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The tailored design of tri-metallic Pt-based porous nanodendrites (PNDs) is crucial for green energy production technologies, ascribed to their fancy features, great surface areas, accessible active sites, and stability against aggregation. However, their aqueous-phase one-step synthesis at room temperature remains a daunting challenge. Herein, we present a facile, green, and template-free approach for the one-step synthesis of PtPdCu PNDs by ultrasonication of an aqueous solution of metal salts and Pluronic F127 at 25 ℃, based on natural isolation among nucleation and growth step driven by the disparate reduction kinetics of the metals and acoustic cavitation mechanism of ultrasonic waves. The resultant PtPdCu PNDs formed in a spatial nanodendritic shape with a dense array of branches, open corners, interconnected pores, high surface area (46.9 m2/g), and high Cu content (21 %). The methanol oxidation reaction (MOR) mass activity of PtPdCu PNDs (3.66 mA/µgPt) is 1.45, 2.73, and 2.83 times higher than those of PtPd PNDs, PtCu PNDs, and commercial Pt/C, respectively based on equivalent Pt mass, which is superior to previous PtPdCu catalysts reported elsewhere, besides a superior durability and CO-poisoning tolerance. This study may pave the way for the controlled fabrication of ternary Pt-based PNDs for various electrocatalytic applications.

Binary PdM-based nanocrystals are efficient electrocatalysts for a wide range of renewable and green fuel cell applications; however, their poisoning by CO is a great barrier for commercialization, so it is pivotal to solve this issue. Herein, we fabricated support-free PdM alloys (M = Fe, Co, and Ni) by a prompt one-step aqueous-solution co-reduction with sodium borohydride driven by the coalescence growth mechanism. This forms support-free PdM porous foam-like nanostructures with well-defined compositions from the ICP-OES analysis and clean surface without any hazardous chemicals or multiple reaction steps. The as-prepared PdM foam-like nanostructures were demonstrated for carbon monoxide oxidation (COOxid) electrocatalysis at varied electrolyte pH compared with commercial Pd/C catalyst. The foam-like PdFe nanocrystals achieved an excellent electrochemical COOxid activity that was at least 2.18-times of PdCo, 4.35-times of PdNi, and 1.56-times of Pd/C in both alkaline (KOH) and acidic (HClO4) electrolytes, but PdCo was the best in neutral (NaHCO3) medium. The superior activity of PdM is due to the strain and alloying effect, which promoted the superb CO oxidation durability for 1000 cycles than Pd/C catalyst. This study demonstrated the superiority of support-free bimetallic PdM alloys than Pd/C catalyst in all electrolytes, which may open new gates for understanding CO-poisoning in alcohol-based fuel cells.