Revealing Mechanistic Insights into Amorphous Graphite Formation from Oxygenated Polar Heavy-End Aromatic Feedstock

Carbon fibers exhibit a wide range of structures including crystalline, amorphous, and partially crystalline arrangements. Research on disordered carbon has recently unveiled intriguing carbon phases, particularly amorphous graphite, which possesses unique mechanical, thermal, and electronic properties due to its inherent topological defects. In this study, we employed ReaxFF-MD simulations to investigate the carbonization reactions and high-temperature graphitization process of an oxygenated polar aromatic precursor, anthrone. These simulations effectively captured the molecular processes involved in high-temperature reaction mechanisms, providing valuable insights into the underlying chemistry, reaction pathways of volatile molecules, and structural properties of the final product. We monitored the removal rate and percentage of noncarbon-containing volatile gases as indicators of the transition from carbonization to graphitization processes and studied the evolution of all carbon ring structures. Interestingly, we found that the final graphitic phase exhibited clusters of noncontinuous graphitic layers consisting of pentagons, heptagons, and hexagons. The structure can be classified as amorphous graphite. Puckering was observed near the pentagon-heptagon-hexagon network, resulting in corrugation between the layers. The novelty of this work lies in developing insights into the mechanistic details of the formation of amorphous graphite from a polar aromatic feedstock. These findings contribute to a better understanding of the carbonization and graphitization processes and can guide the optimization of synthesis techniques for amorphous graphite materials with tailored properties.

Automated summary

This study investigates the carbonization and high-temperature graphitization process of an oxygenated aromatic precursor using molecular dynamics simulations. The formation mechanism and structural properties of amorphous graphite are revealed. These findings contribute to a better understanding of carbonization and graphitization processes and guide the optimization of synthesis techniques for amorphous graphite materials.