ADSORPTION OF NO ON NI(100)

The adsorption of NO on Ni(100) at different coverages and temperatures has been studied using high-resolution XPS. The core level shifts are discussed using the Z + 1 approximation and interpreted in relation to different adsorption geometries. It is concluded that the N 1s binding energy is sensitive to the molecular angle relative to the surface whereas the O 1s binding energy is more sensitive to the adsorption site. A lying-down low-coverage species was found to dissociate between 150 and 180 K whereas the onset for dissociation of a perpendicularly oriented high-coverage species was between 200 and 240 K.