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Abstract:Developing low-Pt catalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cell (PEMFC) remains a significant challenge due to the stringent demands on both high power density and long-term durability. Guided by theoretical calculations, we identify Co-NC as the most prospective transition metal and nitrogen-doped carbon (M-NC) support. Co-NC exhibits the strongest interaction with Pt, lowering the energy level of the Pt d-band, which enhances both stability and activity. Furthermore, the ordered Pt3Co/Co-NC catalyst achieves a mass activity (MA) of 0.76 A mg P t-1 at 0.9 V iR-free vs. RHE, with a loss of only 12 mV in half- wave potential after 30 k cycles of accelerated degradation test (ADT). The membrane electrode assembly (MEA) composed of Pt3Co/Co-NC cathode delivers excellent performance exceeding the DOE 2025 target, with MA is 0.66 A mg P t-1 at a cell voltage of 0.9 V, and 74.8 % of the initial performance was retained after 30 k ADT cycles. Experimental and theoretical investigations, combining in situ surface-enhanced infrared spectroscopy reveal that the *OOH intermediates are stabilized at the Co-NC active sites, while *OH adsorption on the Pt sites in Pt3Co is weakened, leading to optimal adsorption of oxygen-containing intermediates on dual active sites, and effectively addresses the limitations associated with single active sites. This work sheds light on the synergistic effect of the different M-NC and Pt nanoparticles, paving the way for designing highly active and stable catalysts for PEMFC applications.

Volume:503

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Translation or Not:no