Asymmetric Au/(PdAg alloy) nano-allium giganteums for their enhanced electrocatalytic performances to ethanol oxidation reaction

Abstract

Morphology control is an effective strategy to enhance the electrocatalytic of metal nanocrystals in fuel cells. Herein, we synthesized Au/(PdAg alloy) nano-allium giganteums with a very high purity of almost 99% using an easy operation synthetic method. The Au/(PdAg alloy) nano-allium giganteum, in which PdAg alloyed nanoparticles only located on one end of the Au NR, was successfully obtained through a Ostwald ripening process which is significantly promoted by the addition of Br− ions. Due to the alloyed feature and the special morphology, we also utilized the Au/(PdAg alloy) nanostructures as electrocatalysts toward the ethanol oxidation reaction in alkaline and benchmarked to the commercial Pd/C nanoparticles. The specific activity of Au/(PdAg alloy) nano-allium giganteum is 2.1 mA cm−2, which is 3.2 times of the commercial Pd/C (0.65 mA cm−2). The Au/(PdAg alloy) electrocatalysts also have a higher mass activity of 0.73 A mg−1Pd, which is 2.0 times that of commercial Pd/C (0.36 A mg−1Pd). Furthermore, the durability is also highly improved due to the presence of the exposed Au NR. We thus believed that the Au/(PdAg alloy) nano-allium giganteums can become an attractive catalyst in fuel cells.