1D Pd-Based Nanomaterials as Efficient Electrocatalysts for Fuel Cells - Low-cost Nanomaterials: Toward Greener and More Efficient Energy Applications - page 320

Fig. 3 a Loss of
electrochemical surface area
(ECSA) of Pt/C (E-TEK),
platinum-black (PtB;
E-TEK), and PtNT catalysts
with number of CV cycles in
Ar-purged 0.5 M H 2 SO 4
solution at 60 C (0-1.3 V
vs. RHE, sweep rate
50 mV s -1 ). b ORR curves
(shown as current-voltage
relations) of Pt/C, platinum
black (PtB), PtNTs, and
PdPtNTs in O 2 -saturated
0.5 M H 2 SO 4 solution at
room temperature (1600 rpm,
sweep rate 5 mV s -1 ). Inset
mass activity (top) and
specific activity (bottom) for
the four catalysts at 0.85 V.
Reprinted from Ref. [ 75 ]
with permission by Wiley-
VCH

platinum-black and Pt/C catalysts lose about 51 and 90 % of their ECSA,
respectively. However, the Pt nanotubes only lose about 20 % of its ECSA,
indicating the enhanced electrochemical stability of the unsupported nanotubes. In
addition, the durability tests indicated that the ECSA of PtPd NTs is 5.8 times
higher than that of the Pt/C and 1.5 times higher than that of the Pt NTs. Such
enhanced activity and durability of PtPd NTs toward ORR can be ascribed to the
change of electronic structures induced by the addition of Pd into the platinum
lattice.
The electrocatalytic results obtained from the Pt and PtPd nanotubes clearly
indicated that the catalytic performance of 1D nanomaterials can be improved by
decorating another metal. Recently, Alia et al. [ 79 ] synthesized Pt-coated Pd
nanotubes (Pt/PdNTs) with a wall thickness of 6 nm, outer diameter of 60 nm, and
length of 5-20 lm via the partial galvanic displacement of Pd nanotubes with Pt.
ORR on Pt/PdNTs, Pt nanotubes (PtNTs), Pd nanotubes, and supported Pt nano-
particle

was studied to evaluate their electrocatalytic activities as PEMFCs