Interaction of aluminum with the Ru(0001) surface and its influence upon CO chemisorption

Journal Article · Thu May 05 04:00:00 EDT 1988 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100320a034· OSTI ID:6977843

Campbell, C T; Goodman, D W

The interaction of vapor-deposited Al with the Ru(0001) surface and its influence upon CO chemisorption has been studied in ultrahigh vacuum by use of Auger electron spectroscopy, thermal desorption mass spectroscopy, and low-energy electron diffraction (LEED). Below 670 K, the Al grows as an overlayer in (111) oriented islands. By 1170 K, Al penetrates the surface to form intermetallic compounds with the Ru, and a (root 3 x root 3)R30/sup 0/ LEED pattern dominates the surface structure. This is interpreted in terms of a stoichiometric monolayer of the compound Al/sub 2/Ru. Thermal desorption data indicate that this monolayer alloy has a heat of formation of about -24 kcal/mol, compared to -14 kcal/mol for the multilayer alloy which nucleates at higher coverages. The CO/Ru interaction at the surface of these intermetallic compounds is not very different from that on the clean Ru(0001) surface, except for the expected dilution of Ru sites by the added Al. In contrast, when the Al overlayer has not yet been annealed and the Al adatoms still sit on top of the Ru(0001) surface, they have a very strong influence upon CO desorption spectra. A new CO desorption state at 850-1050 K appears at submonolayer Al coverages, which is attributed to strong, direct, interaction between adsorbed CO and Al probably involving C-O bond cleavage.

• Research Organization: Indiana Univ., Bloomington (USA)
• OSTI ID: 6977843
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 92:9; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALUMINIUM
AUGER ELECTRON SPECTROSCOPY
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISORPTION
COHERENT SCATTERING
DATA
DIFFRACTION
DISSOCIATION
ELECTRON DIFFRACTION
ELECTRON SPECTROSCOPY
ELEMENTS
EXPERIMENTAL DATA
INFORMATION
MASS SPECTROSCOPY
METALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
RUTHENIUM
SCATTERING
SEPARATION PROCESSES
SORPTION
SPECTROSCOPY
TRANSITION ELEMENTS