Dual-Site Engineering Enables Strong Metal–Support Electronic Interactions for Superior Pt3– x Ir x Co/bd-NMC Intermetallic Fuel Cell Composite Catalysts

Abstract Rational design of Pt-based intermetallic composites represents a key strategy to regulate the oxygen reduction reaction (ORR) kinetics, durability, and cost effectively in proton exchange membrane fuel cells (PEMFCs). Herein, we develop a dual-site engineering strategy to prepare a Pt2.8Ir0.2Co/bd-NMC (Ir and Co co-doped nitrogen-doped carbon denoted as bd-NMC) composite catalyst on ZIF-8-derived NMC, which constructs strong metal–support electronic interactions to simultaneously enhance ORR kinetic activity/stability and cost-effectiveness. Comprehensive characterizations reveal that Ir/Co in the Pt2.8Ir0.2Co and Ir/Co–N4–C sites synergistically donate electrons to Pt, downshift the Pt d-band center, and strengthen nanoparticle anchoring, leading to superior ORR performance. Mass activity of the optimized Pt2.8Ir0.2Co/bd-NMC catalyst is 14.55-fold higher than that of commercialPt/C. More importantly, the optimized catalyst exhibits ultralong durability with only a 5 mV decay in half-wave potential after 30,000 accelerated durability test cycles. As the cathodic catalyst in a H2-air PEMFC, the Pt2.8Ir0.2Co/bd-NMC catalyst achieves a current density of 1.49 A cm–2 at 0.6 V, higher than that of Pt3Co/d-NMC (1.26 A cm–2) and commercial Pt/C (0.90 A cm–2) at 0.6 V. This work highlights that dual-site (dual-single-atom-site and Pt-based TIMNs) engineering serves as an effective and sustainable approach to enhance the performance of Pt-based composite catalysts.