THEORETICAL CLUSTER MODEL STUDIES OF BIMETALLIC HETEROGENEOUS CATALYSIS - DISSOCIATION OF HYDROGEN ON A RHENIUM-DOPED NICKEL CLUSTER

An investigation has been undertaken of the system ReNi12H2, as a mode l for dissociation reactions on a rhenium-doped heterogeneous catalyst . Our results are compared to earlier studies on the systems Ni13H2 an d ReH2. The surrounding cluster substantially increases the Re reactiv ity relative to the bare metal atom. The enhanced reactivity is due to the stabilization of states of lower multiplicity on the rhenium atom as its d electrons participate in bonding to the cluster. Comparing w ith the ''undoped'' nickel cluster, we note that the chemisorption ene rgy is only slightly shifted. There are however interesting difference s in the bonding mechanisms.