Highly Efficient Oxygen Reduction Reaction Electro-Catalyzed by Ultrasmall Pt@Mn Core-Shell Nanoparticles.

Electro-catalyzed oxygen reduction reaction (ORR), as the positive electrode reaction, is significant to the performance of fuel cells and metal-air batteries. Toward ORR, ultra-small Pt@Mn core-shell nanoparticles catalysts supported on Ketjen black are synthesized by a simple one-pot hydrothermal method. TEM results show that the Pt@Mn/C nanoparticles with an average size of 3∼4 nm are uniformly distributed on the carbon surface. ORR performance of the electrocatalysts shows that Pt@Mn/C exhibits better oxygen reduction activity than Pt/C (20 wt %) in a KOH solution. Methanol tolerance ability as well as the durability of the Pt@Mn/C is also superior to the performance of Pt/C, suggesting an enhanced ORR activity upon the introduction of Mn.