TY - JOUR
T1 - Reduction of nitric acid on Ag in ultrahigh vacuum
T2 - A Raman spectroscopic investigation
AU - Zangmeister, Christopher D.
AU - Davis, Robert J.
AU - Mrozek, Pawel
AU - Pemberton, Jeanne E.
N1 - Funding Information:
The authors gratefully acknowledge the National Science Foundation (CHE-0317114) for financial support of this research. Financial support for CDZ was also provided by a fellowship from the American Chemical Society Division of Analytical Chemistry sponsored by the Society of Analytical Chemists of Pittsburgh.
PY - 2008/7/15
Y1 - 2008/7/15
N2 - The reduction of HNO3 on Ag as a function of temperature in ultrahigh vacuum (UHV) is studied using Raman spectroscopy and thermal desorption-mass spectrometry (TDMS). Thin layers of molecular HNO3 are stable on the surface below 150 K, but are spontaneously reduced above 150 K with concomitant time-dependent partial desorption of products. The asymmetric nitric oxide dimer, NONO, is observed as the sole reduction product that remains on the surface based on its distinctive Raman spectral signature. The mechanism of NONO formation from HNO3 is proposed to occur through a multistep reduction of HNO3 on the Ag surface starting from NO3- and proceeding stepwise through NO2 and NO2- to NO, followed by combination to form NONO in a process catalyzed by a Lewis acid, oxidized Ag species. Desorption of the majority of surface species is largely complete by 210 K.
AB - The reduction of HNO3 on Ag as a function of temperature in ultrahigh vacuum (UHV) is studied using Raman spectroscopy and thermal desorption-mass spectrometry (TDMS). Thin layers of molecular HNO3 are stable on the surface below 150 K, but are spontaneously reduced above 150 K with concomitant time-dependent partial desorption of products. The asymmetric nitric oxide dimer, NONO, is observed as the sole reduction product that remains on the surface based on its distinctive Raman spectral signature. The mechanism of NONO formation from HNO3 is proposed to occur through a multistep reduction of HNO3 on the Ag surface starting from NO3- and proceeding stepwise through NO2 and NO2- to NO, followed by combination to form NONO in a process catalyzed by a Lewis acid, oxidized Ag species. Desorption of the majority of surface species is largely complete by 210 K.
KW - Nitrogen oxides
KW - Raman scattering spectroscopy
KW - Surface chemical reaction
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U2 - 10.1016/j.susc.2008.05.006
DO - 10.1016/j.susc.2008.05.006
M3 - Article
AN - SCOPUS:48149087574
SN - 0039-6028
VL - 602
SP - 2395
EP - 2401
JO - Surface Science
JF - Surface Science
IS - 14
ER -