NO interaction with Cu(111) is shown to be dissociative for temperatures varying from 320 to 570 K and for exposures up to 150 Pa·s. Upon adsorption a saturation surface coverage (0.5 monolayer) of adsorbed oxygen and nitrogen is obtained. After an incubation period penetration of oxygen in subsurface layers is observed, leaving the surface coverage almost unchanged. Both the adsorption and the penetration are first order in the NO pressure, the reactions are not activated. The reduction of the adsorbate at 570 K proceeds in two stages, i.e. the net reduction of subsurface oxygen and the subsequent reduction of adsorbed oxygen. The rate of reduction strongly depends on the amount of adsorbed nitrogen and on the presence of subsurface oxygen. At a CO pressure exceeding 0.1 Pa reduction is followed by the desorption of nitrogen, probably via an isocyanate intermediate. From the reduction experiments and from experiments in which the isothermal desorption rate of nitrogen was measured it is concluded that adsorbed nitrogen interacts with adsorbed oxygen, resulting in a lower reactivity of oxygen and, possibly, nitrogen. This interaction is considerably weakened when also penetrated oxygen is present.@en

Absolute values for the chemisorption saturation coverages of oxygen on Cu(100), Cu(111) and Cu(110) surfaces were determined using nuclear reaction analysis and ellipsometry. The results support recently proposed structural models for oxygen on Cu(100). The chemisorption oxygen saturation coverage on Cu(111) amounts to about 0.3 ML.@en

The kinetics of the adsorption of NO and O2, and of the subsequent reduction with CO have been studied on the stepped copper surfaces Cu(711) and Cu(710). The surfaces exhibit terraces with the (100) structure, and steps with the (111) and the (110) structure, respectively. Gases were admitted at pressures ranging from 6 × 10 6 to 10 1 Pa, temperatures ranged from 370 to 670 K. Upon reaction, the adsorption sites and geometry are similar to those on Cu(100). The reactivity of the entire Cu(100) surface is increased by about an order of magnitude due to the presence of steps. The orientation of the steps only slightly affects the kinetics.@en

Exposure of NO or O2 to Cu(100) or Cu(110) (at temperatures between 370 and 670 K, pressures up to 0.1 Pa) leads to dissociative adsorption. Dissociation on Cu(110) is about an order of magnitude faster than on Cu(100). Saturation of the surface coverage (for both surfaces at about 0.42 monolayer) is followed by the structure-intensitive penetration of oxygen atoms into the crystal. Reduction proceeds via reaction of adsorped CO and adsorbed oxygen, the effect of nitrogen can be explained by site-blocking. Again, the reaction is about an order of magnitude faster on Cu(110) than on Cu(100). In the case of Cu(100) a transition from a disordered to an ordered overlayer is observed at a fractional surface coverage of about 0.3. Nitrogen desorption is more difficult from Cu(100) than from Cu(110). The desorption temperature depends on the presence of oxygen (adsorbed as well as penetrated). At high CO pressures the formation of isocyanate facilitates the desorption of nitrogen.@en