ausblenden:
Schlagwörter:
Oxygen reduction reaction; Stability; Activity; Core-shell structure; Face-centered tetragonal; FePtCu
Zusammenfassung:
Low-Pt based nanocrystals demonstrate potential as highly active catalysts for the oxygen reduction reaction (ORR), but they suffer from undesirable structural degradation. Therefore, it is highly challenging to optimize their surface and interfacial structures to tune their catalytic properties for both activity and stability. Here core-shell Cu/FePtCu nanoparticles with a face-centered-tetragonal phase are prepared by a facile one-pot polyol method at 320 degrees C. The optimized core-shell Fe45Pt35Cu20 catalyst with Pt-enriched surface exhibits 0.5 A/mgPt mass activity, which is a factor of 4 better than that of commercial Pt/C (0.13 A/mgPt). In addition, the current density of the catalyst drops only 3.0% after 1000 cycles, which is much better than Pt/C (34.2% decay). Using aberration-corrected scanning transmission electron microscopy and atomically resolved elemental mapping, the morphology and structure evolving between the FePtCu alloy and core-shell Cu/FePtCu could clearly be explained. This work demonstrates that an ordered and core-shell FePtCu catalyst is highly promising for ORR and other electrochemical processes.
