Tellurium–Nitrogen–Carbon Support Boosting Platinum Catalysis in High‐Efficiency Proton Exchange Membrane Fuel Cells

Abstract Enhancing the energy conversion efficiency of fuel cells necessitates optimization of oxygen reduction reaction (ORR) under high‐voltage conditions through improved Pt catalysis. This study introduces an electrocatalyst that uniformly anchors a high loading (40 wt%) of small Pt nanoparticles (3.2 nm) on a novel support: tellurium and nitrogen co‐mediated graphitized mesoporous carbon (Te–N–GMC). The strong metal–support interactions arise from Pt─Te and Pt─N bonds. Density functional theory (DFT) calculations and operando X‐ray absorption spectroscopy reveal that Te–N co‐mediation enhances the high‐voltage oxidation resistance of Pt via electron reverse transfer from the Te–N–GMC support to Pt. Consequently, the Pt valence state in Pt/Te–N–GMC increases by only +0.085 from open‐circuit potential to 1.5 V, resulting in exceptional durability over 100 000 high‐voltage cycles (1–1.5 V) with negligible morphological aggregation. Moreover, the Te–N–GMC support effectively lowers the energy barrier of the rate‐determining step, enabling Pt/Te–N–GMC to achieve outstanding activity (0.7 V at 1.26 A cm −2 under H 2 –air conditions). This translates to an 18.6% increase in electrical efficiency compared with commercial Pt/C at the same output power density. These findings demonstrate the potential of Te–N–GMC as a robust cocatalyst for high‐voltage ORR and highlight a promising strategy for enhancing Pt catalysis for high‐efficiency fuel cells.