Size-specific catalytic activity of platinum clusters enhances oxygen reduction reactions.
Size-specific catalytic activity of platinum clusters enhances oxygen reduction reactions.
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DOI：
10.1038/nchem.288
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发表时间：
2009-08
期刊：
影响因子：
21.8
通讯作者：
Kimihisa Yamamoto;T. Imaoka;W. Chun;Osamu Enoki;H. Katoh;Masahiro Takenaga;Atsunori Sonoi
中科院分区：
文献类型：
--
作者：
Kimihisa Yamamoto;T. Imaoka;W. Chun;Osamu Enoki;H. Katoh;Masahiro Takenaga;Atsunori Sonoi
目前认为碳载体上直径为2-5 nm的胶体铂纳米颗粒是氧还原反应的最佳催化剂。然而，颗粒尺寸受到用于合成小铂颗粒的常规制备方法的限制;超小纳米颗粒的固有活性尚未被揭示。我们提出了一个实用的合成超细亚纳米铂簇使用球形高分子模板分子的分子量和结构没有混乱。模板，苯基甲亚胺树枝状聚合物，提供控制的数量的金属配合物在一个组件通过逐步络合，使配合物积累在离散的纳米笼。随后将Pt（IV）氯化物还原为Pt（0）导致形成由限定数量的原子组成的铂簇。由于颗粒尺寸非常小，簇合物对氧分子的四电子还原表现出非常高的催化活性。
Colloidal platinum nanoparticles with diameters of 2–5 nm on carbon supports are currently regarded as the best catalysts for the oxygen reduction reaction. However, the particle size is limited by the conventional preparation methods that are used to synthesize small platinum particles; the inherent activity of ultrasmall nanoparticles has not yet been revealed. We present a practical synthesis for ultrafine subnanometre platinum clusters using a spherical macromolecular template with no disorder in molecular weight or structure. The template, a phenylazomethine dendrimer, offers control of the number of metal complexes in an assembly through stepwise complexation, allowing the complexes to accumulate in discrete nano-cages. Subsequent reduction of Pt(IV) chloride to Pt(0) results in the formation of platinum clusters composed of a defined number of atoms. As a result of exceptionally small particle size, the clusters exhibit very high catalytic activity for the four-electron reduction of oxygen molecules.