Graphite, and particularly defective graphite, is chosen to model soot particles. Quantum mechanical calculations are first carried out on molecular polycyclic-aromatic-hydrocarbon-type systems and then extended to a periodic representation of one graphite layer. The features of the interaction of H, HO, NO, NO2, and NO3 with these model systems are examined, with the aim of defining a suitable representation of the atmospheric or combustion gas-solid interactions by which functionalization reactions can take place. The more interesting interactions with small reactive molecules regard the edge of the graphene sheet and the in-plane carbon vacancies. While these interactions can be well described by sufficiently extended molecular models, periodic models are necessary to describe accurately the equilibrium geometries because they introduce the necessary geometric constraints. The ability of a graphene sheet to easily accommodate unpaired electrons in s or p orbitals is the basis for its interesting interactions with the small molecules present in tropospheric chemistry or combustion processes.

Modeling soot and its functionalization under atmospheric or combustion conditions by Density Functional Theory within molecular (polycyclic-aromatic-hydrocarbon-like) and periodic methodologies

GHIGO, Giovanni;MARANZANA, Andrea;TONACHINI, Glauco;
2004-01-01

Abstract

Graphite, and particularly defective graphite, is chosen to model soot particles. Quantum mechanical calculations are first carried out on molecular polycyclic-aromatic-hydrocarbon-type systems and then extended to a periodic representation of one graphite layer. The features of the interaction of H, HO, NO, NO2, and NO3 with these model systems are examined, with the aim of defining a suitable representation of the atmospheric or combustion gas-solid interactions by which functionalization reactions can take place. The more interesting interactions with small reactive molecules regard the edge of the graphene sheet and the in-plane carbon vacancies. While these interactions can be well described by sufficiently extended molecular models, periodic models are necessary to describe accurately the equilibrium geometries because they introduce the necessary geometric constraints. The ability of a graphene sheet to easily accommodate unpaired electrons in s or p orbitals is the basis for its interesting interactions with the small molecules present in tropospheric chemistry or combustion processes.
2004
108
3215
3223
GHIGO G; MARANZANA A; TONACHINI G; ZICOVICH-WILSON M; CAUSÀ M
File in questo prodotto:
File Dimensione Formato  
JPC-B.2004.108.3215.pdf

Accesso riservato

Tipo di file: PDF EDITORIALE
Dimensione 311.48 kB
Formato Adobe PDF
311.48 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/5790
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact