Direct synthesis of L1₀-FePt nanoparticles from single-source bimetallic complex and their electrocatalytic applications in oxygen reduction and hydrogen evolution reactions

L1₀-FePt nanoparticles (NPs) with high chemical ordering represent effective electrocatalysts to reduce the cost and enhance their catalytic performance in fuel cells. A molecular strategy of preparing highly ordered FePt NPs was used by direct pyrolysis of a Fe, Pt-containing bimetallic complex. The resultant L1₀-FePt NPs had very high crystallinity as reflected by the obvious diffraction patterns, clear lattice fringes and characteristic X-ray diffraction peaks, etc. Besides, the strong ferromagnetism with room temperature coercivity of 27 kOe further confirmed the face-centered tetragonal (fct) phase in good agreement with the ordered nanostructures. The FePt NPs can be used as electrocatalysts to catalyze oxygen reduction reaction (ORR) in an O₂-saturated 0.1 M HClO₄ solution and hydrogen evolution reaction (HER) in the 0.5 M H₂SO₄ electrolyte with much better performance than commercial Pt/C, and showed quite high stability after 10, 000 cycles. The strategy utilizing organometallic precursors to prepare metal alloy NPs was demonstrated to be a reliable approach for improving the catalytic efficiency in fuel cells.