Porous octahedral PdCu nanocages as highly efficient electrocatalysts for the methanol oxidation reaction

Abstract

Porous octahedral PdCu alloy nanocages are prepared by templating against Cu₂O together with the disproportionation and displacement reactions at room temperature. Through tuning the molar ratios of the Pd/Cu precursors (PdCl₄²⁻/Cu₂O), the morphology and the electrocatalysis of the octahedral PdCu nanocages can be controlled. The PdCu-5 (Pd/Cu precursor ratio of 1 : 5) nanocages exhibit superior electrocatalytic activity (1090 mA mg_Pd⁻¹) towards the methanol oxidation reaction, 2.9 times higher than that of the commercial Pd/C catalyst, with remarkable durability. The combined characterization by SEM, TEM, XRD and XPS demonstrated that the excellent performance and durability of the PdCu-5 nanocages can be ascribed to their excellent hollow and porous structures as well as the electronic effect between the noble metal Pd and the cheap metal Cu. Herein, this kind of nanomaterial with novel cage-like structures is a promising catalyst for direct methanol fuel cells (DMFCs).