenomenon is widespread in various reaction systems and plays a significant role in food and wine spoilage, ignition in internal combustion engines, and the formation of atmospheric secondary organic aerosols (SOA) from volatile emissions.

Therefore, autoxidation greatly affects both engine operation and efficiency, and, via the combustion pollutant and SOAs, climate, and air quality. In this thesis, the autoxidation chemistries of four typical hydrocarbon reactants including n-nonane, n-dodecane, n-heptane, and limonene are experimentally and numerically studied in the ideal reactors. They are either representative molecules found in fuels or ubiquitous in urban atmospheric environments.

In the second part, the low-T oxidation of a long-chain alkane representative of jet and diesel fuel (i.e., n-dodecane) was studied. Potential reaction channels of the observed intermediates were proposed and clarified. The low-T oxidation reaction scheme of n-dodecane was expanded by the proposed reactions. 

Low-T oxidation of n-heptane, a crucial surrogate component of gasoline fuel, has been extensively investigated. However, the chemical sensitization impact of NO on low-T oxidation chemistry is still limited. In the third part, the chemical effects of different amounts of NO on the low-T oxidation chemistry of n-heptane were thoroughly examined. A detailed kinetic model was developed and utilized to explain the observed experimental phenomenon. NO addition had a significant inhibitory effect on the formation of oxygenated intermediates during the low-T oxidation process.

Limonene is one of the most emitted biogenic compounds in the atmosphere. In the fourth portion of this thesis, the atmospheric autoxidation chemistry of limonene was studied using the flow tube reactor. Different temperatures and relative humidity levels were used to examine the formation of highly oxygenated organic molecules (HOM) and SOAs. The generation of HOMs and even SOAs could be promoted in low temperature and high relative humidity level conditions.

The work reported in this thesis provides valuable insights for the development of cleaner and more efficient combustion systems, as well as strategies to control pollutant emissions and improve air quality.