Chemical properties of bimetallic surfaces: The reaction of O[sub 2] and NO[sub 2] with Zn on Ru(001)

Journal Article · Thu Jun 17 00:00:00 EDT 1993 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100126a029· OSTI ID:6078204

Rodriguez, J A ^[1]

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1. Brookhaven National Lab., Upton, NY (United States)

The dissociation of O[sub 2] and NO[sub 2] on Zn/Ru(001) surfaces and the properties of the resulting ZnO[sub x] adlayers have been investigated using TDS, XPS, and XAES. For submonolayer coverages of O and Zn on Ru(001), there is no lateral bonding between the adatoms. In these cases, strong Ru [leftrightarrow] O and Ru [leftrightarrow] Zn interactions prevent the formation of Zn-O bonds. ZnO[sub x] films were observed after increasing the Zn and O coverage above 1 monolayer. Some of these films displayed the typical O(1s) XPS and Zn L[sub 3]M[sub 45]M[sub 45] Auger spectra of polycrystalline ZnO, decomposing at temperatures between 800 and 1,050 K. At 80 K, the initial dissociation probability of O[sub 2] on Zn[sub 1.0]/Ru(001) is almost 2 orders of magnitude smaller than that on polycrystalline Zn. This reduction in the rate of O[sub 2] dissociation is accompanied by a change in the type of oxygen formed: for the supported Zn monolayer, surface oxygen predominates; whereas for pure Zn, oxygen incorporated into the bulk of the film is the dominant species. The dissociation of NO[sub 2] is similar on Zn[sub 1.0]/Ru(001) and polycrystalline Zn. At 80 K, the initial NO[sub 2] adsorption is dissociative: NO[sub 2,g] [yields] NO[sub g] + O[sub a]. The oxygen adatoms passivate the surface, and the subsequent adsorption of NO[sub 2] is molecular. Chemisorbed NO[sub 2] decomposes at temperatures between 160 and 250 K to yield gaseous NO and oxygen atoms that remain on the surface (Zn[sub 1.0]/Ru(001) case) or migrate into the bulk (pure Zn case). At 300 K, the probability for dissociation of NO[sub 2] on Zn surfaces is 2 orders of magnitude larger than the probability for dissociation of O[sub 2]. 61 refs., 14 figs., 1 tab.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6078204
• Journal Information: Journal of Physical Chemistry; (United States), Vol. 97:24; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
RUTHENIUM
SURFACES
CHEMICAL PROPERTIES
ZINC
ADSORPTION
AUGER ELECTRON SPECTROSCOPY
DISSOCIATION
MASS SPECTROSCOPY
NITROGEN OXIDES
OXYGEN
SPECTROSCOPY
ZINC OXIDES
CHALCOGENIDES
ELECTRON SPECTROSCOPY
ELEMENTS
METALS
NITROGEN COMPOUNDS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
SORPTION
TRANSITION ELEMENTS
ZINC COMPOUNDS
400201* - Chemical & Physicochemical Properties
400102 - Chemical & Spectral Procedures