Palladium-loaded core-shell nanospindle as potential alternative electrocatalyst for oxygen reduction reaction

Highlights: • Well-dispersed Pd Nps on α-Fe₂O₃@SiO₂ nanospindle (PdFS-CSNS) was fabricated. • PdFS-CSNS showed high electrocatalytic activity for oxygen reduction reaction. • PdFS-CSNS was obtained high stability, durability, and great methanol tolerance. -- Abstract: A well-dispersed palladium nanoparticle (Pd NP)-loaded α-Fe₂O₃@SiO₂ core-shell nanospindle (PdFS-CSNS) composite is employed as a potential electrocatalyst for the oxygen reduction reaction (ORR). PdFS-CSNS comprised a uniform core-shell (α-Fe₂O₃@SiO₂) nanospindle structure with a core diameter of 80 nm and shell thickness of 15 nm; the nano-sized Pd NPs (2 nm) were loaded by the in situ reduction method. The structural properties and elemental composition of the as-prepared PdFS-CSNS catalyst is characterized by scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, Fourier-transform infrared spectroscopy, N₂ sorption isotherms, and X-ray photoelectron spectroscopy. Compared to commercial Pt_20%@C, the PdFS-CSNS electrocatalyst demonstrated effective ORR electrocatalytic activity via the 4-electron pathway, high stability, and durability, as well as great methanol tolerance. Such intriguing electrocatalytic performance is ascribed to the highly active Pd NP component and effective production of the silica layer in the novel PdFS-CSNS electrocatalyst. The remarkable electrocatalytic activity of PdFS-CSNS will promote further interest in the development of core-shell nanomaterials for other energy and environmental applications.