Internal Structure of Incipient Soot from Acetylene Pyrolysis Obtained via Molecular Dynamics Simulations

Document Type

Article

Publication Date

7-4-2024

Publisher

American Chemical Society

Source Publication

Journal of Physical Chemistry A

Source ISSN

1089-5639

Original Item ID

DOI: 10.1021/acs.jpca.4c01548

Abstract

A series of reactive molecular dynamics simulations is used to study the internal structure of incipient soot particles obtained from acetylene pyrolysis. The simulations were performed using the ReaxFF potential at four different temperatures. The resulting soot particles are cataloged and analyzed to obtain statistics of their mass, volume, density, C/H ratio, number of cyclic structures, and other features. A total of 3324 incipient soot particles were analyzed in this study. Based on their structural characteristics, the incipient soot particles are classified into two classes, termed type 1 and type 2 incipient soot particles in this work. The radial distribution of density, cyclic (5-, 6-, or 7-member rings) structures, and C/H ratio inside the particles revealed a clear difference in the internal structure between type 1 and type 2 particles. These classes were further found to be well represented by the size of the particles, with smaller particles in type 1 and larger particles in type 2. The radial distributions of ring structures, density, and the C/H ratio indicated the presence of a dense core region in type 2 particles. In contrast, no clear evidence of the presence of a core was found in type 1 particles. In type 2 incipient soot particles, the boundary between the core and shell was found to be around 50–60% of the particle's radius of gyration.

Comments

Journal of Physical Chemistry, Vol. 128, No. 6 (July 4, 2024): 5175-5187. DOI.

Share

COinS