Khanal Subarna, Casillas Gilberto, Velazquez-Salazar J Jesus, Ponce Arturo, Jose-Yacaman Miguel
Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249.
J Phys Chem C Nanomater Interfaces. 2012 Nov 8;116(44):23596-23602. doi: 10.1021/jp3092418. Epub 2012 Oct 19.
Bimetallic nanoparticles present different properties than their monometallic counterparts, opening a wide range of possibilities for different applications. PtPd nanoparticles have raised interest for their many applications in fuel cells, ethanol and methanol oxidation reactions, hydrogen storage, etc. However, the cost of Pt makes it unpractical to use in big quantities; therefore, one of the big challenges is to synthesize very small catalysts in order to maximize the efficiency in their use. In this work, we synthesized polyhedral PtPd core-shell nanoparticles under 20 nm and characterized them by Cs-corrected scanning transmission electron microscopy. This technique allowed us to probe the structure at the atomic level of these nanoparticles revealing new structural information. We determined the structure of the three main polyhedral morphologies obtained in the synthesis: octahedral, decahedral and triangular plates. Decahedral PtPd core-shell nanoparticles are novel morphologies for this system. Morphology and defects present in the nanoparticles are shown and discussed.
双金属纳米颗粒具有与单金属对应物不同的性质，为不同应用开辟了广泛的可能性。铂钯纳米颗粒因其在燃料电池、乙醇和甲醇氧化反应、储氢等方面的众多应用而引起了人们的兴趣。然而，铂的成本使得大量使用它不切实际；因此，一个重大挑战是合成非常小的催化剂，以最大限度地提高其使用效率。在这项工作中，我们合成了尺寸小于20纳米的多面体铂钯核壳纳米颗粒，并用经校正的扫描透射电子显微镜对其进行了表征。这项技术使我们能够在原子水平上探测这些纳米颗粒的结构，揭示新的结构信息。我们确定了合成中获得的三种主要多面体形态的结构：八面体、十面体和三角形板。十面体铂钯核壳纳米颗粒是该体系的新型形态。展示并讨论了纳米颗粒中存在的形态和缺陷。
