Reactivity of ultrathin-film solid HNO3 on Ag by surface Raman spectroscopy

ANYL 105

Robert J. Davis, rjdavis@email.arizona.edu and Jeanne A. Pemberton. Department of Chemistry, University of Arizona, 1306 East University Blvd, Tucson, AZ 85721
The reduction of ultrathin films of molecular HNO3 that are vapor-deposited onto cooled Ag substrates is reported. Ultrathin films of HNO3 of 1 to 10 monolayer thickness were deposited onto Ag at 60K in UHV and monitored using surface Raman spectroscopy. Raman spectroscopy is inherently sensitive to NOx species and is used to study the subsequent reduction and formation of products at the interface as a function of both temperature and time. The reduction of nitric acid is kinetically-controlled at low temperature (60K), and a novel end product for nitrate reduction, the asymmetric N2O2 (N-O-N-O), is observed. Evidence for a surface-catalyzed dimerization of NO, the primary product of HNO3 reduction, is presented and probable mechanisms are discussed.
 

General Papers
7:00 PM-9:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster

Division of Analytical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006