Platinum-based intermetallics for oxygen reduction catalysis: from binary to high-entropy

As a key half-reaction in fuel cells, the oxygen reduction reaction (ORR) suffers from sluggish kinetics, and its catalytic efficiency remains a major bottleneck for overall fuel cell performance. In contrast to traditional Pt-based alloy catalysts, which face issues such as transition metal dissolution and poor stability, intermetallics offer stronger structural stability and enhanced interatomic interactions, making them increasingly important in fuel cell catalysis. In recent years, with growing insights into synthesis methods and catalytic mechanisms, intermetallics have evolved from conventional binary systems to ternary and high-entropy systems, demonstrating a clear trend toward compositional diversification. This multi-component innovation provides new opportunities for enhancing fuel cell catalyst performance. In this review, we focus on the application prospects of compositionally diversified intermetallics in ORR electrocatalysis for fuel cells. Beginning with the fundamental mechanism of the ORR, we highlight the advantages of intermetallics in this reaction. We then provide a systematic overview of recent progress in binary, ternary and high-entropy intermetallic catalysts for the ORR electrocatalysis. Finally, we discuss future research directions based on current developments in this field.