The development of highly efficient and stable Pd-based catalysts is crucial to improve their sluggish oxygen reduction reaction (ORR) kinetics in acid media. To improve ORR activity and utilization efficiency of Pd, an ideal catalyst should have ORR-favorable chemical environment, optimized geometric structure, and long periods of operation. In this work, we first synthesize a novel trimetallic Au@PdPb core-shell catalyst consisting of PdPb alloy nano-layers grown on the surface of ultrathin Au nanowires (NWs) by a two-step water-bath method. The Au@PdPb NWs have the merits of anisotropic one-dimensional nanostructure, high utilization efficiency of Pd atoms and doping of Pb atoms. Because of the structural and multiple compositional advantages, Au@PdPb NWs exhibit remarkably enhanced ORR activity with a high half-wave potential (0.827 V), much better than those of commercial Pd black (0.788 V) and bimetallic Au@Pd NWs (0.803 V). Moreover, Au@PdPb NWs display better electrocatalytic stability for the ORR than those of Pd black and Au@Pd NWs. This study demonstrates the validity of our approach for deriving highly ORR-active Pd-based catalysts by modifying their structure and composition.

高效稳定的Pd基催化剂的开发对于改善其在酸性介质中缓慢的氧还原反应（ORR）动力学至关重要。为了提高ORR活性和Pd的利用效率，理想的催化剂应具有对ORR有利的化学环境，优化的几何结构以及较长的操作时间。在这项工作中，我们首先通过两步水浴法合成了一种新型的三金属Au @ PdPb核壳催化剂，该催化剂由生长在超薄金纳米线（NWs）表面上的PdPb合金纳米层组成。Au @ PdPb NWs具有各向异性的一维纳米结构，Pd原子的高利用率和Pb原子掺杂的优点。由于结构和多重组成上的优势，Au @ PdPb NW表现出显着增强的ORR活性，具有高的半波电势（0.827 V），比商用Pd黑（0.788 V）和双金属Au @ Pd NW（0.803 V）更好。此外，Au @ PdPb NWs对ORR的电催化稳定性优于Pd黑色和Au @ Pd NWs。这项研究证明了我们通过改变结构和组成来获得高ORR活性的Pd基催化剂的方法的有效性。