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Phase Transitions in Electrochemical Adsorption

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P. A. Rikvold and A. Wieckowski

In *Thin Films and Phase Transitions on Surfaces;
Proceedings of the Second East-West Surface Science
Workshop, EWSSW96, Pamporovo, Bulgaria, February 18-24, 1996*,
edited by M. Michailov
(Institute of Physical Chemistry,
Bulgarian Academy of Sciences, Sofia, 1996), pp. 58-75.
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Abstract

A technique of statistical-mechanical lattice-gas modeling
of chemisorption, applicable to electrochemical systems
dominated by lateral interactions, is reviewed.
A strategy for applying
the method to specific systems is outlined. This includes
microscopic model formulation, calculation of zero-temperature phase
diagrams, numerical calculation of thermodynamical
and structural quantities at nonzero temperatures,
and estimation of the effective, lateral interaction energies.
The general discussion is illustrated by applications to the following
specific problems.
The poisoning by sulfur
of hydrogen adsorption on platinum (111),
the electrochemical adsorption
of organics on polycrystalline copper and nickel and of urea
on single-crystal
platinum (100), and the underpotential deposition of
copper on single-crystal gold (111).