ABSTRACT The development of highly efficient and durable Pt‐based oxygen reduction reaction (ORR) catalysts is paramount for the widespread adoption of proton exchange membrane fuel cells (PEMFCs). Herein, we present a novel Y‐doped PtFeNi medium‐entropy alloy catalyst, PtFeNiY 8 (PFNY 8 , 8% Y doping), synthesized via a simple one‐pot method, achieving preferential exposure of the highly active (111) crystal facet. Systematic experiments and density functional theory calculations demonstrate that Y doping lowers surface energy to promote the formation of the (111) crystal facet, with an optimal doping level of 8% achieving the most stable electronic structure and the most favorable d ‐band center. The PFNY 8 /C catalyst demonstrates outstanding ORR performance, with a half‐wave potential ( E 1/2 ) of 0.93 V, mass activity (MA) of 3.00 A mg −1 Pt , and excellent durability (after 80,000 ADT cycles, the E 1/2 decreases by only 11 mV, and the MA retention is 73.4%). Furthermore, in PEMFCs, PFNY 8 /C demonstrates a peak power density of 1.75 W cm −2 under H 2 /O 2 conditions, outperforming commercial Pt/C. This study offers valuable insights into the role of Y doping in tailoring nanoparticle morphology and facet exposure, presenting a new strategy for designing high‐performance Pt‐based catalysts for next‐generation PEMFCs.
Gao et al. (Mon,) studied this question.