74
6.6 Formic Acid Oxidation Reaction
Formic acid (FA) is an attractive fuel for fuel cells because of its high-energy density and easy storage. Direct formic acid fuel cells (DFAFC) have higher potential
for miniaturization because of their high-power output compared to other liquid fuel
0.6
0.6
0.4
0.3
0.2
0.1
E
versus
RHE (V)
E versus RHE (V)
–4
–3
–2
–1
0
Log j (mA cm
–2
)
2,400
2,000
1,600
1,200
Wavenumber (cm
–1 )
0.001
Absorbance
0.32
0.44
0.55
0.67
0.79
0.83
0.71
0.60
0.68
0.36
1,110
1,277
1,391
1,715
2,342
(a)
(b)
PtRhSnO 2 /C
Pt/C (E-TTEK)
Fig. 6.3 (a) Quasi-steady-state polarization curves for oxidation of ethanol on ternary PtRhSnO 2 /C
and Pt/C electrocatalysts and (b) in situ infrared spectra in 0.1 M HClO 4  + 0.2 M C 2 H 5 OH. (From
Ref. [73] with permission)
1.2
1.0
0.8
0.6
0.4
0.2
0.0
11200
11400
11600
11800
Energy / eV
Normalized Absorption / a.u.
Normalized Absorption / a.u.
E / V vs RHE
0.41V
0.71V
0.91V
1.11V
E / V vs RHE
0.41V
0.71V
0.91V
1.11V
Ir L3 edge
Ir L3 edge
Pt L3 edge
Pt L3 edge
1.2
1.0
0.8
0.6
0.4
0.2
0.0
11200
11220
11240
11260
11280
Energy / eV
Normalized Absorption / a.u.
E / V vs RHE
0.41V
0.71V
0.91V
1.11V
1.2
1.0
0.8
0.6
11560
11580
11600
11620
Energy / eV
Fig. 6.4 In situ XANES spectra of Pt L 3 and Ir L 3 edges of PtIr/SnO 2 /C electrocatalyst under different applied potentials. (From [79] with permission)
6 Important Electrocatalytic Reactions