Dissociative Adsorption Dynamics of H2(D2) on Metal Alloy Surfaces - A First Step Towards Surface Reaction Design/Control -

We report on how we can influence the dynamics of H 2 dissociation by changing the orientation dependence of the reaction. To demonstrate, we examined H 2 dissociation across the Cu-Pt bridge site of an ordered Cu 3 Pt(111). Our density-functional-theory-based potential energy surface calculation results reveal a considerable activation barrier, with an orientation dependence that exhibits preference for H 2 orientations parallel to the surface over all other orientations, and preference for H 2 orientations perpendicular to the surface over orientations intermediate between perpendicular and parallel. Our calculated dissociation probability results reveal nonmonotonic dependence on the initial rotational state of the impinging H 2 , and we suggest how further information regarding the orientation dependence of the reaction could be determined experimentally.