Role of Ru Oxidation Degree for Catalytic Activity in Bimetallic Pt/Ru Nanoparticles

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• 作者：Huanhuan Wang ; Shuangming Chen ; Changda Wang ; Ke Zhang ; Daobin Liu ; Yasir A. Haleem ; Xusheng Zheng ; Binghui Ge ; Li Song
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：March 31, 2016
• 年：2016
• 卷：120
• 期：12
• 页码：6569-6576
• 全文大小：486K
• ISSN：1932-7455

文摘

Understanding the intrinsic relationship between the catalytic activity of bimetallic nanoparticles and their composition and structure is very critical to further modulate their properties and specific applications in catalysts, clean energy, and other related fields. Here we prepared new bimetallic Pt–Ru nanoparticles with different Pt/Ru molar ratios via a solvothermal method. In combination with X-ray diffraction (XRD), transmission electron microscopy (TEM) coupled with energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and synchrotron X-ray absorption spectroscopy (XAS) techniques, we systematically investigated the dependence of the methanol electro-oxidation activity from the obtained Pt/Ru nanoparticles with different compositions under annealing treatment. Our observations revealed that the Pt–Ru bimetallic nanoparticles have a Pt-rich core and a Ru-rich shell structure. After annealment at 500 °C, the alloying extent of the Pt–Ru nanoparticles increased, and more Pt atoms appeared on the surface. Notably, subsequent evaluations of the catalytic activity for the methanol oxidation reaction proved that the electrocatalytic performance of Pt/Ru bimetals was increased with the oxidation degree of superficial Ru atoms.