Abstract
Broad-band sum frequency generation spectroscopy (BB-SFG) was used to obtain vibrational spectra of CO adsorbates produced from formic acid oxidation on a Pt (1 0 0) electrode in sulfuric acid media. The BB-SFG simultaneously monitored all forms of the CO intermediates, including steady-state, as the potential was scanned at 5 mV/s. Spectra were compared to those obtained from CO adsorbed from a CO-saturated electrolyte. While adsorbed from HCOOH, the CO had a sharp atop transition near 2050 cm -1 and a broader multiply-bonded transitions in the 1700-1900 cm -1 range, which appear to result from bridge-like and higher-coordinated (possibly fourfold) CO. As the potential scanned from -0.2 to 0.3 V (vs. Ag/AgCl), the bridge-like CO disappeared, and the amount of atop CO increased. At potentials above 0.5 V, the CO was in steady-state, being oxidized on the surface to CO 2 and replenished by CO from HCOOH. These measurements show that BB-SFG can observe potential-dependent interconversion of different CO forms on the electrode surface and can measure steady-state reaction intermediates on a surface in real time.
Original language | English (US) |
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Pages (from-to) | 32-36 |
Number of pages | 5 |
Journal | Journal of Electroanalytical Chemistry |
Volume | 649 |
Issue number | 1-2 |
DOIs | |
State | Published - Nov 15 2010 |
Keywords
- Broad-band sum frequency generation (BB-SFG)
- CO adsorbates
- Electrochemistry
- Formic acid oxidation
- Platinum 100
- Vibrational spectroscopy
ASJC Scopus subject areas
- Chemical Engineering(all)
- Analytical Chemistry
- Electrochemistry