Engineering Pt-group high-entropy alloy for electrocatalytic fuel oxidation

High-entropy alloys (HEAs) not only inherit the properties of traditional alloys, but also possess the advantageous merits of lattice distortion, which show promising applications in the field of electrocatalysis. Endowed with the combination of high intrinsic activity of Pt-group metals and inherent characteristics of HEAs, Pt-group HEAs are thus emerging as promising electrocatalysts toward fuel oxidation reactions (FORs). On the basis of rapid development of advanced HEAs and a clear identification of the reaction mechanisms of FORs, this review critically examines the recent advances of Pt-group HEAs used as electrocatalysts for FORs in fuel cells. Started by manifesting the definition and core effects of HEAs, it shows the great advantages over conventional alloys for electrocatalytic FORs. Subsequently, various effective strategies for the synthesis of Pt-group HEAs are also illustrated, followed by a systematic discussion for the applications of HEAs toward FORs and highlighting the underlying structure-activity relationship. Last, we outline the directions for future work in the fabrication of more prominent Pt-group HEAs, which is indispensable for creating high-performing new HEA electrocatalysts.