H2 reactivity on strained pseudomorphic monolayers of Cu and Pd on Ru(0001)

The dissociative adsorption of H(2) on a strained pseudomorphic monolayer of Cu or Pd on a Ru(0001) substrate has been investigated by means of first-principles six-dimensional (6D) dynamics calculations. The results show that H(2) dissociation is similarly activated on Cu/Ru(0001) and Pd/Ru(0001), while it is nonactivated in Pd(111) and it is strongly activated in Cu(111). A comparison to anificially compressed Pd(111) and expanded Cu(111) shows that, apart from strain, substrate electronic effects play a very important role. Since these effects vary from site to site, a fully 6D analysis ofthe H(2)-surface interaction is necessary to understand the observed reactivity.