Facile synthesis of Pt₅La nanoalloys as the enhanced eletrocatalysts for oxygen reduction reaction and methanol oxidation reaction

Platinum-rare earth metal (Pt-RE) nanoalloys are the most promising candidates for fuel cells because of their superior activity and stability for oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). However, the preparation of Pt-RE nanoalloys with chemical method is still challenge due to their huge standard reduction potential differences and the oxophilicity of the latter. Herein, this work provides a novel and facile strategy for the chemical synthesis of Pt5La nanoalloys to apply in both ORR and MOR. Pt5La nanoalloys are synthesized by co-reduction of Pt²⁺ and La³⁺ in LaCl₃ and H₂PtCl₆ solution containing carbon powder and C₂H₄N₄ by first heating at 550 °C for 2 h under N₂, and then heating to 700 °C under H₂/Ar for 2 h. The as-synthesized Pt₅La nanoalloys present a high alloying degree at 700°C, with the average particle size of 7.8 nm. The results indicate Pt₅La nanoalloys lead to a significant enhancement in ORR and MOR performances related to the commercial JM-Pt/C catalyst.