H2 dissociation at defected Cu: Preference for reaction at vacancy and kink sites

H2 dissociation at defected Cu: Preference for reaction at vacancy and kink sites

by Z. Sljivancanin and B. Hammer.

Phys. Rev. B 65, 085414 (2002).

Abstract

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