The dissociation of H2 at close-packed Cu surfaces containing defects was studied by means of density-functional theory calculations. Reaction at vacancy and kink sites was highly favored over reaction at flat Cu terraces or at adatom or step sites. The energy barriers were made of a sum of the interaction between the H2 molecular states and the Cu(4sp) and Cu(3d) valence states. It was found to be the Cu(4sp) term which was responsible for the preference for the vacancy and kink sites, and the broken Cu-Cu bridge bonds at these sites were the cause of the high reactivity.

H2 Dissociation at Defected Cu - Preference for Reaction at Vacancy and Kink Sites. Z.Sljivančanin, B.Hammer: Physical Review B, 2002, 65[8], 085414 (4pp)