Fabrication, microstructure and electrocatalytic property of novel nanoporous palladium composites

Abstract

Nanoporous palladium composites with second phase embeddings can be fabricated through chemical dealloying of a rapidly solidified Al 70Pd 30 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 Al 3Pd and Al 3Pd 2 intermetallic compounds, and the resultant composites comprise the nanoporous palladium matrix dealloyed from Al 3Pd and the undealloyed Al 3Pd 2 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.