Platinum-Based Intermetallic Compounds: Synthesis Strategies, Structural Ordering, and Oxygen Reduction Electrocatalysis.

Platinum-based intermetallic compounds have emerged as promising electrocatalysts for the oxygen reduction reaction (ORR), as their ordered atomic arrangements enable effective modulation of electronic structure while offering improved durability compared with conventional Pt alloys. Atomic ordering improves structural stability and modulates ligand and strain effects, facilitating optimized adsorption of oxygen-containing intermediates and improved ORR kinetics. This review summarizes recent advances in the synthesis of Pt-based intermetallic nanocrystals, covering low- and high-temperature strategies, including support-assisted approaches, vacancy engineering, solvothermal synthesis, and solution-phase methods. The relationship between composition, electronic structure, crystal structure, and ORR performance is discussed, with emphasis on the roles of atomic ordering, compositional regulation, and catalyst-support interactions. Finally, current limitations and future directions for the rational design of highly active and durable Pt-based intermetallic electrocatalysts are discussed. This review provides insights into the design and development of next-generation catalysts for fuel cells and sustainable energy conversion technologies.