Platinum/Mesoporous WO3 as a Carbon-Free Electrocatalyst with Enhanced Electrochemical Activity for Methanol Oxidation

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• 作者：Xiangzhi Cui ; Jianlin Shi ; Hangrong Chen ; Lingxia Zhang ; Limin Guo ; Jianhua Gao ; Jingbo Li
• 刊名：Journal of Physical Chemistry B
• 出版年：2008
• 出版时间：September 25, 2008
• 年：2008
• 卷：112
• 期：38
• 页码：12024-12031
• 全文大小：446K
• 年卷期：v.112,no.38(September 25, 2008)
• ISSN：1520-5207

文摘

A new type of carbon-free electrode catalyst, Pt/mesoporous WO₃ composite, has been prepared and its electrochemical activity for methanol oxidation has been investigated. The mesoporous tungsten trioxide support was synthesized by a replicating route and the mesoporous composties with Pt loaded were characterized by using X-ray diffraction (XRD), nitrogen sorption, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) techniques. Cyclic voltammetry (CV), line scan voltammetry (LSV) and chronoamperometry (CA) were adopted to characterize the electrochemical activities of the composites. The mesoporous WO₃ showed high surface area, ordered pore structure, and nanosized wall thickness of about 6−7 nm. When a certain amount of Pt nanoparticles were dispersed in the pore structure of mesoporous WO₃, the resultant mesostructured Pt/WO₃ composites exhibit high electro-catalytic activity toward methanol oxidation. The overall electro-catalytic activities of 20 wt % Pt/WO₃ composites are significantly higher than that of commercial 20 wt % Pt/C catalyst and are comparable to the 20 wt % PtRu/C catalyst in the potential region of 0.5−0.7 V. The enhanced electro-catalytic activity is attributed to be resulted from the assistant catalytic effect and the mesoporous structure of WO₃ supports.