Heterogeneous Engineering-Induced Electron Enrichment in Carbon Support for High-Stability Proton Exchange Membrane Fuel Cells

The widespread adoption of proton exchange membrane fuel cells (PEMFCs) is significantly hindered by the rapid degradation of oxygen reduction reaction (ORR) catalysts under harsh operational conditions. Here, a CeO_x-integrated heterogeneous carbon support engineering strategy is proposed to stabilize the Co-N₄-C catalyst (Co SAs/CeO_x-NC), achieving simultaneous activity-stability enhancement in PEMFCs. Density functional theory (DFT) calculations reveal that the enhanced binding energy between Co and the carbon support, combined with the reducibility provided by the electron-rich nature of the carbon support, synergistically suppresses Co dissolution and carbon oxidation corrosion. Concurrently, the CeO_x-induce interfacial charge redistribution downshifts the Co d-band center by 0.12 eV, weakening the over-adsorption of oxygenated intermediates and enhancing ORR kinetics. The optimized Co SAs/CeO_x-NC catalyst demonstrates exceptional durability in acidic media (ΔE_1/2 = 8 mV after 5k cycles at high potential of 1.0–1.6 V), outperforming the control Co SAs/NC catalyst (ΔE_1/2 = 30 mV). The Co SAs/CeO_x-NC-based PEMFC achieves outstanding peak power density of 1.04 W cm⁻² and durability (95% voltage retention after 150 h open-circuit conditions test).