Park, Yeji Seok, Jun Ho Park, Jae-Hyun Kim, Doyeop Cho, Seong Chan Kim, Minsu Jeong, Yujin Kim, Taekyoung Baik, Hionsuck Lee, Sang Uck Yoo, Sung Jong Lee, Kwangyeol 2026-02-04T05:30:49Z 2026-02-04T05:30:49Z 2026-02-02 2026-02 0935-9648 https://pubs.kist.re.kr/handle/201004/154190 The sluggish kinetics and limited durability of the oxygen reduction reaction (ORR) at the cathode remain a major barrier to the widespread deployment of proton exchange membrane fuel cells (PEMFCs). Here, we introduce a low-temperature interfacial engineering strategy to construct ternary L12-ordered Pt3(Co,Mn)1 intermetallic nanoparticles. A conformal MnO shell on Pt3Co1 cores not only suppresses particle coalescence but also undergoes redox activation to generate interfacial oxygen vacancies that initiate the disorder-to-order transition. During thermal activation, these vacancies mediate Co-Mn atomic exchange across the core@shell interface, forming interfacial Co-O and intralattice Pt-Mn bonds that cooperatively stabilize the ordered framework. This oxygen-vacancy-driven interfacial evolution reconfigures the Pt electronic structure, downshifting the d-band center, enriching electron density at Pt active sites, and optimizing oxygen-intermediate adsorption. The resulting catalyst exhibits high intrinsic ORR activity and outstanding durability over extended accelerated cycling. When implemented into practical membrane-electrode assemblies, it surpasses the U.S. Department of Energy (DOE) 2025 PEMFC benchmarks for both rated power density and durability, demonstrating its promise for real-world fuel cell applications. More broadly, this work establishes redox-active, confinement-mediated interfacial engineering as a general paradigm for directing atomic ordering and electronic structure in complex multimetallic electrocatalysts. English WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Tailoring Interfacial Oxygen Vacancy-Mediated Ordering in Ternary Pt3(Co,Mn)1 Intermetallic Nanoparticles for Enhanced Oxygen Reduction Reaction Article 10.1002/adma.202521036 1 Advanced Materials, v.38, no.11 Advanced Materials 38 11 N scie scopus 2-s2.0-105026769411 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics Article; Early Access ALLOY NANOPARTICLES PHOTOCATALYTIC PERFORMANCE CARBON CORROSION AT-PT CATALYSTS SEGREGATION ELECTROCATALYSTS EVOLUTION ELECTRODE FE interfacial engineering intermetallic compound oxygen reduction reaction (ORR) oxygen vacancy proton exchange membrane fuel cell (PEMFC)