Underpotential deposition of Cu on Au(111) in sulfate-containing electrolytes: A theoretical and experimental study

Journal Article · Mon Apr 01 04:00:00 EST 1996 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.471769· OSTI ID:283415

Zhang, J ^[1]; Sung, Y ^[2]; Rikvold, P A ^[1]; Wieckowski, A ^[2]

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1. Supercomputer Computations Research Institute, Florida State University, Tallahassee, Florida 32306-4052 (United States)
2. Department of Chemistry and Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States)

We study the underpotential deposition of Cu on single-crystal Au(111) electrodes in sulfate-containing electrolytes by a combination of computational statistical-mechanics based lattice-gas modeling and experiments. The experimental methods are {ital in} {ital situ} cyclic voltammetry and coulometry and {ital ex} {ital situ} Auger electron spectroscopy and low-energy electron diffraction. The experimentally obtained voltammetric current and charge densities and adsorbate coverages are compared with the predictions of a two-component lattice-gas model for the coadsorption of Cu and sulfate. This model includes effective, lateral interactions out to fourth-nearest neighbors. Using group-theoretical ground-state calculations and Monte Carlo simulations, we estimate effective electrovalences and lateral adsorbate{endash}adsorbate interactions so as to obtain overall agreement with experiments, including both our own and those of other groups. In agreement with earlier work, we find a mixed ({radical}3{times}{radical}3) phase consisting of 2/3 monolayer Cu and 1/3 monolayer sulfate at intermediate electrode potentials, delimited by phase transitions at both higher and lower potentials. Our approach provides estimates of the effective electrovalences and lateral interaction energies, which cannot yet be calculated by first-principles methods. {copyright} {ital 1996 American Institute of Physics.}

• Research Organization: University of Illinois
• DOE Contract Number: AC02-76ER01198; FG05-85ER25000
• OSTI ID: 283415
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 14 Vol. 104; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ADATOMS
ADSORPTION
COPPER
DEPOSITION
ELECTRIC POTENTIAL
ELECTROCHEMISTRY
ELECTRODES
ELECTROLYTES
GOLD
INTERFACES
MONOLAYERS
SURFACE STRUCTURE