  Graphyne is a generic name for a carbon allotrope family of 2D structures,
where acetylenic groups connect benzenoid rings, with the coexistence of sp and
sp2 hybridized carbon atoms. In this work we have investigated, through fully
atomistic reactive molecular dynamics simulations, the dynamics and structural
changes of the hydrogenation of ALPHA, BETA, GAMMA graphyne forms. Our results
showed that the existence of different sites for hydrogen bonding, related to
single and triple bonds, makes the process of incorporating hydrogen atoms into
graphyne membranes much more complex than the graphene ones. Our results also
show that hydrogenation reactions are strongly site dependent and that the
sp-hybridized carbon atoms are the preferential sites to chemical attacks. In
our cases, the effectiveness of the hydrogenation (estimated from the number of
hydrogen atoms covalently bonded to carbon atoms) follows the ALPHA, BETA,
GAMMA graphyne structure ordering.
