A Novel Approach for the in Situ Synthesis of Pt–Pd Nanoalloys Supported on Fe₃O₄@C Core–Shell Nanoparticles with Enhanced Catalytic Activity for Reduction Reactions

A facile two-step synthesis method has been developed for the synthesis of highly active and well-defined Pt-Pd nanoalloys supported on the surface of Fe3O4@C colloidal nanoparticles. The nanoalloys were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy (STEM) with line scanning of energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy. The nanoalloys exhibit remarkable catalytic activity toward reduction of 4-nitrophenol to 4-aminophenol by NaBH4. Furthermore, the catalytic activity of the supported nanoalloys could be further optimized by tuning the composition of the supported nanoalloys, and the optimized catalytic activity is obtained with a normalized rate constant of about 12.03 nmol(-1) s(-1) when the atomic ratio of Pd to Pt is tuned to 2.07:1, which is advancing among the Pd-based nanocatalysts reported in the recent years.