Surface-Decorated High-Entropy Alloy Catalysts with Significantly Boosted Activity and Stability

摘要

High-entropy alloy (HEA) nanoparticles are emerging catalytic materials andare particularly attractive for multi-step reactions due to their diverse activesites and multielement tunability. However, their design and optimizationoften involve lengthy efforts due to the vast multielement space and unidentifiedactive sites. Herein, surface decoration of HEA nanoparticles todrastically improve the overall activity, stability, and reduce cost is reported. Atwo-step process is employed to first synthesize non-noble HEA (FeCoNiSn)nanoparticles and then are surface alloyed with Pd (main active site), denotedas NHEA@NHEA-Pd. As a demonstration in the ethanol oxidation reaction,a high mass activity of 7.34 A mg~（?1）Pd and superior stability (>91.8% retentionafter 2000 cycles) in NHEA@NHEA-Pd are achieved, substantiallyoutperforming traditional HEA, binary M@M-Pd (M = Sn, Fe, Co, Ni), andcommercial Pd/C. In situ spectroscopy reveals that NHEA@NHEA-Pd cancatalytically produce and oxidize CO at 200 mV lower thanSn@Sn-Pd, suggesting enhanced activity in NHEA@NHEA-Pd owing to Pd'sunique high-entropy coordination environment. This work provides a noveldesign of HEA catalysts by combining surface decoration (exposing moreactive sites) and high-entropy coordination (enhancing intrinsic activity andstructural stability) to boost catalysts’ activity and durability.