Cuprous oxide template synthesis of hollow-cubic Cu2O@PdxRuy nanoparticles for ethanol electrooxidation in alkaline media

Abstract

Surfactant-free and low Pd loading Cu₂O@Pd_xRu_y hollow-cubes were facilely prepared via a galvanic replacement reaction with electrodeposited Cu₂O cubes as sacrificed templates. The morphology and composition of the as-synthesized nanoparticles were characterized, through which the Pd : Ru atomic ratio, metal loading, surface composition and structure of several Cu₂O@Pd_xRu_y nanoparticles were determined. The promotional role of Ru on electrooxidation of ethanol in alkaline media over Cu₂O@Pd_xRu_y was investigated. By comparison, the following electrocatalytic activity order of the catalysts was obtained: Pd/C < Cu₂O@Pd < Cu₂O@Pd₁Ru₃ < Cu₂O@Pd_3.5Ru₁ < Cu₂O@Pd_2.1Ru₁ < Cu₂O@Pd₁Ru_1.6 < Cu₂O@Pd₁Ru₁. Combined with the stability study, the hollow-cubic Cu₂O@Pd₁Ru₁ nanoparticles show superior catalytic activity and stability toward electrooxidation of ethanol in alkaline media compared to the other catalysts studied in this work which is attributed to the appropriate Pd : Ru ratio and the hollow-cubic structure.