title: Etching of graphene in a Hydrogen-rich Atmosphere towards the Formation of Hydrocarbons in Circumstellar Clouds.
abstract: We describe a mechanism that explains the formation of hydrocarbons and hydrocarbyls from hydrogenated graphene/graphite; hard C-C bonds are weakened and broken by the synergistic effect of chemisorbed hydrogen and high temperature vibrations. Total energies, optimized structures, and transition states are obtained from Density Functional Theory simulations. These values have been used to determine the Boltzman probability for a thermal fluctuation to overcome the kinetic barriers, yielding the time scale for an event to occur. This mechanism can be used to rationalize the possible routes for the creation of small hydrocarbons and hydrocarbyls from etched graphene/graphite in stellar regions.
authors.affiliation: Dept. Surfaces, Coatings & Molecular Astrophysics, Institute of Materials Science of Madrid (ICMM-CSIC), ES-28049 Madrid (Spain).
authors.forename: José I
authors.initials: JI
authors.lastname: Martínez
authors.affiliation: Dept. Surfaces, Coatings & Molecular Astrophysics, Institute of Materials Science of Madrid (ICMM-CSIC), ES-28049 Madrid (Spain).
authors.forename: José A
authors.initials: JA
authors.lastname: Martín-Gago
authors.affiliation: Dept. Surfaces, Coatings & Molecular Astrophysics, Institute of Materials Science of Madrid (ICMM-CSIC), ES-28049 Madrid (Spain).
authors.forename: José
authors.initials: J
authors.lastname: Cernicharo
authors.affiliation: Dept. Surfaces, Coatings & Molecular Astrophysics, Institute of Materials Science of Madrid (ICMM-CSIC), ES-28049 Madrid (Spain).
authors.forename: Pedro L
authors.initials: PL
authors.lastname: de Andres