Absence of spillover of hydrogen adsorbed on small palladium clusters anchored to graphene vacancies

Experimental evidence exists for the enhancement of hydrogen storage capacity porous carbons when these materials are doped with metal nanoparticles. One most studied dopants is palladium. Dissociation molecules and spillover H atoms towards carbon substrate has been advocated as reason capacity. We have investigated this mechanism by performing ab initio density functional molecular dynamics (AIMD) simulations deposition on Pd6 clusters anchored graphene vacancies. The initially near-saturated atomic hydrogen. This condition would facilitate occurrence spillover, since our energy calculations based theory indicate that migration preadsorbed becomes exothermic Pd high coverages. However, AIMD show prefer to intercalate absorb within cluster rather than migrate substrate. These results reveal activation barriers exist preventing from