Fabrication, microstructure and electrocatalytic property of novel nanoporous palladium composites

Nanoporous palladium composites with second phase embeddings can be fabricated through chemical dealloying of a rapidly solidified Al70Pd30 alloy in alkaline or acidic solutions under free corrosion conditions. The microstructure of the precursor alloy and as-dealloyed nanoporous composites was characterized using X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. The experimental results show that the precursor alloy is composed of Al3Pd and Al3Pd2 intermetallic compounds, and the resultant composites comprise the nanoporous palladium matrix dealloyed from Al3Pd and the undealloyed Al3Pd2 embeddings. Moreover, the length scale of ligaments/channels in the nanoporous matrix can be adjusted from 3–6 nm to 15–25 nm by simply changing the dealloying solution. The electrochemical experiments demonstrate that these nanoporous Pd composites have high electrochemical active surface areas and exhibit remarkable electrocatalytic activities towards methanol and ethanol oxidation in alkaline media. These novel nanoporous Pd composites will find potential applications in fields of direct alcohol fuel cells, catalysis, sensing, actuation, and especially load-related areas.

Research highlights▶ Nanoporous palladium composites can be fabricated through dealloying Al–Pd alloys. ▶ The ligaments/channels size can be tuned by changing dealloying solutions. ▶ Nanoporous Pd composites show superior activity towards alcohol electro-oxidation.