Highly Stable Pt鈥揂u@Ru/C Catalyst Nanoparticles for Methanol Electro-oxidation

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• 作者：Qinggang He ; Badri Shyam ; Masahiko Nishijima ; Xiaofang Yang ; Bruce Koel ; Frank Ernst ; David Ramaker ; Sanjeev Mukerjee
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：January 24, 2013
• 年：2013
• 卷：117
• 期：3
• 页码：1457-1467
• 全文大小：664K
• 年卷期：v.117,no.3(January 24, 2013)
• ISSN：1932-7455

文摘

Among the major obstacles to the successful application of Pt鈥揜u alloys as anode electrocatalysts for direct methanol fuel cells are their low electrocatalytic activities and poor stability under demanding operating conditions. In particular, detrimental is the eventual dissolution of the more oxophilic Ru. In this work, a novel carbon-supported gold-stabilized Pt鈥揂u@Ru catalyst was synthesized using the water-in-oil microemulsion method. The catalyst possesses an enhanced methanol oxidation activity in acid medium and significantly enhanced stability over a commercially available Pt鈥揜u/C catalyst (E-TEK, 60%). This work provides a representative example of stabilization of an oxophilic transition element, Ru, using a unique ternary structure with Au. The stabilized surface and bulk composition are determined through copper under-potential deposition, transmission electron microscopy, X-ray diffractometry, and X-ray photoelectron spectroscopy in conjunction with electrochemical measurements. In situ X-ray absorption spectroscopy analysis revealed that the addition of gold in the Pt鈥揂u@Ru/C catalyst enhances the stability of the catalyst chiefly by interacting electronically with the Pt and Ru to raise their oxidation potentials.