Adsorption states of dinitrogen on small tungsten nanoclusters

Adsorption states of dinitrogen (N2) on small tungsten nanoclusters (Wn, n = 2–6) have been studied by density functional theory calculations. It has been found that among molecular adsorption states, a weakly bound state with an end-on type geometry is the most energetically favorable for all the nanoclusters. However, for a tetramer or larger nanoclusters, there is at least one meta-stable molecular state with a W–N–N–W bridge-type geometry and a highly activated N–N bond. By way of the bridge-type states, N2 may dissociate, or react with other molecules.