Z.-Y. Zhou et al. / Electrochimica Acta 55 (2010) 7995–7999
7999
solution, especially in the potential region of −0.25 to 0.0 V, may
affect the selectivity of ethanol oxidation to CO2. Future research
will be needed to confirm it by decreasing ethanol concentration.
The present study indicates that pure Pd is a low efficient elec-
trocatalyst for ethanol oxidation in alkaline solutions, and further
exploration of Pd-based alloy catalysts with high ability to break
the C–C bond could be important for alkaline direct ethanol fuel
cells.
Acknowledgments
This study was supported by NSFC (20933004, 20833005 and
20873113), the MOST (2007DFA40890), the Research Fund for New
Teachers of the Doctoral Program of Higher Education of China
(Grant No. 200803841035), and Fujian Provincial Department of
Science and Technology (2008I0025 and 2008F3099).
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In this paper, the oxidation of ethanol on a polycrystalline Pd
electrode in 0.1 M NaOH solution was studied by means of cyclic
voltammetry and in situ FTIR reflection spectroscopy together with
transmission FTIR spectroscopy. The cyclic voltammetric studies
indicate that the oxidation of ethanol gives current peaks at −0.21
and −0.29 V in the positive- and negative-going potential scan,
respectively. FTIR spectroscopic studies demonstrated that the oxi-
dation of ethanol is quite incomplete on Pd electrode, and the main
product is acetate. Through quantitative analysis of in situ FTIR
spectra, the selectivity for ethanol oxidation to CO2 was determined
to be less than 2.5% in the potential region of −0.60 to 0 V. Although
this value is very low, it is still slightly higher than that of Pt. It is
also worth noticing that the depletion of NaOH in the thin-layer