Atomic Force Microscopy Identifying Fuel Pyrolysis Products and Directing the Synthesis of Analytical Standards

Area of Science:

• Analytical Chemistry
• Organic Chemistry
• Materials Science

Background:

• Polycyclic Aromatic Hydrocarbons (PAH) are prevalent in fuel combustion and pyrolysis.
• Characterizing complex PAH mixtures in fuels remains a significant analytical challenge.
• Novel PAH structures may have implications for fuel properties and environmental impact.

Purpose of the Study:

• To develop and demonstrate a multidisciplinary methodology for detecting, identifying, and quantifying novel PAH in complex molecular mixtures.
• To characterize the supercritical pyrolysis products of n-decane, a model fuel, using the developed method.
• To establish a route for the synthesis and validation of newly discovered PAH as analytical standards.

Main Methods:

• Integration of Atomic Force Microscopy (AFM) with High-Performance Liquid Chromatography (HPLC), Diode-Array UV-Vis Absorbance, and Mass Spectrometry (MS).
• Application of synthetic chemistry for the preparation of novel compounds identified by AFM.
• Characterization of supercritical pyrolysis products derived from n-decane.

Main Results:

• Discovery and identification of a novel PAH, benz[l]indeno[1,2,3-cd]pyrene, in n-decane pyrolysis products.
• Successful chemical synthesis and AFM verification of the novel benz[l]indeno[1,2,3-cd]pyrene.
• Unequivocal identification and quantification of this novel PAH as a fuel product using the synthesized reference standard.
• Detection of several previously unidentified five- to eight-ring PAH, representing new fuel pyrolysis/combustion products.

Conclusions:

• The integrated AFM, analytical chemistry, and synthetic chemistry approach enables the discovery of novel PAH in complex mixtures.
• This methodology provides a pathway for creating new analytical standards for previously uncharacterized fuel components.
• The findings advance the understanding of PAH formation during fuel pyrolysis and combustion.