One-step synthesis of AuPd alloy nanoparticles on graphene as a stable catalyst for ethanol electro-oxidation

• AuPd alloy NPs supported on graphene were synthesized via one-step sputtering deposition.
• Highest activity of AuPd(1:3) NPs for ethanol electro-oxidation in alkaline media was confirmed.
• Synergistic effect between Au and Pd promotes the anti-poisoning performance.
• AuPd(1:3) alloy NPs show extraordinarily durability after 500 cyclic voltammograms.

Room-temperature-ionic-liquid-assisted sputtering with an alloy target is utilized to synthesize the graphene-supported AuPd alloy nanoparticles, whose Au-to-Pd ratio can be well controlled. The preparation process is one-step, free of additives and stabilizers. For direct electro-oxidation of ethanol in alkaline media, the supported AuPd alloy nanoparticles show much higher catalytic activity compared with a commercial Pd/C catalyst and the monometallic counterpart. The optimal Au-to-Pd ratio is 1:3, and the nanocatalyst of AuPd (1:3) possesses high stability and durability. After 500 cyclic voltammetry test cycles, the anodic peak current density for ethanol electro-oxidation still remains about 91% of the initial one. Furthermore, by quantitatively analyzing the relative reactivity retention, the alloy nanoparticle catalysts with graphene as the support show much higher anti-poisoning performance than the corresponding monometallic catalysts with active C as the support.