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Issue 9, 2020
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On the mechanism of soot nucleation

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The mechanism of carbon particulate (soot) inception has been a subject of numerous studies and debates. The article begins with a critical review of prior proposals, proceeds to the analysis of factors enabling the development of a meaningful nucleation flux, and then introduces new ideas that lead to the fulfillment of these requirements. In the new proposal, a rotationally-activated dimer is formed in the collision of an aromatic molecule and an aromatic radical; the two react during the lifetime of the dimer to form a stable, doubly-bonded bridge between them, with the reaction rooted in a five-member ring present on the molecule edge. Several such reactions were examined theoretically and the most promising one generated a measurable nucleation flux. The consistency of the proposed model with known aspects of soot particle nanostructure is discussed. The foundation of the new model is fundamentally the H-Abstraction-Carbon-Addition (HACA) mechanism with the reaction affinity enhanced by rotational excitation.

Graphical abstract: On the mechanism of soot nucleation

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09 Jan 2020
10 Feb 2020
First published
11 Feb 2020

Phys. Chem. Chem. Phys., 2020,22, 5314-5331
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On the mechanism of soot nucleation

M. Frenklach and A. M. Mebel, Phys. Chem. Chem. Phys., 2020, 22, 5314
DOI: 10.1039/D0CP00116C

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