title: Nitrate adsorption and reduction on Cu(100) in acidic solution.
abstract: Nitrate adsorption and reduction on Cu(100) in acidic solution is studied by electrochemical methods, in situ electrochemical scanning tunneling microscopy (EC-STM), surface enhanced Raman spectroscopy (SERS), and density functional theory (DFT) calculations. Electrochemical results show that reduction of nitrate starts at -0.3 V vs Ag/AgCl and reaches maximum value at -0.58 V. Over the entire potential region interrogated adlayers composed of nitrate, nitrite, or other intermediates are observed by using in situ STM. From the open-circuit potential (OCP) to -0.22 V vs Ag|AgCl, the nitrate ion is dominant and forms a (2 x 2) adlattice on the Cu(100) surface while nitrate forms a dominantly c(2 x 2) structure from -0.25 to -0.36 V. The interconversion between the nitrate and nitrite adlattices is observed. DFT calculations indicate that both nitrate and nitrite are twofold coordinated to the Cu(100) surface.
authors.affiliation: Department of Chemistry, University of Illinois, Urbana, Illinois 61801, USA.
authors.forename: Sang-Eun
authors.initials: SE
authors.lastname: Bae
authors.forename: Karen L
authors.initials: KL
authors.lastname: Stewart
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Gewirth