Surfactant-Directed Synthesis of Ternary Nanostructures: Nanocubes, Polyhedrons, Octahedrons, and Nanowires of PtNiFe. Their Shape-Dependent Oxygen Reduction Activity

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• 作者：Shang-Wei Chou ; Jing-Jong Shyue ; Chia-Hua Chien ; Chia-Chun Chen ; Yang-Yuan Chen ; Pi-Tai Chou
• 刊名：Chemistry of Materials
• 出版年：2012
• 出版时间：July 10, 2012
• 年：2012
• 卷：24
• 期：13
• 页码：2527-2533
• 全文大小：472K
• 年卷期：v.24,no.13(July 10, 2012)
• ISSN：1520-5002

文摘

We report a rational method for preparation of ternary alloy (PtNiFe) nanocrystals with various shapes. PtNiFe nanocubes, polyhedrons, and octahedrons are prepared via fine-tuning the alloy compositions and surfactants, so that the crystal facet鈥搒urfactant bindings on the growth seed can be well controlled. Nanowires grow in the cylindrical template built via high concentrations of oleylamine. In the electrocatalysis examination, it appears that the oxygen reduction reaction (ORR) activities of all PtNiFe nanostructures outperform that of commercial Pt catalyst in the electrolyte of HClO₄ or H₂SO₄. In HClO₄, the order of ORR activity is as follows: octahedrons 鈮?nanowires > polyhedrons > nanocubes. PtNiFe nanostructures enclosed by a (111) plane, such as octahedrons and nanowires, give the highest ORR activities. Conversely, in H₂SO₄, the ORR activity of PtNiFe nanocubes enclosed by {100} facets is the highest among these nanostructures. The ORR activity increases in the order of nanowires 鈮?octahedrons < polyhedrons, establishing a shape dependency in the ORR activity, which is valuable upon performing nanocatalysis in fuel cells.

Keywords:

PtNiFe; shape control; nanocube; octahedron; polyhedron; nanowire; oxygen reduction