Accession Number:

ADA169081

Title:

Electrode/Electrolyte Interphase Study Using Polarization Modulated FT-IR Reflection Absorption Spectroscopy.

Descriptive Note:

Technical rept.,

Corporate Author:

IBM ALMADEN RESEARCH CENTER SAN JOSE CA

Report Date:

1986-05-16

Pagination or Media Count:

24.0

Abstract:

The polarization modulated Fourier transform infrared reflection-absorption spectroscopy FT-IRRAS is applied to the studies of adsorption and oxidation of Carbon monoxide CO on a platinum electrode in 0.5M sulfuric acid and of adsorption of cyanide on gold and silver electrodes in 0.5M sulfuric potassium sulfate. The absorption intensity of the CO on platinum electrode is ca. 4-5 while that of the CN- on silver and gold is 0.2-0.5. The potential dependence of the vibrational spectra was observed for both systems. Oxidation of the linearly adsorbed CO layer proceeds by different mechanisms depending on whether CO was adsorbed at a potential in the double layer region or in the hydrogen region, i.e., at the edges of the CO islands in the former case and randomly in the latter case, in which the bridged CO species plays and important role. The vibrational frequency of the linearly adsorbed CO changes linearly with potential at a rate of 30 cm-1volt, which is independent of anion specific adsorption. The origin of the shift is most reasonably explained by the first order Stark effect. For Ag, AuCN- systems, the surface cyanide species is the linearly adsorbed CN-. The anodic reaction products in the solution from cyanide ions and the electrode are also observed in the vibrational spectra. The bands due to surface species and those due to solution species are distinguished by measuring the spectra with s and p-polarized lights.

Subject Categories:

  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE