1D Pd-Based Nanomaterials as Efficient Electrocatalysts for Fuel Cells - Low-cost Nanomaterials: Toward Greener and More Efficient Energy Applications - page 328

Fig. 9 SEM micrographs of a and b surface of Pd NWAs, c surface of Pd/Pt core-shell NWAs,
d cross-section of Pd NWAs, and e cross-section of Pd/Pt core-shell NWAs. Reprinted from
Ref. [ 72 ] with permission by Elsevier
Earlier studies have shown that 1D NWs have a strong interaction with carbon
supports and are less vulnerable than conventional nanoparticles to dissolution,
Ostwald ripening, and aggregation in strong acidic electrocatalytic conditions
[ 71 , 103 ]. Different from the bimetallic Pd-based alloys, Guo et al. [ 104 ] recently
synthesized ultrathin (2.5 nm) trimetallic FePtPd alloy nanowires (NWs) with
tunable compositions and controlled length (less than 100 nm). These FePtPd
NWs exhibited composition-dependent catalytic activity and stability for methanol
oxidation reaction. As shown in Fig. 11 a, the as-prepared Fe 28 Pt 38 Pd 34 NWs
exhibit the highest catalytic activity for methanol oxidation with the mass current
density of 488.7 mA mg P -1 and peak potential decreased from 0.665 V (vs. Ag/
AgCl) obtained on Pt nanoparticle catalysts to 0.614 V. More interestingly, the
Fe 28 Pt 38 Pd 34 displayed enhanced electrochemical stability with the mass current
density (98.1 mA mg P -1 ) after i-t test for 2 h at 0.4 V (Fig. 11 b). Figure 11 c, d
indicates that there was almost no noticeable morphology change before and after
i-t tests, whereas the Pt nanoparticles experienced substantial aggregation. The
authors attributed the enhanced stability of NWs versus NPs to the stronger NW
interactions with carbon support and/or by better NW structure stability, which