Atom-stepped surface-regulated Pd nanowires for boosting alcohol oxidation activity

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Highly active surfaces are crucial for electrocatalyst performance.
• Tailoring atomic packing and surface characteristics of electrocatalysts remains a challenge.
• Ethanol oxidation reaction (EOR) and ethylene glycol oxidation reaction (EGOR) are key anode reactions for direct alcohol fuel cells (DAFCs).

Purpose of the Study:

• To synthesize penta-twinned palladium (Pd) nanowires with abundant high-energy atomic steps.
• To investigate the electrocatalytic activity and stability of these stepped Pd nanowires for EOR and EGOR.
• To demonstrate a strategy for creating mono- and bimetallic nanowires with atomic steps.

Main Methods:

• Seeded synthesis of penta-twinned Pd nanowires on Pd nanowires enclosed by (100) facets.
• Characterization of atomic packing and surface structures, including atomic steps like [n(100) × m(111)].
• Electrochemical evaluation of catalytic activity and stability for EOR and EGOR compared to commercial Pd/C and non-stepped Pd nanowires.

Main Results:

• Stepped Pd nanowires exhibit enhanced catalytic activity and stability for EOR and EGOR compared to commercial Pd/C and Pd nanowires enclosed by (100) facets.
• The mass activities of stepped Pd nanowires for EOR and EGOR are 3.1 and 2.6 times higher, respectively, than those of Pd nanowires enclosed by (100) facets.
• The synthetic strategy successfully produced bimetallic Pd-Cu nanowires with abundant atomic steps.

Conclusions:

• Abundant atomic steps on electrocatalyst surfaces significantly boost catalytic activity.
• The developed seeded synthesis strategy provides an effective route to obtain mono- and bimetallic nanowires with abundant atomic steps.
• Stepped Pd nanowires show great promise as efficient electrocatalysts for DAFCs.