Journal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volume 113, Issue 30, Pages 8374-8379Publisher
NATL ACAD SCIENCES
DOI: 10.1073/pnas.1604772113
Keywords
furans; oxygenated hydrocarbons; soot; organic carbon; black carbon
Categories
Funding
- US Department of Energy (DOE) Office of Basic Energy Sciences (BES), Single Investigator Small Group Research Grant [DE-SC0002619]
- Alexander von Humboldt Foundation Feodor Lynen Fellowship
- DOE BES, the Division of Chemical Sciences, Geosciences, and Biosciences
- DOE's National Nuclear Security Administration [DE-AC04-94-AL85000]
- DOE BES [DE-AC02-05CH11231]
- U.S. Department of Energy (DOE) [DE-SC0002619] Funding Source: U.S. Department of Energy (DOE)
Ask authors/readers for more resources
Many oxygenated hydrocarbon species formed during combustion, such as furans, are highly toxic and detrimental to human health and the environment. These species may also increase the hygroscopicity of soot and strongly influence the effects of soot on regional and global climate. However, large furans and associated oxygenated species have not previously been observed in flames, and their formation mechanism and interplay with polycyclic aromatic hydrocarbons (PAHs) are poorly understood. We report on a synergistic computational and experimental effort that elucidates the formation of oxygen-embedded compounds, such as furans and other oxygenated hydrocarbons, during the combustion of hydrocarbon fuels. We used ab initio and probabilistic computational techniques to identify low-barrier reaction mechanisms for the formation of large furans and other oxygenated hydrocarbons. We used vacuum-UV photoionization aerosol mass spectrometry and X-ray photoelectron spectroscopy to confirm these predictions. We show that furans are produced in the high-temperature regions of hydrocarbon flames, where they remarkably survive and become the main functional group of oxygenates that incorporate into incipient soot. In controlled flame studies, we discovered similar to 100 oxygenated species previously unaccounted for. We found that large alcohols and enols act as precursors to furans, leading to incorporation of oxygen into the carbon skeletons of PAHs. Our results depart dramatically from the crude chemistry of carbon-and oxygen-containing molecules previously considered in hydrocarbon formation and oxidation models and spearhead the emerging understanding of the oxidation chemistry that is critical, for example, to control emissions of toxic and carcinogenic combustion by-products, which also greatly affect global warming.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available