Integrating PtCo Intermetallic with Highly Graphitized Carbon Toward Durable Oxygen Electroreduction in Proton Exchange Membrane Fuel Cells

Abstract

Exploiting robust and high‐efficiency electrocatalysts for sluggish oxygen reduction reaction (ORR) is essential for proton exchange membrane fuel cells (PEMFCs) toward long‐term operation for practical applications, yet remains challenging. Herein, the ordered PtCo intermetallic is reported with a Pt‐rich shell loaded on a highly graphitized carbon carrier (O‐PtCo@GCoNC) prepared by an impregnation annealing strategy. Systematic X‐ray spectroscopic, operando electrochemical techniques and theoretical calculations reveal that thanks to the synergistic interaction of the core–shell PtCo intermetallic structure with a tailor‐made Pt electronic configuration and highly graphitized carbon, O‐PtCo@GCoNC exhibits significantly enhanced activity and stability toward ORR. Crucially, O‐PtCo@GCoNC delivers a much‐enhanced mass activity of 0.83 A mgPt−1 at 0.9 V versus reversible hydrogen electrode (RHE) in 0.1 m HClO4, which only drops by 26.5% after 70 000 cycles (0.6–1.0 V vs RHE), and 10.8% after 10 000 cycles (1.0–1.5 V vs RHE), apparently overmatching Pt/C (0.19 A mgPt−1, 73.7%, and 63.1%). Moreover, O‐PtCo@GCoNC employed as the cathode catalyst in H2/air PEMFC achieves a superb peak power density (1.04 W cm−2 at 2.06 A cm−2), outperforming that of Pt/C (0.86 W cm−2 at 1.79 A cm−2). The cell voltage loss at 0.8 A cm−2 is 28 mV after 30 000 cycles, outstripping the United States Department of Energy 2025 target.