Adsorption and interaction of carbon monoxide (CO) and nitric oxide (NO) molecules on the surface of bare Al-Mo(110) system and on that obtained by its in situ oxidation have been studied in ultra-high vacuum (base pressure: ca. 10⁻⁸ Pa) by means of Auger and X-ray photoelectron spectroscopy (AES, XPS), low energy electron diffraction (LEED), reflection–absorption infrared and thermal desorption spectroscopy (RAIRS, TDS), and by the work function measurements. In order to achieve the Al-Mo(110) alloy the thin aluminum film of a few monolayers thick was in situ deposited onto the Mo(110) crystal and then annealed at 800 K. As a result of Al atoms diffusion into the Mo(110) subsurface region and the chemical reaction, the surface alloy of a hexagonal atomic symmetry corresponding to Al₂Mo alloy is formed. The feature of thus formed surface alloy regarding molecular adsorption is that, unlike the bare Mo(110) and Al(111) substrates, on which both CO and NO dissociate, adsorption on the alloy surface is non-dissociative. Moreover, adsorption of carbon monoxide dramatically changes the state of pre-adsorbed NO molecules, displacing them to higher-coordinated adsorption sites and simultaneously tilting their molecular axis closer to the surface plane. After annealing of this coadsorbed system up to 320 K the (CO + NO → CO₂ + N) reaction takes place resulting in carbon dioxide desorption into the gas phase and nitriding of the substrate. Such an enhancement of catalytic activity of Mo(110) upon alloying with Al is attributed to surface reconstruction resulting in appearance of new adsorption/reaction centers at the Al/Mo interface (steric effect), as well as to the Mo d-band filling upon alloying (electronic effect). Catalytic activity mounts further when the Al-Mo(110) is in situ oxidized. The obtained Al-Mo(110)-O ternary system is a prototype of a metal/oxide model catalysts featuring the metal oxides and the metal/oxide perimeter interfaces as a the most active reaction sites. As such, this type of low-cost metal alloy oxide models precious metal containing catalysts and can be viewed as a potential substitute to them.

Auger electron spectroscopy has been used to study the kinetics of oxygen adsorption on lead for two cases, i.e., during continuous electron irradiation (0–1000 eV) and without it, depending on exposure to oxygen at a partial pressure of 10⁻⁶ Torr and room temperature. The maximum exposure to oxygen is 5000 L. Lead exposure to oxygen of several hundred Langmuirs with simultaneous irradiation with low-energy electrons shifts Auger lead peaks by 1 eV toward lower energies, which is explained by electron-stimulated adsorption (ESA). It has been shown that ESA is observed only at electron energies below 300 eV; at higher energies, electron-stimulated desorption of oxygen dominates.

The results from investigating the surface characteristics of liquid sodium, potassium, and four potassium–sodium alloys are considered. The Auger spectra and profiles of metal droplets with atomically pure surfaces in the solid and liquid state are studied under the same experimental conditions. It is shown that potassium is a surfactant with respect to sodium at the temperature of an experiment in the investigated range of volume concentrations. It is noted that the obtained values of surface tension are 15% higher than the reference values.

Surface layers of polycrystalline silver bombarded with oxygen ions having energies from 100 to 300 eV are studied via Auger electron and X-ray photoelectron spectroscopies. Atomic and...

The physical and chemical properties of materials are greatly influenced by the state of their surface layers. In turn, the characteristics of the surface depend, for example, on the...