19 research outputs found

    Ethanol Electrooxidation Catalyzed by Tungsten Core@Palladium Shell Nanoparticles

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    Bimetallic nanostructures represent effective electrocatalysts toward a number of important reactions. In the present study, carbon-supported palladium–tungsten alloy nanoparticles with a quasi-tungsten core@palladium shell structure (W@Pd/C) were synthesized by a galvanic replacement reaction of amorphous tungsten nanoparticles with Pd­(II) at different temperatures (0, 25, and 50 °C), and exhibited apparent electrocatalytic activity toward ethanol oxidation reaction (EOR). When the sample was prepared at 0 °C, large amorphous tungsten nanoparticles were etched off and much smaller W@Pd nanoparticles were formed and dispersed rather evenly on the carbon surface whereas at higher reaction temperatures (25 and 50 °C), the W@Pd nanoparticles became agglomerated. The structures of the obtained samples were characterized by a range of experimental tools, including (scanning) transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical methods. Among the series, the W@Pd/C sample prepared at 0 °C was observed to exhibit the best EOR performance, with a mass activity (9535.5 mA mgPd–1) over three times better than that of commercial Pd/C and markedly enhanced stability

    Curved Porous PdCu Metallene as a High-Efficiency Bifunctional Electrocatalyst for Oxygen Reduction and Formic Acid Oxidation

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    Designing high-efficiency and newly developed Pd-based bifunctional catalytic materials still faces tremendous challenges for oxygen reduction reaction (ORR) and formic acid oxidation reaction (FAO). Metallene materials with unique structural features are considered strong candidates for enhancing the catalytic performance. In this work, we synthesized copper-doped two-dimensional curved porous Pd metallene nanomaterials via a simplistic one-pot solvothermal method. The updated catalysts served as sturdy bifunctional electrocatalysts for cathodal ORR and anodic FAO. In particular, the developed PdCu metallene exhibits excellent half-wave potential (0.943 V vs RHE) and mass activity (MA) (1.227 A mgPt–1) in alkaline solutions, which are 1.09 and 6.26 times higher than those of commercial Pt/C, respectively, indicating that the nanomaterials have abundant active sites, displaying surpassing catalytic performance for oxygen reduction. Furthermore, in an acidic formic acid electrolyte, PdCu metallene exhibits prominent MA with a value of 0.905 A mgPd–1, which is 2.76 times that of commercial Pd/C. The remarkable bifunctional catalytic performance of metallene materials can be attributed to the special structure and electronic effects. This work shows that metallene materials with curved and porous properties provide a scientific idea for the development and design of efficient and steady electrocatalysts
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