Enhanced electro-catalytic performance of Pd-based hierarchical nanoporous structures fabricated by micropatterning and dealloying of Pd-Ni-P metallic glass.

ABSTRACT

Pd-based catalysts are of significance for their application in direct alcohol fuel cells, due to the superior electro-catalytic performance and CO poisoning resistance. In this work, using Pd32Ni48P20 metallic glassy ribbon as precursor, micro/nano hierarchical nanoporous structure was constructed by the hybrid approach of thermal plastic micropatterning and subsequently electrochemical dealloying at 0.88 V for 120 min in 0.5 M H2SO4 and 0.5 M H3PO4. This hierarchical structure was composed of the periodical micro-rods and nanoporous structure, where the chemical constituent was 80.33 at% Pd, 4.87 at% Ni, 4.96 at% P, and 9.84 at% O. The nanoporous structures showed an enhanced methanol electro-oxidation performance in alkaline medium, owing to their enlarged specific surface area. Compared to single nanoporous structure, the hierarchical nanoporous structure exhibited much better electro-catalysis, mainly attributed to the large surface area and high mass transfer efficiency, indicating a promising perspective for the application in alkaline direct alcohol fuel cells.