Simple Synthesis of Au–Pd Alloy Nanowire Networks as Macroscopic, Flexible Electrocatalysts with Excellent Performance

Abstract

The present work introduces a new way to prepare Au-Pd alloy nanowire networks (NWNs) via deposition of Pd atoms onto Au nanowires in reaction media at room temperature without the aid of additional reducing agents. Thanks to their excellent colloidal stability in water as well as in ethanol, the resulting NWNs can be utilized to produce composite thin films with Nafion (perfluorinated sulfonic acid) with dimensions above dozens of square centimeters by means of solution casting on the glass substrate. Most importantly, these films can be easily transferred onto different solid substrates by lift-off technology. Moreover, the resulting Au-Pd alloy NWNs can also be easily and thoroughly loaded into macroscopic carbon fiber cloth (CFC). Both the Au-Pd alloy NWN/Nafion composite film and the Au-Pd alloy NWN-loaded CFC can be used as flexible electrodes for electrocatalysis of ethanol oxidation, with electrocatalytic performance at different distorted states superior by 2 orders of magnitude to those reported in the literature (e.g., commercial Pd/C catalysts and Pd-based nanostructured catalysts). This work opens new possibilities for the large-scale manufacturing of electrodes for fuel cells.

Unveiling reductant chemistry in fabricating noble metal aerogels for superior oxygen evolution and ethanol oxidation

“…The electrocatalytic ethanol oxidation, serving as a model reaction that takes place at the anode of direct ethanol fuel cells, has been extensively studied by using a wide range of Pd-based and Pt-based NMAs 6,7 and nanowire networks 44,45 . EOR tests of commercial Pd/C were performed together with those on the Pd aerogel, Au-Pd aerogel, and Au-Pd NPs (Fig.…”

Platinum Group Nanowires for Efficient Electrocatalysis

“…Besides Pt‐based alloy nanowires, other alloy nanowires were also obtained in Pd‐ and Ir‐based nanowires ( Table 4 ). For Pd‐based nanowires, Pd–Ag, Pd–Au, and Pd–Ni alloy nanowires have been successfully prepared . There are only a few reports on Ir‐based nanowires .…”

“…The oxygen absorption energies of these four kinds of sites are closer to the optimal E O value. For Pt 3 Co nanowires, threefold hollow sites on both and missing‐row reconstructed [310] surfaces were highly active for ORR (Figure c) …”

“…For Pd-based nanowires, Pd-Ag, Pd-Au, and Pd-Ni alloy nanowires have been successfully prepared. [107][108][109] There are only a few reports on Ir-based nanowires. [110] For example, Ir-Sn nanowires were successfully prepared by Zhu et al, using iridium(III) chloride hydrate (IrCl 3 ) and tin(II) acetate (Sn(Ac) 2 ) Small Methods 2019, 3,1800545 as metal precursors, citric acid (CA) as the reducing agent, PVP as the reducing agent, and EG as the solvent and reducing agent.…”

“…[30] The oxygen absorption energies of these four kinds of sites are closer to the optimal E O value. For Pt 3 Co nanowires, threefold hollow sites on both [108] and missing-row reconstructed [310] surfaces were highly active for ORR (Figure 11c). [26] Cu is also studied for generating the Pt alloy nanowires with high-density low-coordinated atoms, which show much higher ORR activity than the pure Pt nanowires.…”