Oxygen-Functionalized Highly Mesoporous Carbon Xerogel Based Catalysts for Direct Methanol Fuel Cell Anodes

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• 作者：Cinthia Alegre ; M. Elena G谩lvez ; Estela Baquedano ; Rafael Moliner ; Elena Pastor ; M. Jes煤s L谩zaro
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：June 27, 2013
• 年：2013
• 卷：117
• 期：25
• 页码：13045-13058
• 全文大小：621K
• 年卷期：v.117,no.25(June 27, 2013)
• ISSN：1932-7455

文摘

PtRu catalysts were prepared using a highly mesoporous carbon xerogel submitted to different oxygen functionalization treatments: diluted and concentrated nitric acid as well as gas-phase 5% O₂鈥揘₂ oxidation. Catalysts with 20 wt % loading and equimolar Pt:Ru metallic phase were prepared using an impregnation procedure involving chemical reduction with formic acid. The so-obtained carbon materials, as well as the different catalysts synthesized, were characterized by means of N₂ physisorption, temperature-programmed desorption (TPD), X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry and chronoamperometry were performed to study their activity toward carbon monoxide and methanol oxidation. Functionalization of the carbon support was found to play a definitive role in the interaction between carbon material and the active phase, determining metallic dispersion, alloying degree, and reduction extent. The activity of the catalysts in methanol electro-oxidation was directly related to the metal oxidation state and alloying degree.