Three-Dimensional Pd3Pb Nanosheet Assemblies: High-Performance Non-Pt Electrocatalysts for Bifunctional Fuel Cell Reactions

Even though extensive efforts have been devoted to pursue promising electrocatalysts, the design of high-efficiency and low-cost electrocatalysts continues to be a formidable challenge for commercializing electrochemical energy technologies. Herein, we report the successful creation of a class of three-dimensional ordered Pd3Pb nanosheet assemblies (NSAs) via a wet-chemical approach. Such controlled nanostructures with ordered phase and highly open structure exhibit enhanced electrochemical activity and durability for both the anodic methanol oxidation reaction (MOR) and cathodic oxygen reduction reaction (ORR). In particular, the ordered Pd3Pb NSAs show ORR mass and specific activities of 0.697 A mgPd –1 and 0.989 mA cm–2 at 0.90 V versusthe reversible hydrogen electrode (RHE), which are 8.3 (10.9) and 7.5 (6.4) times higher than those of the commercial Pt/C (Pd/C), respectively, making them among the most efficient catalysts ever achieved for Pd-based ORR catalysts to date. In addition, the ordered Pd3Pb NSAs can even sustain at least 20000 potential cycles with limited activity decay and structure change.