Coverage dependence of N2 dissociation at an N, O, or H precovered Ru(0001) surface investigated with density functional theory -: art. no. 205423

The coverage dependence of the dissociative N-2 adsorption reaction at a precovered Ru(0001) surface is investigated by means of density functional theory calculations. The energy barrier for N-2 dissociation increases with the N-a or O-a precoverage and, to a lesser extent, with the H-a precoverage. The stability of the reaction products, 2N(a), decreases monotonically with the precoverage. The coverage dependent Ru 4d-band center in energy, epsilon (d), at the reaction site, is shown to control the energy barrier and reaction energy. The results are thereby explained in terms of a substrate mediated interaction between the dissociating N-2 and the adsorbates.