Synergistic Electronic Effects in Pt-Based Bifunctional Electrocatalysts through Fe-Co Dual Sites Engineering

The widespread application of Pt-based catalysts in fuel cells is limited by their high cost and insufficient durability for both the oxygen reduction reaction (ORR) and alcohol oxidation reactions (AOR). Herein, we designed a bifunctional catalyst featuring Pt nanoparticles anchored on the nitrogen-doped carbon support engineered with atomically dispersed Fe-N₄ and Co-N₄ dual sites (Pt/FeCoNC) for efficient ORR and AOR. For the acidic ORR, Pt/FeCoNC delivers a half-wave potential of 0.90 V vs RHE, with mass and specific activities 5.6 and 5.1 times higher than commercial Pt/C. Impressively, it retains nearly 60% of its initial mass activity after 30,000 durability cycles, far exceeding Pt/C (∼33% retention). Furthermore, the prepared catalyst demonstrates exceptional AOR activity, with mass activities for methanol and ethanol oxidation over 3 times greater than Pt/C. The prepared catalyst utilizes a strong synergistic interaction between Pt and the bimetallic sites to induce electron delocalization, which downshifts the Pt d-band center. This electronic modulation simultaneously weakens the adsorption of poisoning intermediates and enhances nanoparticle stability. The results establish dual-atom site engineering as a highly effective approach to design durable and active bifunctional catalysts for energy conversion.