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Author Adzic, R. R. ♦ Wang, J. X. ♦ Magnussen, O. M. ♦ Ocko, B. M.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ CHEMISTRY ♦ TANTALUM ♦ ADSORPTION ♦ ELECTRODEPOSITION ♦ FILMS ♦ X-RAY DIFFRACTION ♦ ACID SULFATES ♦ PLATINUM ♦ ELECTRODES ♦ SURFACES ♦ PH VALUE ♦ VOLTAMETRY
Abstract The structure of Tl adlayers deposited at underpotentials on Pt(111) has been investigated in four different electrolyte solutions (HClO{sub 4}, NaClO{sub 4}, NaOH, and H{sub 2}SO{sub 4}) with surface X-ray scattering (SXS) techniques. In all solutions investigated, Tl forms an incommensurate, aligned-hexagonal phase at the most negative potentials prior to its bulk deposition or hydrogen evolution. With decreasing potential the monolayer compresses and thus the Tl coverage increases. Under hydrogen evolution, the close-packed hexagonal Tl monolayer also exists and this reaction causes a slight lowering of the Tl coverage and a significant decrease of the in-plane ordering of the monolayer. In sulfuric acid solution, besides the close-packed hexagonal phase, a commensurate ({radical}3 x {radical}3)R30{degree} phase with a Tl coverage of 1/3 monolayer is formed in coadsorption with bisulfates over a 0.22 V wide potential range. 21 refs., 8 figs.
ISSN 00223654
Educational Use Research
Learning Resource Type Article
Publisher Date 1996-08-29
Publisher Department Brookhaven National Laboratory (BNL), Upton, NY
Publisher Place United States
Journal Journal of Physical Chemistry
Volume Number 100
Issue Number 35
Organization Brookhaven National Laboratory (BNL), Upton, NY


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