Low-energy electron diffraction and density-functional theory calculations
are used to examine the adsorption properties of CO and N-2 On RuO2(110). B
oth molecules adsorb over the coordinatively unsaturated Ru sites (cus-Ru a
toms) with their molecular axes normal to the surface plane. The chemisorpt
ion mechanism is well described within a donor-acceptor model, i.e., the Bl
yholder model. Since N-2 is not reacting with lattice oxygen of RuO2, quite
in contrast to CO, N-2 may serve as a chemical, nondestructive probe to ti
trate but also to selectively block the cus-Ru atoms; recently, the cus-Ru
atoms were shown to be the active centers for the chemisorption of molecule
s.