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The poisoning of undesired intermediates or impurities greatly hinders the catalytic performances of noble metal‐based catalysts. Herein, high‐entropy intermetallics i‐(PtPdIrRu)2FeCu (HEI) are constructed to inhibit the strongly adsorbed carbon monoxide intermediates (CO*) during the formic acid oxidation reaction. As probed by multiple‐scaled structural characterizations, HEI nanoparticles are featured with partially negative Pt oxidation states, diluted Pt/Pd/Ir/Ru atomic sites and ultrasmall average size less than 2 nm. Benefiting from the optimized structures, HEI nanoparticles deliver more than 10 times promotion in intrinsic activity than that of pure Pt, and well‐enhanced mass activity/durability than that of ternary i‐Pt2FeCu intermetallics counterpart. In situ infrared spectroscopy manifests that both bridge and top CO* are favored on pure Pt but limited on HEI. Further theoretical elaboration indicates that HEI displayed a much weaker binding of CO* on Pt sites and sluggish diffusion of CO* among different sites, in contrast to pure Pt that CO* bound more strongly and was easy to diffuse on larger Pt atomic ensembles. This work verifies that HEIs are promising catalysts via integrating the merits of intermetallics and high‐entropy alloys. [ABSTRACT FROM AUTHOR]

The synthesis of Pd nanocrystals of controlled size and morphology has drawn enormous interest due to their catalytic activity. We report a new and efficient strategy for the one-step synthesis of monodispersed Pd nanocubes with ethylenediamine tetramethylene phosphonate (EDTMP) as a complex-forming and capping agent. The morphology, structure, and growth mechanism of the Pd nanocubes were fully characterized via selected area electron diffraction (SAED), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). It was found that the morphology of the Pd nanocrystals in the proposed EDTMP-PdCl system could be changed from octahedrons to nanocubes simply by adjusting the amount of iodide used during synthesis. After UV/ozone and electrochemical cleaning, the as-prepared Pd nanocubes demonstrated excellent electrocatalytic activity and stability during formic acid oxidation, owing to their abundant {100} facets and small particle size. [ABSTRACT FROM AUTHOR]