Calculations of adsorption, coadsorption, diffusion, and reaction barriers of H atoms in the H2 formation on a positively charged coronene

Abstract

DFT-D calculations of adsorption, diffusion and reaction barriers of atomic hydrogen radicals (H) to form H2 on positively charged coronene (Cor+) were studied for cis dimers (ortho, meta, and para) of H on central and edge rings. Results show, by comparison with the neutral system, that cationic polycyclic aromatic hydrocarbons (PAH) are more efficient for hydrogen recombination because these systems have a lower diffusion and reaction barriers. In some cases, hydrogen recombination does not take place because H desorption occurs. However, the adsorption of a third H leads to lower reaction barriers than in the dimer systems.