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Dana D. Dlott (Curriculum Vitae) Dana D. Dlott (personal home page) David M. Dlott (personal home page) |
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Time-resolved
spectroscopy at a working electrochemical fuel cell This work is a collaborative effort between the Dlott spectroscopy group and the Wieckowski
electrochemistry group. Despite the importance of electrochemical phenomena
in power storage and power generation, the detailed behavior of molecules at
electrodes is still a mystery.
Vibrational sum-frequency generation spectroscopy is a powerful tool
for studying molecules at electrode surfaces or in the electrolyte
immediately adjacent to the electrode, in real time. Prior to our collaboration some work in this area
had been performed using 1st generation SFG apparatus, which
acquire spectra step-by-step. The slow
data acquisition rate and need for a very thin electrolyte layer can
significantly distort the spectrum and cannot be used for fast kinetic measurements. Our 2nd generation spectrometer, using
broadband multiplex detection can obtain complete SFG spectra in less than
0.2 s, even when the electrolyte is thick enough (typically 25 mm to 75 mm) to provide low resistance and fast time constants
needed for kinetic measurements. Present work is focused at studying CO on
single-crystal and mixed metal nanoisland electrodes used in fuel cells. Future work will include studies of the
decomposition of fuels at the electrode surface. References “Quantitative vibrational sum-frequency generation spectroscopy of thin
layer electrochemistry: CO on a Pt
electrode”, G. Q. Lu, A. S. Lagutchev, D. D. Dlott and A.
Wieckowski, Surf. Sci. 585 pp.
3-16 (2005). “The mature
years of Sum-Frequency Generation are ahead”, P. Guyot-Sionnest, Surf.
Sci. 585, 1-2 (2005). |
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Second-generation SFG spectrometer acquires data rapidly using broadband multiplex approach.
A time series of CO spectra on a polycrystalline Pt electrode (electrolyte 0.1M sulfuric acid) obtained during a potentiometric scan.
SFG data obtained with CO/Pt with a CO-saturated electrolyte. |
