Bimetallic PtAu superlattice arrays: Highly electroactive and durable catalyst for oxygen reduction and methanol oxidation reactions

Superlattice arrays, an important type of nanomaterials , have wide applications in catalysis, optic/electronics and energy storage for the synergetic effects determined by both individual metals and collective interactions. Herein, a simple one-pot solvothermal coreduction approach is developed for facile preparation of bimetallic PtAu alloyed superlattice arrays (PtAu SLAs) in oleylamine, with the assistance of urea via hydrogen bonding induced self-assembly. Urea is essential in morphology-controlled process and prevents PtAu nanoparticles from the disordered aggregation. The characterization and formation mechanism of PtAu SLAs are investigated in details. The as-synthesized hybrid nanocrystals exhibit enhanced electrocatalytic performances for oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) in alkaline electrolyte in comparison with commercial Pt-C (50%, wt.%) and Pt black catalysts.