Direct growth of ultrasmall bimetallic AuPd nanoparticles supported on nitrided carbon towards ethanol electrooxidation

作者：Yang, Yue; Jin, Lei; Liu, Ben; Kerns, Peter; He, Jie^*

来源：Electrochimica Acta, 2018, 269: 441-451.

DOI：10.1016/j.electacta.2018.03.017

• Bimetallic nanoparticles
• Ultrasmall metal nanocatalysts
• Surface ligands
• Nitrided carbon
• Ethanol electrooxidation

Bimetallic nanoparticles (NPs) show interesting synergy to enhance the activity and durability in electrocatalytic alcohol oxidation compared to single-component metal NPs. The synthesis of bimetallic NPs often carried out in solution brings challenges in separating, loading and dispersing these NPs on conductive carbon supports. We herein report the direct growth of well-defined AuPd bimetallic NPs in the size range of 2-5 nm on nitrided carbon support. Our method is based on a seed-mediated growth method using Au seeds (1.8 +/- 0.3 nm) supported on nitrided carbon. We show that the sizes and surface compositions of bimetallic NPs are precisely controllable. The resultant core-shell AuPd bimetallic NPs are thermally stable and they can be converted to alloyed AuPd NPs when subjected to thermal activation at 250 degrees C for 1 h. The chemical compositions of the AuPd alloyed NPs have been investigated by combining electron microscopy dispersive X-ray analysis, X-ray photoelectron spectroscopy and surface oxygen desorption using electrochemical reduction of catalysts. The catalytic activity, stability, poisoning tolerance and charge transfer resistance of AuPd alloyed NPs for the ethanol electrooxidation are largely enhanced compared to single-component NPs. Au0.45Pd0.55-5 nm exhibited the superior specific activity of 1.11 mA/cm(2) and mass activity of >0.4 A/mg(metal) toward ethanol oxidation, approximately 5 times more active than commercial Pd/C. We expect that this synthetic method will be of interest to prepare metallic electrocatalysts having defined nanostructures and compositions directly on conductive carbon for applications in fuel cells and batteries.

• 出版日期2018-4-10
• 单位南京理工大学