Interaction of hydrogen atoms with carbon-sp2 structures: adsorption energetics and Eley-Rideal dynamics

The interaction and dynamics of hydrogen atoms on and with graphitic substrates is summarized in the light of their possible relevance for hydrogen formation in the interstellar medium. Firstly, accurate DFT results for adsorption of single hydrogen atoms, dimer and cluster formation and edge-related effects, are rationalized with the help of simple tight-binding ideas, in order to shed light about the general mechanisms governing such processes. Secondly, recent quantum scattering results for the Eley-Rideal formation reaction are shown in an astrophysically relevant cold collision energy regime