Mesoporous High‐Entropy Alloys With Diverse Compositions via a Versatile Kinetic‐Controlled Co‐Growth Approach

ABSTRACT Mesoporous high‐entropy alloys (MHEAs) have attracted great scientific interest owing to their highly accessible pore structures and multicomponent synergistic effects. However, the controlled synthesis of MHEAs with tunable compositions, high mix configurational entropy (ΔSmix), well‐defined mesoporous frameworks, and regulated pore sizes remains highly challenging. Herein, we report a versatile kinetic‐controlled co‐growth approach for the synthesis of MHEAs. The strategy is readily extendable to a family of compositions, including PtPdRhAgCu, PtPdRhAgRu, PtPdRhAgFe, PtPdRhAgMo, PtPdRhAgNi, and PtPdRhAgGd. The typically obtained PtPdRhAgCu MHEAs possess a ΔSmix of 1.600 R, nearly approaching the theoretical maximum of 1.609 R, and exhibit uniform spherical morphology (∼58 nm) with well‐ordered mesopores (∼11 nm). The mesoporous diameters of the PtPdRhAgCu MHEAs are adjusted from 5.5 to 8.3 and 11.0 nm by employing different types of triblock copolymer. As a proof of concept, PtPdRhAgCu MHEAs with ∼11 nm mesopores exhibit markedly enhanced specific activity and peroxidase‐like catalytic performance compared with their non‐mesoporous and small‐pore (5.5 nm) counterparts.