  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.
