$55,000; American Chemical Society (ACS) Petroleum Research Fund (PRF) Undergraduate New Investigators (UNI) Grants

Identification and structure determination of reactive intermediates in the reactions of NOx and resonance-stabilized hydrocarbon radicals
Principal Investigator: Timothy Barnum, assistant professor of chemistry

Ongoing development of clean, efficient internal combustion engines remains critical to maximizing the use of limited fossil fuel resources. The production of undesirable chemical species, including nitrogen oxides (NOx) and soot particles, hinders the efficient use of fuels derived from petroleum and contributes to objectionable emissions. Soot forms via reactions of resonance-stabilized hydrocarbon radicals (RSRs), generated from the high-temperature decomposition of gasoline or diesel fuel. There is currently limited understanding of how incipient soot chemistry is impacted by reactions of RSRs with NOx.

PI Barnum aims to generate mechanistic insights into the reactions of RSRs and NOx through the identification and structural characterization of important reactive intermediates in the reactions of propargyl and allyl radical with nitric oxide (NO), which are the simplest examples of RSR + NOx reactions. Through a multi-step experimental approach, the PI will determine the elementary chemical steps in the simplest RSR and NOx reactions, providing insight into the complex reaction networks in fossil fuel combustion. The experimental data will be interpreted alongside computational investigations in order to reveal the fundamental chemical mechanisms.

Through this project, PI Barnum will engage undergraduates majoring in physics, chemistry, and engineering. These students will learn a range of skills including design and construction principles of scientific instrumentation, experience in vacuum technology and microwave electronics, and the critical thinking skills required to engage with the scientific literature.