Dissociation of water on Ti-decorated fullerene clusters

Spin-polarized density functional theory calculations have been applied to investigate water dissociation catalyzed by Ti adsorbed on icosahedral C20, C60 and C80 fullerene clusters, in order to elucidate the roles that cluster size and Ti-cluster interaction play in the proposed hydrogen generation reaction. We find that two water molecules can be dissociated consecutively by overcoming moderate energy barriers of a few tenths of eV, accompanied by the generation of a H2 molecule for all three clusters. Depending on the cluster size, the fullerene clusters may participate directly in water splitting or indirectly through stereochemical control of the Ti adsorption sites. Our results suggest that fullerene clusters can serve as a flexible platform for rational design of nanostructured catalysts for hydrogen generation.