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Title:

Cyanide adlayers on Pt(111) in chloride containing electrolytes studied by in situ, ex situ IRAS and LEED

Document type:
Zeitschriftenaufsatz
Author(s):
Lennartz, M.; Arenz, M.; Stuhlmann, C.; Wandelt, K.
Abstract:
A new approach to studying the double layer properties at electrode surfaces is introduced by comparing in situ and ex situ IR reflection absorption spectroscopic (IRAS) results of a system prepd. under the same exptl. conditions. Cyanide adlayers on a Pt(111) electrode were studied in cyanide free 0.1M KCl soln. showing one single bipolar band around 2100 cm-1 and a Stark shift of 21 cm-1/V. This low tuning rate is explained by coadsorption of chloride in the cyanide adlayer, which results in a lower local elec. field effective in the double layer. After transfer to ultrahigh vacuum (UHV) the system also was studied by ex situ IRAS, LEED and Auger electron spectroscopy (AES). LEED pictures show two different adlayer structures depending on the emersion potential. After emersion at anodic potentials the known (2.sqroot.3 x 2.sqroot.3)R30°-CN structure is detected, whereas at cathodic potentials a (2 x 2)-CN structure could be obsd. The related FTIR spectra display a similar single band near 2110 cm-1 as in situ, with a clear dependence on the emersion potential, indicating a successful transfer to UHV. Therefore with ex situ IR spectroscopy the influence of the emersion potential on the C-N stretching vibration could be directly compared with the in situ measurements. [on SciFinder(R)]
Keywords:
Electron diffractometry (LEED (low energy electron diffractometry) cyanide adlayers on Pt(111) electrode in chloride contg. electrolytes studied by in situ, ex situ IRAS and LEED) Adsorption (coadsorption of chloride in cyanide adlayer in IR spectra study of cyanide adlayers on Pt(111) electrode in potassium chloride) Adsorbed substances (cyanide adlayers on Pt(111) electrode in potassium chloride studied by in situ, ex situ IR reflection absorption spectroscopy and LEED) IR spectra (of cyanide...     »
Congress title:
CAN 133:273222 72-2 Electrochemistry Institut fur Physikalische und Theoretische Chemie der Universitat Bonn, Bonn, Germany. Journal 0039-6028 57-12-5 (Cyanide) Role: PEP (Physical, engineering or chemical process), PRP (Properties), PROC (Process) (adlayers on Pt(111) electrode in potassium chloride studied by in situ, ex situ IR reflection absorption spectroscopy and LEED); 16887-00-6 (Chloride) Role: PEP (Physical, engineering or chemical process), PROC (Process) (coadsorption of chloride in...     »
Journal title:
Surf. Sci.
Year:
2000
Journal volume:
461
Journal issue:
1-3
Pages contribution:
98-106
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